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Banegas S, Escobar D, Pinto A, Moncada M, Matamoros G, Valdivia HO, Reyes A, Fontecha G. Asymptomatic Malaria Reservoirs in Honduras: A Challenge for Elimination. Pathogens 2024; 13:541. [PMID: 39057768 PMCID: PMC11280452 DOI: 10.3390/pathogens13070541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/17/2024] [Accepted: 06/21/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030. To accomplish this goal, it is essential to assess the existing strategies employed for malaria control and to address the task of incorporating novel intervention strategies to identify asymptomatic reservoirs. METHODS A survey for detecting asymptomatic cases was carried out in the community of Kaukira, in Gracias a Dios, Honduras, focusing on malaria transmission during 2023. Asymptomatic community members were recruited as participants, malaria screening was performed through a rapid diagnostic test in situ, and a blood sample was collected on filter paper. Highly sensitive molecular assays based on photo-induced electron transfer PCR (PET-PCR) were performed to detect the two species of Plasmodium circulating in Honduras: Plasmodium vivax and Plasmodium falciparum. In addition, the identification of the parasite species was verified by amplifying three genetic markers (Pvmsp3α, Pvmsp3ß, and Pfmsp1). RESULTS A total of 138 participants were recruited, mostly adult women. All individuals tested negative on the rapid diagnostic test. Positive results for malaria were detected by PET-PCR in 17 samples (12.3%). Most samples (12 out of 17) were amplified with a Ct value between 37 and 42, indicating very low parasitemias. Out of the 17 samples, 16 of them also showed amplification in the species assays. There were nine cases of P. falciparum infections and seven cases of P. vivax infections that were further confirmed by nested PCR (nPCR) of Pvmsp3 and Pfmsp1. Parasitemias ranged from 100 p/μL to less than 0.25 p/μL. One sample showed mixed infection. CONCLUSIONS The existence of asymptomatic malaria reservoirs in Honduras can contribute to disease transmission and pose a challenge that may hinder elimination efforts, requiring public health authorities to modify surveillance strategies to identify the disease and treat this population accordingly.
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Affiliation(s)
- Sharon Banegas
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Denis Escobar
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Alejandra Pinto
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Marcela Moncada
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Gabriela Matamoros
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Hugo O. Valdivia
- Department of Parasitology, U.S. Naval Medical Research Unit South (NAMRU SOUTH), Lima 07006, Peru
| | - Allan Reyes
- Unidad de Entomología, Región Sanitaria de Gracias a Dios, Secretaría de Salud de Honduras, Puerto Lempira 33101, Gracias a Dios, Honduras
| | - Gustavo Fontecha
- Instituto de Investigaciones en Microbiología, Facultad de Ciencias, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
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Holzschuh A, Ewnetu Y, Carlier L, Lerch A, Gerlovina I, Baker SC, Yewhalaw D, Haileselassie W, Berhane N, Lemma W, Koepfli C. Plasmodium falciparum transmission in the highlands of Ethiopia is driven by closely related and clonal parasites. Mol Ecol 2024; 33:e17292. [PMID: 38339833 DOI: 10.1111/mec.17292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 12/28/2023] [Accepted: 01/30/2024] [Indexed: 02/12/2024]
Abstract
Malaria cases are frequently recorded in the Ethiopian highlands even at altitudes above 2000 m. The epidemiology of malaria in the Ethiopian highlands, and, in particular, the role of importation by human migration from the highly endemic lowlands is not well understood. We sequenced 187 Plasmodium falciparum samples from two sites in the Ethiopian highlands, Gondar (n = 159) and Ziway (n = 28), using a multiplexed droplet digital PCR (ddPCR)-based amplicon sequencing method targeting 35 microhaplotypes and drug resistance loci. Here, we characterize the parasite population structure and genetic relatedness. We identify moderate parasite diversity (mean HE : 0.54) and low infection complexity (74.9% monoclonal). A significant percentage of infections share microhaplotypes, even across transmission seasons and sites, indicating persistent local transmission. We identify multiple clusters of clonal or near-clonal infections, highlighting high genetic relatedness. Only 6.3% of individuals diagnosed with P. falciparum reported recent travel. Yet, in clonal or near-clonal clusters, infections of travellers were frequently observed first in time, suggesting that parasites may have been imported and then transmitted locally. 31.1% of infections are pfhrp2-deleted and 84.4% pfhrp3-deleted, and 28.7% have pfhrp2/3 double deletions. Parasites with pfhrp2/3 deletions and wild-type parasites are genetically distinct. Mutations associated with resistance to sulphadoxine-pyrimethamine or suggested to reduce sensitivity to lumefantrine are observed at near-fixation. In conclusion, genomic data corroborate local transmission and the importance of intensified control in the Ethiopian highlands.
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Affiliation(s)
- Aurel Holzschuh
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
| | - Yalemwork Ewnetu
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Lise Carlier
- Trinity Centre for Global Health, Trinity College Dublin, Dublin, Ireland
- Noul Inc., Seoul, Republic of Korea
| | - Anita Lerch
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
| | - Inna Gerlovina
- Department of Medicine, Division of HIV, ID and Global Medicine, EPPIcenter Research Program, University of California, San Francisco, California, USA
| | - Sarah Cate Baker
- Trinity Centre for Global Health, Trinity College Dublin, Dublin, Ireland
| | - Delenasaw Yewhalaw
- Tropical and Infectious Disease Research Center, Jimma University, Jimma, Ethiopia
| | | | - Nega Berhane
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Wossenseged Lemma
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
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Jaramillo-Underwood A, Herman C, Jean SE, Nace D, Elder ES, Robinson K, Knipes A, Worrell CM, Fox LM, Desir L, Fayette C, Javel A, Monestime F, Mace KE, Udhayakumar V, Won KY, Chang MA, Lemoine JF, Rogier E. Geospatial analysis of Plasmodium falciparum serological indicators: school versus community sampling in a low-transmission malaria setting. BMC Med 2024; 22:31. [PMID: 38254075 PMCID: PMC10804471 DOI: 10.1186/s12916-023-03145-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 10/31/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Due to low numbers of active infections and persons presenting to health facilities for malaria treatment, case-based surveillance is inefficient for understanding the remaining disease burden in low malaria transmission settings. Serological data through the detection of IgG antibodies from previous malaria parasite exposure can fill this gap by providing a nuanced picture of where sustained transmission remains. Study enrollment at sites of gathering provides a potential approach to spatially estimate malaria exposure and could preclude the need for more intensive community-based sampling. METHODS This study compared spatial estimates of malaria exposure from cross-sectional school- and community-based sampling in Haiti. A total of 52,405 blood samples were collected from 2012 to 2017. Multiplex bead assays (MBAs) tested IgG against P. falciparum liver stage antigen-1 (LSA-1), apical membrane antigen 1 (AMA1), and merozoite surface protein 1 (MSP1). Predictive geospatial models of seropositivity adjusted for environmental covariates, and results were compared using correlations by coordinate points and communes across Haiti. RESULTS Consistent directional associations were observed between seroprevalence and environmental covariates for elevation (negative), air temperature (negative), and travel time to urban centers (positive). Spearman's rank correlation for predicted seroprevalence at coordinate points was lowest for LSA-1 (ρ = 0.10, 95% CI: 0.09-0.11), but improved for AMA1 (ρ = 0.36, 95% CI: 0.35-0.37) and MSP1 (ρ = 0.48, 95% CI: 0.47-0.49). CONCLUSIONS In settings approaching P. falciparum elimination, case-based prevalence data does not provide a resolution of ongoing malaria transmission in the population. Immunogenic antigen targets (e.g., AMA1, MSP1) that give higher population rates of seropositivity provide moderate correlation to gold standard community sampling designs and are a feasible approach to discern foci of residual P. falciparum transmission in an area.
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Affiliation(s)
- Alicia Jaramillo-Underwood
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, 37830, USA
| | - Camelia Herman
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
- CDC Foundation, Atlanta, GA, 30308, USA
| | - Samuel E Jean
- Population Services International, Port-Au-Prince, Haiti
| | - Doug Nace
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - E Scott Elder
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Keri Robinson
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Alaine Knipes
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Caitlin M Worrell
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - LeAnne M Fox
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | | | - Carl Fayette
- IMA World Health, Port-Au-Prince, Haiti
- RTI International, Port-Au-Prince, Haiti
| | - Alain Javel
- IMA World Health, Port-Au-Prince, Haiti
- RTI International, Port-Au-Prince, Haiti
| | | | - Kimberly E Mace
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | | | - Kimberly Y Won
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Michelle A Chang
- US Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Jean F Lemoine
- Ministère de La Santé Publique Et de La Population, Port Au Prince, Haiti
| | - Eric Rogier
- Division of Digestive Diseases and Nutrition, University of Kentucky, Lexington, United States.
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Kebede AM, Sutanto E, Trimarsanto H, Benavente ED, Barnes M, Pearson RD, Siegel SV, Erko B, Assefa A, Getachew S, Aseffa A, Petros B, Lo E, Mohammed R, Yilma D, Rumaseb A, Nosten F, Noviyanti R, Rayner JC, Kwiatkowski DP, Price RN, Golassa L, Auburn S. Genomic analysis of Plasmodium vivax describes patterns of connectivity and putative drivers of adaptation in Ethiopia. Sci Rep 2023; 13:20788. [PMID: 38012191 PMCID: PMC10682486 DOI: 10.1038/s41598-023-47889-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/20/2023] [Indexed: 11/29/2023] Open
Abstract
Ethiopia has the greatest burden of Plasmodium vivax in Africa, but little is known about the epidemiological landscape of parasites across the country. We analysed the genomic diversity of 137 P. vivax isolates collected nine Ethiopian districts from 2012 to 2016. Signatures of selection were detected by cross-country comparisons with isolates from Thailand (n = 104) and Indonesia (n = 111), representing regions with low and high chloroquine resistance respectively. 26% (35/137) of Ethiopian infections were polyclonal, and 48.5% (17/35) of these comprised highly related clones (within-host identity-by-descent > 25%), indicating frequent co-transmission and superinfection. Parasite gene flow between districts could not be explained entirely by geographic distance, with economic and cultural factors hypothesised to have an impact on connectivity. Amplification of the duffy binding protein gene (pvdbp1) was prevalent across all districts (16-75%). Cross-population haplotype homozygosity revealed positive selection in a region proximal to the putative chloroquine resistance transporter gene (pvcrt-o). An S25P variant in amino acid transporter 1 (pvaat1), whose homologue has recently been implicated in P. falciparum chloroquine resistance evolution, was prevalent in Ethiopia (96%) but not Thailand or Indonesia (35-53%). The genomic architecture in Ethiopia highlights circulating variants of potential public health concern in an endemic setting with evidence of stable transmission.
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Affiliation(s)
| | | | - Hidayat Trimarsanto
- Menzies School of Health Research and Charles Darwin University, Casuarina, PO Box 41096, Darwin, NT, 0811, Australia
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Ernest Diez Benavente
- Laboratory of Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mariana Barnes
- Menzies School of Health Research and Charles Darwin University, Casuarina, PO Box 41096, Darwin, NT, 0811, Australia
| | | | | | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Sisay Getachew
- Armauer Hansen Research Unit (AHRI), Addis Ababa, Ethiopia
- Addis Ababa University, Addis Ababa, Ethiopia
- Millipore Sigma (Bioreliance), Rockville, USA
| | - Abraham Aseffa
- Armauer Hansen Research Unit (AHRI), Addis Ababa, Ethiopia
| | | | - Eugenia Lo
- Department of Microbiology and Immunology, College of Medicine, Drexel University, Philadelphia, USA
| | | | - Daniel Yilma
- Jimma University Clinical Trial Unit, Department of Internal Medicine, Jimma University, Jimma, Ethiopia
| | - Angela Rumaseb
- Menzies School of Health Research and Charles Darwin University, Casuarina, PO Box 41096, Darwin, NT, 0811, Australia
| | - Francois Nosten
- Shoklo Malaria Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | | | - Ric N Price
- Menzies School of Health Research and Charles Darwin University, Casuarina, PO Box 41096, Darwin, NT, 0811, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Sarah Auburn
- Menzies School of Health Research and Charles Darwin University, Casuarina, PO Box 41096, Darwin, NT, 0811, Australia.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.
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Getachew H, Demissew A, Abossie A, Habtamu K, Wang X, Zhong D, Zhou G, Lee MC, Hemming-Schroeder E, Bradley L, Degefa T, Hawaria D, Tsegaye A, W Kazura J, Koepfli C, Yan G, Yewhalaw D. Asymptomatic and submicroscopic malaria infections in sugar cane and rice development areas of Ethiopia. Malar J 2023; 22:341. [PMID: 37940948 PMCID: PMC10634149 DOI: 10.1186/s12936-023-04762-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 10/22/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND Water resource development projects, such as dams and irrigation schemes, have a positive impact on food security and poverty reduction. However, such projects could increase prevalence of vector borne disease, such as malaria. This study investigate the impact of different agroecosystems and prevalence of malaria infection in Southwest Ethiopia. METHODS Two cross-sectional surveys were conducted in the dry and wet seasons in irrigated and non-irrigated clusters of Arjo sugarcane and Gambella rice development areas of Ethiopia in 2019. A total of 4464 and 2176 study participants from 1449 households in Arjo and 546 households in Gambella enrolled in the study and blood samples were collected, respectively. All blood samples were microscopically examined and a subset of microscopy negative blood samples (n = 2244) were analysed by qPCR. Mixed effect logistic regression and generalized estimating equation were used to determine microscopic and submicroscopic malaria infection and the associated risk factors, respectively. RESULTS Prevalence by microscopy was 2.0% (88/4464) in Arjo and 6.1% (133/2176) in Gambella. In Gambella, prevalence was significantly higher in irrigated clusters (10.4% vs 3.6%) than in non-irrigated clusters (p < 0.001), but no difference was found in Arjo (2.0% vs 2.0%; p = 0.993). On the other hand, of the 1713 and 531 samples analysed by qPCR from Arjo and Gambella the presence of submicroscopic infection was 1.2% and 12.8%, respectively. Plasmodium falciparum, Plasmodium vivax, and Plasmodium ovale were identified by qPCR in both sites. Irrigation was a risk factor for submicroscopic infection in both Arjo and Gambella. Irrigation, being a migrant worker, outdoor job, < 6 months length of stay in the area were risk factors for microscopic infection in Gambella. Moreover, school-age children and length of stay in the area for 1-3 years were significant predictors for submicroscopic malaria in Gambella. However, no ITN utilization was a predictor for both submicroscopic and microscopic infection in Arjo. Season was also a risk factor for microscopic infection in Arjo. CONCLUSION The study highlighted the potential importance of different irrigation practices impacting on submicroscopic malaria transmission. Moreover, microscopic and submicroscopic infections coupled with population movement may contribute to residual malaria transmission and could hinder malaria control and elimination programmes in the country. Therefore, strengthening malaria surveillance and control by using highly sensitive diagnostic tools to detect low-density parasites, screening migrant workers upon arrival and departure, ensuring adequate coverage and proper utilization of vector control tools, and health education for at-risk groups residing or working in such development corridors is needed.
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Affiliation(s)
- Hallelujah Getachew
- Department of Medical Laboratory Technology, Arbaminch College of Health Sciences, Arbaminch, Ethiopia.
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.
- Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia.
| | - Assalif Demissew
- Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Ambo University, Ambo, Ethiopia
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ashenafi Abossie
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Arbaminch University, Arbaminch, Ethiopia
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia
| | - Kassahun Habtamu
- Menelik II Medical & Health Science College, Addis Ababa, Ethiopia
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Xiaoming Wang
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Elizabeth Hemming-Schroeder
- Center for Vector Born Infectious Diseases (CVID), Department of Microbiology Immunology and Pathology, Colorado State University, Fort Collins, USA
| | - Lauren Bradley
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Teshome Degefa
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Dawit Hawaria
- School of Environmental Health, Hawassa University, Hawassa, Ethiopia
| | - Arega Tsegaye
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Department of Biology, College of Natural Science, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia
| | - James W Kazura
- Biomedical Research Case Western Reserve University, Cleveland, OH, USA
- Center for Global Health & Disease School of Medicine Case, Western Reserve University, Cleveland, OH, USA
| | - Cristian Koepfli
- Department of Biological Sciences 319 Galvin Life Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA92697, USA
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia
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Biruksew A, Demeke A, Birhanu Z, Golassa L, Getnet M, Yewhalaw D. Schoolchildren with asymptomatic malaria are potential hotspot for malaria reservoir in Ethiopia: implications for malaria control and elimination efforts. Malar J 2023; 22:311. [PMID: 37845680 PMCID: PMC10580533 DOI: 10.1186/s12936-023-04736-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/30/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Schoolchildren with asymptomatic malaria infections often go undiagnosed and untreated, serving as reservoirs for infection that hamper malaria control and elimination efforts. In this context, little is known about the magnitude of asymptomatic malaria infections in apparently healthy schoolchildren in Ethiopia. This study was aimed at determining the prevalence of asymptomatic malaria infection and its associated factors in apparently healthy schoolchildren in Ethiopia. METHODS From September 2021 to January 2022, a school-based cross-sectional study was conducted on 994 apparently healthy schoolchildren (aged 6-15 years) selected from 21 primary schools in the Gomma district, of Jimma zone, southwestern Oromia, Ethiopia. A multi-stage sampling technique was used to select schools and participants. After allocating the total sample proportionally to each school and then to each grade, participants were selected using the lottery method from a list of student records (rosters). Finger-pricked blood samples were collected for microscopy blood film preparation and malaria rapid diagnostic test (RDT) (SD Bioline Malaria Ag Pf/Pv). Moreover, dry blood spots (DBSs) were prepared onto filter papers for quantitative real time polymerase chain reaction (qPCR) analysis. RESULTS As determined by RDT and microscopy, the prevalence of asymptomatic malaria was 2.20% and 1.51%, respectively. Using qPCR, the overall prevalence was 5.03% (50/994). Of this, Plasmodium falciparum, Plasmodium vivax and mixed infections accounted for 90%, 6% and 4%, respectively. Submicroscopic asymptomatic malaria infection was also accounted for 70% (35/50) of the overall prevalence. Household head age, nighttime outdoor activities of household heads, family history of malaria, absence of insecticide-treated nets (ITN), and presence of stagnant water around the houses are all significantly associated with asymptomatic malaria infections among schoolchildren. CONCLUSIONS This study found that both RDT and microscopy underestimated the prevalence of asymptomatic malaria in schoolchildren. However, qPCR was able to detect even low levels of parasitaemia and revealed a higher prevalence of asymptomatic submicroscopic malaria infections. The findings imply that schoolchildren with asymptomatic malaria infection are potential hotspot for malaria reservoir that fuels ongoing transmission. Therefore, it is imperative to include schoolchildren and schools in malaria intervention package and equally important is the adoption of more advanced and sensitive diagnostic tools, which would be crucial for successful malaria control and elimination efforts. Targeted interventions for asymptomatic malaria-infected schoolchildren can provide invaluable support to the National Malaria Control Programme in controlling and eventually eliminating the disease.
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Affiliation(s)
- Abdissa Biruksew
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
| | | | - Zewdie Birhanu
- Department of Health, Behavior, and Society, Faculty of Public Health, Institute of Health Jimma University, Jimma, Ethiopia
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Masrie Getnet
- Department of Biostatistics and Epidemiology, Faculty of Public Health, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
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7
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Getachew H, Demissew A, Abossie A, Habtamu K, Wang X, Zhong D, Zhou G, Lee MC, Hemming-Schroeder E, Bradley L, Degefa T, Hawaria D, Tsegaye A, Kazura JW, Koepfli C, Yan G, Yewhalaw D. Asymptomatic and submicroscopic malaria infections in sugar cane and rice development areas of Ethiopia. RESEARCH SQUARE 2023:rs.3.rs-2692688. [PMID: 36993196 PMCID: PMC10055656 DOI: 10.21203/rs.3.rs-2692688/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Background Water resource development projects such as dams and irrigation schemes have a positive impact on food security and poverty reduction but might result in increased prevalence of malaria. Methods Two cross-sectional surveys were conducted in the dry and wet seasons in irrigated and non-irrigated clusters of Arjo sugarcane and Gambella rice development areas of Ethiopia in 2019. A total of 4464 and 2176 blood samples were collected from Arjo and Gambella. A subset of 2244 microscopy negative blood samples were analyzed by PCR. Results Prevalence by microscopy was 2.0% (88/4464) in Arjo and 6.1% (133/2176) in Gambella. In Gambella, prevalence was significantly higher in irrigated clusters (10.4% vs 3.6%) than in non-irrigated clusters (p < 0.001), but no difference was found in Arjo (2.0% vs 2.0%; p = 0.993). Level of education was an individual risk factors associated with infection in Arjo [AOR: 3.2; 95%CI (1.27-8.16)] and in Gambella [AOR: 1.7; 95%CI (1.06-2.82)]. While duration of stay in the area for < 6 months [AOR: 4.7; 95%CI (1.84-12.15)] and being a migrant worker [AOR: 4.7; 95%CI (3.01-7.17)] were risk factors in Gambella. Season [AOR: 15.9; 95%CI (6.01-42.04)], no ITN utilization [AOR: 22.3; 95%CI (7.74-64.34)] were risk factors in Arjo, and irrigation [AOR: 2.4; 95%CI (1.45-4.07)] and family size [AOR: 2.3; 95%CI (1.30-4.09)] risk factors in Gambella. Of the 1713 and 531 randomly selected smear negative samples from Arjo and Gambella and analyzed by PCR the presence of Plasmodium infection was 1.2% and 12.8%, respectively. P. falciparum, P. vivax, and P. ovale were identified by PCR in both sites. Conclusion Strengthening malaria surveillance and control in project development areas and proper health education for at-risk groups residing or working in such development corridors is needed.
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Affiliation(s)
- Hallelujah Getachew
- Department of Medical Laboratory Technology, Arbaminch College of Health Sciences, Arbaminch
| | - Assalif Demissew
- Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Ambo University, Ambo
| | - Ashenafi Abossie
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Arbaminch University, Arbaminch
| | | | - Xiaoming Wang
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Elizabeth Hemming-Schroeder
- Center for Vector Born Infectious Diseases (CVID), Department of Microbiology Immunology and Pathology, Colorado State University
| | - Lauren Bradley
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Teshome Degefa
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma
| | - Dawit Hawaria
- Hawassa University, School of Environmental Health, Hawassa
| | - Arega Tsegaye
- Department of Biology, College of Natural Science, Jimma University
| | - James W Kazura
- Biomedical Research Case Western Reserve University, Cleveland, Ohio
| | - Cristian Koepfli
- Department of Biological Sciences 319 Galvin Life Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA 92697
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma
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8
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Aidoo EK, Aboagye FT, Botchway FA, Osei-Adjei G, Appiah M, Duku-Takyi R, Sakyi SA, Amoah L, Badu K, Asmah RH, Lawson BW, Krogfelt KA. Reactive Case Detection Strategy for Malaria Control and Elimination: A 12 Year Systematic Review and Meta-Analysis from 25 Malaria-Endemic Countries. Trop Med Infect Dis 2023; 8:tropicalmed8030180. [PMID: 36977181 PMCID: PMC10058581 DOI: 10.3390/tropicalmed8030180] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/23/2023] [Accepted: 03/09/2023] [Indexed: 03/30/2023] Open
Abstract
Reactive case detection (RACD) is the screening of household members and neighbors of index cases reported in passive surveillance. This strategy seeks asymptomatic infections and provides treatment to break transmission without testing or treating the entire population. This review discusses and highlights RACD as a recommended strategy for the detection and elimination of asymptomatic malaria as it pertains in different countries. Relevant studies published between January 2010 and September 2022 were identified mainly through PubMed and Google Scholar. Search terms included "malaria and reactive case detection", "contact tracing", "focal screening", "case investigation", "focal screen and treat". MedCalc Software was used for data analysis, and the findings from the pooled studies were analyzed using a fixed-effect model. Summary outcomes were then presented using forest plots and tables. Fifty-four (54) studies were systematically reviewed. Of these studies, 7 met the eligibility criteria based on risk of malaria infection in individuals living with an index case < 5 years old, 13 met the eligibility criteria based on risk of malaria infection in an index case household member compared with a neighbor of an index case, and 29 met the eligibility criteria based on risk of malaria infection in individuals living with index cases, and were included in the meta-analysis. Individuals living in index case households with an average risk of 2.576 (2.540-2.612) were more at risk of malaria infection and showed pooled results of high variation heterogeneity chi-square = 235.600, (p < 0.0001) I2 = 98.88 [97.87-99.89]. The pooled results showed that neighbors of index cases were 0.352 [0.301-0.412] times more likely to have a malaria infection relative to index case household members, and this result was statistically significant (p < 0.001). The identification and treatment of infectious reservoirs is critical to successful malaria elimination. Evidence to support the clustering of infections in neighborhoods, which necessitates the inclusion of neighboring households as part of the RACD strategy, was presented in this review.
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Affiliation(s)
- Ebenezer Krampah Aidoo
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana
| | - Frank Twum Aboagye
- Biomedical and Public Health Research Unit, Council for Scientific and Industrial Research-Water Research Institute, Accra AH 38, Ghana
| | - Felix Abekah Botchway
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana
| | - George Osei-Adjei
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana
| | - Michael Appiah
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana
| | - Ruth Duku-Takyi
- Department of Medical Laboratory Technology, Accra Technical University, Accra GP 561, Ghana
| | - Samuel Asamoah Sakyi
- Department of Molecular Medicine, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana
| | - Linda Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra LG 581, Ghana
| | - Kingsley Badu
- Department of Theoretical & Applied Biology, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana
| | - Richard Harry Asmah
- Department of Biomedical Sciences, School of Basic and Biomedical Science, University of Health & Allied Sciences, Ho PMB 31, Ghana
| | - Bernard Walter Lawson
- Department of Theoretical & Applied Biology, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi AK 039, Ghana
| | - Karen Angeliki Krogfelt
- Department of Science and Environment, Unit of Molecular and Medical Biology, The PandemiX Center, Roskilde University, 4000 Roskilde, Denmark
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300 Copenhagen, Denmark
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9
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Komaki-Yasuda K, Kutsuna S, Kawaguchi M, Kamei M, Uchihashi K, Nakamura K, Nakamoto T, Ohmagari N, Kano S. Clinical performance testing of the automated haematology analyzer XN-31 prototype using whole blood samples from patients with imported malaria in Japan. Malar J 2022; 21:229. [PMID: 35907857 PMCID: PMC9338637 DOI: 10.1186/s12936-022-04247-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 07/20/2022] [Indexed: 11/10/2022] Open
Abstract
Background The automated haematology analyzer XN-31 prototype (XN-31p) is a new flow cytometry-based device developed to measure the number and the ratio of malaria-infected red blood cells (MI-RBC) with a complete blood count (CBC). The XN-31p can provide results in about one minute and also can simultaneously provide information on the malaria parasite (Plasmodium) species. In this study, clinical testing of the XN-31p was performed using blood samples from patients with imported malaria in Japan. Methods Blood samples were collected from 80 patients who visited the hospital of the National Center for Global Health and Medicine, Tokyo, Japan, for malaria diagnosis from January 2017 to January 2019. The test results by the XN-31p were compared with those by other standard methods, such as microscopic observation, rapid diagnostic tests and the nested PCR. Results Thirty-three patients were diagnosed by the nested PCR as being malaria positive (28 Plasmodium falciparum, 2 Plasmodium vivax, 1 Plasmodium knowlesi, 1 mixed infection of P. falciparum and Plasmodium malariae, and 1 mixed infection of P. falciparum and Plasmodium ovale), and the other 47 were negative. The XN-31p detected 32 patients as “MI-RBC positive”, which almost matched the results by the nested PCR and, in fact, completely matched with the microscopic observations. The ratio of RBCs infected with malaria parasites as determined by the XN-31p showed a high correlation coefficient of more than 0.99 with the parasitaemia counted under microscopic observation. The XN-31p can analyse the size and nucleic acid contents of each cell, and the results were visualized on a two-dimensional cytogram termed the “M scattergram”. Information on species and developmental stages of the parasites could also be predicted from the patterns visualized in the M scattergrams. The XN-31p showed a positive coincidence rate of 0.848 with the nested PCR in discriminating P. falciparum from the other species. Conclusions The XN-31p could rapidly provide instructive information on the ratio of MI-RBC and the infecting Plasmodium species. It was regarded to be of great help for the clinical diagnosis of malaria. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04247-x.
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Affiliation(s)
- Kanako Komaki-Yasuda
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Satoshi Kutsuna
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Miki Kawaguchi
- Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan
| | - Mina Kamei
- Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan
| | - Kinya Uchihashi
- Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan
| | - Keiji Nakamura
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Takato Nakamoto
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Norio Ohmagari
- Disease Control and Prevention Center of National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Shigeyuki Kano
- Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan.
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Cao Y, Lu G, Zhou H, Wang W, Liu Y, Yang M, Liang C, Zhu G, Cao J. Case-based malaria surveillance and response: implementation of 1-3-7 approach in Jiangsu Province, China. ADVANCES IN PARASITOLOGY 2022; 116:1-31. [PMID: 35752445 DOI: 10.1016/bs.apar.2022.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Following initiation of China's National Malaria Elimination Action Plan (NMEAP) in 2010, China's 1-3-7 surveillance and response approach was developed and rolled out in China to facilitate the malaria control programme and accelerate the progress of malaria elimination. Innovative strategies and interventions have been developed and implemented in Jiangsu Province to facilitate case-based malaria surveillance and response. A total of 9879 malaria cases were reported in Jiangsu Province from 2001 to 2020. Since 2012, no indigenous malaria cases have been reported in Jiangsu Province. However, in recent years, there has been a substantial increase of imported cases from abroad. To continue improving the malaria surveillance and response system, Jiangsu Province has conducted population-based health education to improve the healthcare seeking behaviour of malaria patients, strengthened the capacity of health facilities to improve the performance of malaria diagnosis and treatment, and strengthened health workforce capacity to improve the implementation of 1-3-7 approach. Continually improving surveillance and response system can play a critical role in the early detection and rapid response of individual malaria cases and prevent the re-establishment of malaria.
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Affiliation(s)
- Yuanyuan Cao
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Guangyu Lu
- School of Public Health, Medical College of Yangzhou University, Yangzhou University, Yangzhou, Jiangsu, PR China
| | - Huayun Zhou
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Weiming Wang
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Yaobao Liu
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Mengmeng Yang
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Cheng Liang
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China
| | - Guoding Zhu
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, PR China.
| | - Jun Cao
- Key Laboratory of National Health Commission (NHC) on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, PR China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, PR China.
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11
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Melese Y, Alemu M, Yimer M, Tegegne B, Tadele T. Asymptomatic Malaria in Households and Neighbors of Laboratory Confirmed Cases in Raya Kobo District, Northeast Ethiopia. Ethiop J Health Sci 2022; 32:623-630. [PMID: 35813680 PMCID: PMC9214748 DOI: 10.4314/ejhs.v32i3.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/13/2022] [Indexed: 11/17/2022] Open
Abstract
Background Malaria is the leading vector-borne parasitic disease that is causing high morbidity and mortality worldwide. So far huge efforts to control and eliminate malaria are hindered by the occurrence of asymptomatic carriers that are a potential source of infection. Yet, there is a scarcity of data nationally and in the current study area as well. Therefore, this study was aimed to assess the prevalence of asymptomatic malaria in Northeast Ethiopia. Methods A community-based cross-sectional study was conducted in 2019 involving a total of 270 study participants recruited via purposive non-probability sampling technique. A structured questionnaire was used to collect data on sociodemographic characteristics, individual and household factors related to asymptomatic malaria. Data were entered in Epi Data 3.1 version and analyzed by using SPSS version 20, and p< 0.05 was considered statistically significant. Results The overall prevalence of asymptomatic malaria was 7.0%, with 3.0%, 5.2%, and 12.0%, respectively by Rapid diagnostic tests (RDT), Microscopy and Polymerase chain reaction (PCR). The majority of infections (73.7%) were identified from index households. Previous malaria history (AOR: 4.030, 95% CI: 1.021-15.903), living with index cases (AOR: 3.880, 95% CI: 1.275-11.806) and family size > 6 members (AOR: 4.820, 95% CI: 1.260-18.437) were significant predictors of asymptomatic malaria. Conclusion Reactive case detection had identified considerably higher asymptomatic malaria cases in the community. Therefore, active case investigation should be established in the community by tracking the symptomatic cases at the health facilities.
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Affiliation(s)
| | - Megbaru Alemu
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
| | - Mulat Yimer
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
| | | | - Tigist Tadele
- Department of Biomedical Sciences, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
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12
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Carlier L, Baker SC, Huwe T, Yewhalaw D, Haileselassie W, Koepfli C. qPCR in a suitcase for rapid Plasmodium falciparum and Plasmodium vivax surveillance in Ethiopia. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000454. [PMID: 36962431 PMCID: PMC10021179 DOI: 10.1371/journal.pgph.0000454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/23/2022] [Indexed: 11/19/2022]
Abstract
Many Plasmodium spp. infections, both in clinical and asymptomatic patients, are below the limit of detection of light microscopy or rapid diagnostic test (RDT). Molecular diagnosis by qPCR can be valuable for surveillance, but is often hampered by absence of laboratory capacity in endemic countries. To overcome this limitation, we optimized and tested a mobile qPCR laboratory for molecular diagnosis in Ziway, Ethiopia, where transmission intensity is low. Protocols were optimized to achieve high throughput and minimize costs and weight for easy transport. 899 samples from febrile patients and 1021 samples from asymptomatic individuals were screened by local microscopy, RDT, and qPCR within a period of six weeks. 34/52 clinical Plasmodium falciparum infections were missed by microscopy and RDT. Only 4 asymptomatic infections were detected. No hrp2 deletions were observed among 25 samples typed, but 19/24 samples carried hrp3 deletions. The majority (25/41) of Plasmodium vivax infections (1371 samples screened) were found among asymptomatic individuals. All asymptomatic P. vivax infections were negative by microscopy and RDT. In conclusion, the mobile laboratory described here can identify hidden parasite reservoirs within a short period of time, and thus inform malaria control activities.
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Affiliation(s)
- Lise Carlier
- Trinity College Dublin, Dublin, Ireland
- Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Sarah Cate Baker
- Trinity College Dublin, Dublin, Ireland
- Oregon Health & Science University, Portland, Oregon, United States of America
| | - Tiffany Huwe
- Department of Biological Sciences & Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Delenasaw Yewhalaw
- Tropical and Infectious Disease Research Center, Jimma University, Jimma, Ethiopia
| | | | - Cristian Koepfli
- Department of Biological Sciences & Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
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13
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Quang HH, Chavchich M, Trinh NTM, Manh ND, Edstein MD, Martin NJ, Edgel KA. Cross-sectional survey of asymptomatic malaria in Dak Nong province in the Central Highlands of Vietnam for the malaria elimination roadmap. PLoS One 2021; 16:e0258580. [PMID: 34669697 PMCID: PMC8528296 DOI: 10.1371/journal.pone.0258580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 09/30/2021] [Indexed: 12/25/2022] Open
Abstract
Asymptomatic parasite carriers represent a "silent" infective reservoir for malaria transmission and contributes to malaria persistence. However, limited data are available on asymptomatic malaria in Vietnam. Between November 2018 and March 2019, we conducted a malaria epidemiological survey of asymptomatic people (children ≥ 10 years old and adults ≥18 years old, n = 2,809) residing in three communes in Tuy Duc district, Dak Nong province in the Central Highlands of Vietnam. Based on the national stratification of malaria risk, Dak Buk So, Dak Ngo and Quang Truc communes were classified by the National Malaria Control Programme as low, moderate and high malaria endemic areas, respectively. Using participants' finger prick blood samples, malaria parasites were detected by one-step reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The median age (Interquartile Range) for adults and children were 35 years (26-50) and 12 years (11-14), respectively. The prevalence of asymptomatic malaria was 1.7% (22/1,328), 3.5% (31/890) and 12.2% (72/591) for participants from Dak Buk So, Dak Ngo and Quang Truc, respectively. The prevalence of asymptomatic malaria was lower in children compared to adults: 2.6% (9/352) versus 4.7% (116/2,457) (Odds Ratio 0.53, 95% Confidence Interval 0.28 to1.02). Ownership of long-lasting insecticide-treated bed nets and hammocks was 97.1%, 99.0% and 94.7% for participants in Dak Buk So, Dak Ngo and Quang Truc, respectively, however, only 66.0%, 57.3% and 42.8% of the participants reported using bed nets every night. Of the several risk factors examined, going to the forest two weeks prior to enrolment into the study and sleeping in the forest had a significant association with participants being infected with asymptomatic malaria in Quang Truc, but not in the other two communes. Knowledge of the prevalence and distribution of asymptomatic malaria will help design and evaluate future intervention strategies for malaria elimination in Vietnam.
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Affiliation(s)
- Huynh Hong Quang
- Institute of Malariology, Parasitology and Entomology, Quy Nhon, Vietnam
| | - Marina Chavchich
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | | | | | - Michael D. Edstein
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
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14
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Ketema T, Bacha K, Getahun K, del Portillo HA, Bassat Q. Plasmodium vivax epidemiology in Ethiopia 2000-2020: A systematic review and meta-analysis. PLoS Negl Trop Dis 2021; 15:e0009781. [PMID: 34525091 PMCID: PMC8476039 DOI: 10.1371/journal.pntd.0009781] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/27/2021] [Accepted: 09/01/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Ethiopia is one of the scarce African countries where Plasmodium vivax and P. falciparum co-exist. There has been no attempt to derive a robust prevalence estimate of P. vivax in the country although a clear understanding of the epidemiology of this parasite is essential for informed decisions. This systematic review and meta-analysis, therefore, is aimed to synthesize the available evidences on the distribution of P. vivax infection by different locations/regions, study years, eco-epidemiological zones, and study settings in Ethiopia. METHODS This study was conducted in accordance with Preferred Reposting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Studies conducted and published over the last two decades (2000 to 2020) that reported an estimate of P. vivax prevalence in Ethiopia were included. The Cochrane Q (χ2) and the I2 tests were used to assess heterogeneity, and the funnel plot and Egger's test were used to examine publication bias. A p-value of the χ2 test <0.05 and an I2 value >75% were considered presence of considerable heterogeneity. Random effect models were used to obtain pooled estimate of P. vivax infection prevalence. This study is registered with PROSPERO (International Prospective Register of Systematic Reviews): ID CRD42020201761. RESULTS We screened 4,932 records and included 79 studies that enrolled 1,676,659 confirmed malaria cases, from which 548,214 (32.69%) were P. vivax infections and 1,116,581 (66.59%) were due to P. falciparum. The rest were due to mixed infections. The pooled estimate of P. vivax prevalence rate was 8.93% (95% CI: 7.98-9.88%) with significant heterogeneity (I2 = 100%, p<0.0001). Regional differences showed significant effects (p<0.0001, and I2 = 99.4%) on the pooled prevalence of P. vivax, while study years (before and after the scaling up of interventional activities) did not show significant differences (p = 0.9, I2 = 0%). Eco-epidemiological zones considered in the analysis did show a significant statistical effect (p<0.001, I2 = 78.5%) on the overall pooled estimate prevalence. Also, the study setting showed significant differences (p = 0.001, and I2 = 90.3%) on the overall prevalence, where significant reduction of P. vivax prevalence (4.67%, 95%CI: 1.41-7.93%, p<0.0001) was observed in studies conducted at the community level. The studies included in the review demonstrated lack of publication bias qualitatively (symmetrical funnel plot) and quantitatively [Egger's test (coefficient) = -2.97, 95% CI: -15.06-9.13, p = 0.62]. CONCLUSION The estimated prevalence of P. vivax malaria in Ethiopia was 8.93% with P. vivax prevailing in the central west region of Ethiopia, but steadily extending to the western part of the country. Its distribution across the nation varies according to geographical location, study setting and study years.
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Affiliation(s)
- Tsige Ketema
- Jimma University, College of Natural Sciences, Department of Biology, Jimma, Ethiopia
- ISGlobal, Institute for Global Health, Hospital Clinic-Universitat de Barcelona, Barcelona, Spain
- * E-mail:
| | - Ketema Bacha
- Jimma University, College of Natural Sciences, Department of Biology, Jimma, Ethiopia
| | - Kefelegn Getahun
- Jimma University, College of Social Sciences and Humanity, Department of Geography and Environmental Studies, Jimma, Ethiopia
| | - Hernando A. del Portillo
- ISGlobal, Institute for Global Health, Hospital Clinic-Universitat de Barcelona, Barcelona, Spain
- IGTP, Germans Trias i Pujol Health Research Institute, Badalona, Spain
- ICREA, Catalan Institution for Research and Advanced Studies, Barcelona, Spain
| | - Quique Bassat
- ISGlobal, Institute for Global Health, Hospital Clinic-Universitat de Barcelona, Barcelona, Spain
- ICREA, Catalan Institution for Research and Advanced Studies, Barcelona, Spain
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15
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Minakawa N, Kongere JO, Sonye GO, Lutiali PA, Awuor B, Kawada H, Isozumi R, Futami K. Long-Lasting Insecticidal Nets Incorporating Piperonyl Butoxide Reduce the Risk of Malaria in Children in Western Kenya: A Cluster Randomized Controlled Trial. Am J Trop Med Hyg 2021; 105:461-471. [PMID: 34125699 PMCID: PMC8437186 DOI: 10.4269/ajtmh.20-1069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 03/22/2021] [Indexed: 11/10/2022] Open
Abstract
Malaria vectors have acquired an enzyme that metabolizes pyrethroids. To tackle this problem, we evaluated long-lasting insecticidal nets incorporating piperonyl butoxide (PBO-LLINs) with a community-based cluster randomized control trial in western Kenya. The primary endpoints were anopheline density and Plasmodium falciparum polymerase chain reaction (PCR)-positive prevalence (PCRpfPR) of children aged 7 months to 10 years. Four clusters were randomly selected for each of the treatment and control arms (eight clusters in total) from 12 clusters, and PBO-LLINs and standard LLINs were distributed in February 2011 to 982 and 1,028 houses for treatment and control arms, respectively. Entomological surveys targeted 20 houses in each cluster, and epidemiological surveys targeted 150 children. Cluster-level permutation tests evaluated the effectiveness using the fitted values from individual level regression models adjusted for baseline. Bootstrapping estimated 95% confidence intervals (CIs). The medians of anophelines per house were 1.4 (interquartile range [IQR]: 2.3) and 3.4 (IQR: 3.7) in the intervention and control arms after 3 months, and 0.4 (IQR: 0.2) and 1.6 (IQR: 0.5) after 10 months, respectively. The differences were -2.5 (95% CI: -6.4 to -0.6) and -1.3 (95% CI: -2.0 to -0.7), respectively. The datasets of 861 and 775 children were analyzed in two epidemiological surveys. The median PCRpfPRs were 25% (IQR: 11%) in the intervention arm and 52% (IQR: 11%) in the control arm after 5 months and 33% (IQR: 11%) and 45% (IQR: 5%) after 12 months. The PCRpfPR ratios were 0.67 (95% CI: 0.38, 0.91) and 0.74 (95% CI: 0.53, 0.90), respectively. We confirmed the superiority of PBO-LLINs.
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Affiliation(s)
- Noboru Minakawa
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - James O. Kongere
- Kenya Medical Research Institute, Nairobi, Kenya
- Center for Research in Tropical Medicine and Community Development (CRTMCD), Nairobi, Kenya
| | | | - Peter A. Lutiali
- Kenya Medical Research Institute, Nairobi, Kenya
- Center for Research in Tropical Medicine and Community Development (CRTMCD), Nairobi, Kenya
| | | | - Hitoshi Kawada
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Rie Isozumi
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Kyoko Futami
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
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Motshoge T, Haiyambo DH, Ayanful-Torgby R, Aleksenko L, Ntebela D, Malleret B, Rénia L, Peloewetse E, Paganotti GM, Quaye IK. Recent Molecular Assessment of Plasmodium vivax and Plasmodium falciparum Asymptomatic Infections in Botswana. Am J Trop Med Hyg 2021; 104:2159-2164. [PMID: 33939635 PMCID: PMC8176517 DOI: 10.4269/ajtmh.21-0083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/09/2021] [Indexed: 01/05/2023] Open
Abstract
In 2016, we reported the presence of Plasmodium vivax in Botswana through active case detection. A real-time PCR was used during a similar study in 10 districts to assess changes in the P. vivax prevalence. We assessed 1,614 children (2-13 years of age) for hemoglobin (Hb; g/dL) and Plasmodium parasites. The median age of all participants was 5.0 years (25th percentile, 3 years; 75th percentile, 8 years). The median Hb (g/dL) level was 12.1, but 18.3% of the participants had anemia (Hb < 11.0 g/dL); these participants were clustered in the younger than 5 years age group in all districts (P < 0.001). The risk of anemia decreased with age 5 years or older (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.197-0.34; P < 0.001). The prevalence rates of Plasmodium parasites were as follows: P. vivax, 12.7%; P. falciparum, 12.7%; P. malariae, 0.74%; and P. ovale (P. ovale curtisi), 0.68%. Mixed infection rates were as follows: P. falciparum and P. vivax, 2.35%; P. falciparum and P. ovale curtisi, 0.56%; P. vivax and P. malariae, 0.06%; and P. falciparum and P. malariae, 0.68%. The infections were largely asymptomatic (99.6%). Using logistic regression, the risk of infection with P. vivax was highest in Kweneng East (OR, 6.2; 95% CI, 2.9-13.1), followed by South East (OR, 5.6; 95% CI, 2.5-12.3) and Ngami (OR, 5.1; 95% CI, 2.2-12.0). Compared to the risk of infection for children younger than 5 years, the risk of infection decreased for children 5 years or older in regions with high rates of P. vivax and P. falciparum infections. P. vivax and P. falciparum have expanded within the asymptomatic population in Botswana; therefore, careful attention is required for their elimination.
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Affiliation(s)
- Thato Motshoge
- University of Botswana, Department of Biological Science, Gaborone, Botswana
| | | | - Ruth Ayanful-Torgby
- Regent University College of Science and Technology, Department of Engineering, Computing and Allied Health Sciences, Accra, Ghana
- Biomedical and Public Health Research Unit, Council for Scientific and Industrial Research–Water Research Institute, Council Close, Accra, Ghana
| | | | - Davies Ntebela
- National Malaria Program Ministry of Health and Wellness, Gaborone, Botswana
| | - Benoit Malleret
- Department of Microbiology and Immunology, Immunology Translational Research Program, Yong Loo Lin School of Medicine, Immunology Program, Life Sciences Institute, National University of Singapore, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore
| | - Laurent Rénia
- A*STAR Infectious Diseases Laboratories, Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore
| | - Elias Peloewetse
- University of Botswana, Department of Biological Science, Gaborone, Botswana
| | - Giacomo Maria Paganotti
- Botswana–University of Pennsylvania Partnership, University of Botswana, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
| | - Isaac K. Quaye
- Regent University College of Science and Technology, Department of Engineering, Computing and Allied Health Sciences, Accra, Ghana
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Hailemeskel E, Tebeje SK, Behaksra SW, Shumie G, Shitaye G, Keffale M, Chali W, Gashaw A, Ashine T, Drakeley C, Bousema T, Gadisa E, Tadesse FG. The epidemiology and detectability of asymptomatic plasmodium vivax and plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia. Malar J 2021; 20:59. [PMID: 33482841 PMCID: PMC7821398 DOI: 10.1186/s12936-021-03587-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia. METHOD A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API > 0 and < 5), moderate (API ≥ 5 and < 100) and high transmission (API ≥ 100) and detectability of infections was assessed in these settings. RESULTS In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6-7.2, P = 0.002) and high endemic settings (AOR = 5.1; 95% CI 2.6-9.9, P < 0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95% CI 0.9-1.0, P = 0.013) declined with age. CONCLUSIONS Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.
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Affiliation(s)
- Elifaged Hailemeskel
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Biomedical Sciences, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
- Department of Biology, College of Natural and Computational Sciences, Wollo University, PO Box, 1145, Dessie, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Surafel K Tebeje
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Sinknesh W Behaksra
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Girma Shumie
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Getasew Shitaye
- Department of Biomedical Sciences, School of Medical Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Migbaru Keffale
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Wakweya Chali
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Abrham Gashaw
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Ashine
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Endalamaw Gadisa
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Fitsum G Tadesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia.
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands.
- Institute of Biotechnology, Addis Ababa University, PO Box, 1176, Addis Ababa, Ethiopia.
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Spatial and genetic clustering of Plasmodium falciparum and Plasmodium vivax infections in a low-transmission area of Ethiopia. Sci Rep 2020; 10:19975. [PMID: 33203956 PMCID: PMC7672087 DOI: 10.1038/s41598-020-77031-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/02/2020] [Indexed: 11/23/2022] Open
Abstract
The distribution of malaria infections is heterogeneous in space and time, especially in low transmission settings. Understanding this clustering may allow identification and targeting of pockets of transmission. In Adama district, Ethiopia, Plasmodium falciparum and P. vivax malaria patients and controls were examined, together with household members and immediate neighbors. Rapid diagnostic test and quantitative PCR (qPCR) were used for the detection of infections that were genetically characterized by a panel of microsatellite loci for P. falciparum (26) and P. vivax (11), respectively. Individuals living in households of clinical P. falciparum patients were more likely to have qPCR detected P. falciparum infections (22.0%, 9/41) compared to individuals in control households (8.7%, 37/426; odds ratio, 2.9; 95% confidence interval, 1.3–6.4; P = .007). Genetically related P. falciparum, but not P. vivax infections showed strong clustering within households. Genotyping revealed a marked temporal cluster of P. falciparum infections, almost exclusively comprised of clinical cases. These findings uncover previously unappreciated transmission dynamics and support a rational approach to reactive case detection strategies for P. falciparum in Ethiopia.
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Submicroscopic malaria infection is not associated with fever in cross-sectional studies in Malawi. Malar J 2020; 19:233. [PMID: 32600362 PMCID: PMC7322713 DOI: 10.1186/s12936-020-03296-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/17/2020] [Indexed: 11/10/2022] Open
Abstract
Background Submicroscopic Plasmodium falciparum infections are widespread in many areas. However, the contribution of these infections to symptomatic malaria is not well understood. This study evaluated whether participants with submicroscopic P. falciparum infections have higher prevalence of fever than uninfected participants in southern Malawi. Methods A total of 16,650 children and adults were enrolled in the course of six cross-sectional surveys during the dry season (October–November) and after the rainy season (April–May) between 2012 and 2014 in three districts in southern Malawi. Demographic and socioeconomic data were collected in conjunction with data on clinical histories, use of malaria preventive measures, and anti-malarial medication taken within 2 weeks of the survey. Axillary temperatures were measured, and blood samples were collected for P. falciparum detection by microscopy and PCR. Participants without malaria parasites detected on microscopy but with a positive PCR for P. falciparum were defined as having submicroscopic infection. Fever was defined as having any one of: reported fever in the past 2 weeks, reported fever in the past 48 h, or a temperature of ≥ 37.5 °C measured at the time of interview. Results Submicroscopic P. falciparum infections and fever were both detected in 9% of the study population. In the final analysis adjusted for clustering within household and enumeration area, having submicroscopic P. falciparum infection was associated with reduced odds of fever in the dry season (odds ratio = 0.52; 95% CI 0.33–0.82); the association in the rainy season did not achieve statistical significance (odds ratio = 1.20; 95% CI 0.91–1.59). The association between submicroscopic infection and fever was consistent across all age groups. When the definition of fever was limited to temperature of ≥ 37.5 °C measured at the time of interview, the association was not statistically significant in either the rainy or dry season. Conclusions In this series of cross-sectional studies in southern Malawi, submicroscopic P. falciparum infection was not associated with increased risk of fever. Submicroscopic detection of the malaria parasite is important in efforts to decrease transmission but is not essential for the clinical recognition of malaria disease.
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20
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Oboh MA, Singh US, Ndiaye D, Badiane AS, Ali NA, Bharti PK, Das A. Presence of additional Plasmodium vivax malaria in Duffy negative individuals from Southwestern Nigeria. Malar J 2020; 19:229. [PMID: 32590997 PMCID: PMC7318376 DOI: 10.1186/s12936-020-03301-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/17/2020] [Indexed: 11/13/2022] Open
Abstract
Background Malaria in sub-Saharan Africa (sSA) is thought to be mostly caused by Plasmodium falciparum. Recently, growing reports of cases due to Plasmodium ovale, Plasmodium malariae, and Plasmodium vivax have been increasingly observed to play a role in malaria epidemiology in sSA. This in fact is due to the usage of very sensitive diagnostic tools (e.g. PCR), which have highlighted the underestimation of non-falciparum malaria in this sub-region. Plasmodium vivax was historically thought to be absent in sSA due to the high prevalence of the Duffy negativity in individuals residing in this sub-continent. Recent studies reporting detection of vivax malaria in Duffy-negative individuals from Mali, Mauritania, Cameroon challenge this notion. Methods Following previous report of P. vivax in Duffy-negative individuals in Nigeria, samples were further collected and assessed RDT and/or microscopy. Thereafter, malaria positive samples were subjected to conventional PCR method and DNA sequencing to confirm both single/mixed infections as well as the Duffy status of the individuals. Results Amplification of Plasmodium gDNA was successful in 59.9% (145/242) of the evaluated isolates and as expected P. falciparum was the most predominant (91.7%) species identified. Interestingly, four P. vivax isolates were identified either as single (3) or mixed (one P. falciparum/P. vivax) infection. Sequencing results confirmed all vivax isolates as truly vivax malaria and the patient were of Duffy-negative genotype. Conclusion Identification of additional vivax isolates among Duffy-negative individuals from Nigeria, substantiate the expanding body of evidence on the ability of P. vivax to infect RBCs that do not express the DARC gene. Hence, such genetic-epidemiological study should be conducted at the country level in order to evaluate the true burden of P. vivax in Nigeria.
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Affiliation(s)
- Mary Aigbiremo Oboh
- Medical Research Council Unit The Gambia at LSHTM, Fajara, P.O. Box 273, Banjul, Gambia.
| | - Upasana Shyamsunder Singh
- School of Earth and Environmental Sciences, University of Manchester, Manchester, UK.,Genomic Epidemiology Laboratory, Division of Vector Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, India
| | - Daouda Ndiaye
- Parasitology and Mycology Laboratory, Université Cheikh Anta Diop, Dakar, Senegal
| | - Aida Sadikh Badiane
- Parasitology and Mycology Laboratory, Université Cheikh Anta Diop, Dakar, Senegal
| | - Nazia Anwar Ali
- National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, 482003, India
| | - Praveen Kumar Bharti
- National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, 482003, India
| | - Aparup Das
- Genomic Epidemiology Laboratory, Division of Vector Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, India.
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21
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Assefa A, Ahmed AA, Deressa W, Wilson GG, Kebede A, Mohammed H, Sassine M, Haile M, Dilu D, Teka H, Murphy MW, Sergent S, Rogier E, Zhiyong Z, Wakeman BS, Drakeley C, Shi YP, Von Seidlein L, Hwang J. Assessment of subpatent Plasmodium infection in northwestern Ethiopia. Malar J 2020; 19:108. [PMID: 32131841 PMCID: PMC7057598 DOI: 10.1186/s12936-020-03177-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/22/2020] [Indexed: 12/30/2022] Open
Abstract
Background Ethiopia has set a goal for malaria elimination by 2030. Low parasite density infections may go undetected by conventional diagnostic methods (microscopy and rapid diagnostic tests) and their contribution to malaria transmission varies by transmission settings. This study quantified the burden of subpatent infections from samples collected from three regions of northwest Ethiopia. Methods Sub-samples of dried blood spots from the Ethiopian Malaria Indicator Survey 2015 (EMIS-2015) were tested and compared using microscopy, rapid diagnostic tests (RDTs), and nested polymerase chain reaction (nPCR) to determine the prevalence of subpatent infection. Paired seroprevalence results previously reported along with gender, age, and elevation of residence were explored as risk factors for Plasmodium infection. Results Of the 2608 samples collected, the highest positive rate for Plasmodium infection was found with nPCR 3.3% (95% CI 2.7–4.1) compared with RDT 2.8% (95% CI 2.2–3.5) and microscopy 1.2% (95% CI 0.8–1.7). Of the nPCR positive cases, Plasmodium falciparum accounted for 3.1% (95% CI 2.5–3.8), Plasmodium vivax 0.4% (95% CI 0.2–0.7), mixed P. falciparum and P. vivax 0.1% (95% CI 0.0–0.4), and mixed P. falciparum and Plasmodium malariae 0.1% (95% CI 0.0–0.3). nPCR detected an additional 30 samples that had not been detected by conventional methods. The majority of the nPCR positive cases (61% (53/87)) were from the Benishangul-Gumuz Region. Malaria seropositivity had significant association with nPCR positivity [adjusted OR 10.0 (95% CI 3.2–29.4), P < 0.001]. Conclusion Using nPCR the detection rate of malaria parasites increased by nearly threefold over rates based on microscopy in samples collected during a national cross-sectional survey in 2015 in Ethiopia. Such subpatent infections might contribute to malaria transmission. In addition to strengthening routine surveillance systems, malaria programmes may need to consider low-density, subpatent infections in order to accelerate malaria elimination efforts.
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Affiliation(s)
- Ashenafi Assefa
- Ethiopian Public Health Institute, Arbegnoch Street, Mail Box: 19922, Addis Ababa, Ethiopia. .,School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Ahmed Ali Ahmed
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Wakgari Deressa
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - G Glenn Wilson
- Department of Biology, University of Southern Denmark, 5230, Odense M, Denmark
| | - Amha Kebede
- African Society for Laboratory Medicine, Addis Ababa, Ethiopia
| | - Hussein Mohammed
- Ethiopian Public Health Institute, Arbegnoch Street, Mail Box: 19922, Addis Ababa, Ethiopia
| | - Maruon Sassine
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Mebrahtom Haile
- Disease Prevention and Control Directorate, Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Dereje Dilu
- Disease Prevention and Control Directorate, Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Teka
- U.S. President's Malaria Initiative, United States Agency for International Development, Addis Ababa, Ethiopia
| | - Matthew W Murphy
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, U.S. President's Malaria Initiative, Addis Ababa, Ethiopia
| | - Sheila Sergent
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Zhou Zhiyong
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Brian S Wakeman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - Ya Ping Shi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Jimee Hwang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, U.S. President's Malaria Initiative, Atlanta, GA, USA
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Surendra H, Supargiyono, Ahmad RA, Kusumasari RA, Rahayujati TB, Damayanti SY, Tetteh KKA, Chitnis C, Stresman G, Cook J, Drakeley C. Using health facility-based serological surveillance to predict receptive areas at risk of malaria outbreaks in elimination areas. BMC Med 2020; 18:9. [PMID: 31987052 PMCID: PMC6986103 DOI: 10.1186/s12916-019-1482-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 12/09/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND In order to improve malaria burden estimates in low transmission settings, more sensitive tools and efficient sampling strategies are required. This study evaluated the use of serological measures from repeated health facility-based cross-sectional surveys to investigate Plasmodium falciparum and Plasmodium vivax transmission dynamics in an area nearing elimination in Indonesia. METHODS Quarterly surveys were conducted in eight public health facilities in Kulon Progo District, Indonesia, from May 2017 to April 2018. Demographic data were collected from all clinic patients and their companions, with household coordinates collected using participatory mapping methods. In addition to standard microscopy tests, bead-based serological assays were performed on finger-prick bloodspot samples from 9453 people. Seroconversion rates (SCR, i.e. the proportion of people in the population who are expected to seroconvert per year) were estimated by fitting a simple reversible catalytic model to seroprevalence data. Mixed effects logistic regression was used to examine factors associated with malaria exposure, and spatial analysis was performed to identify areas with clustering of high antibody responses. RESULTS Parasite prevalence by microscopy was extremely low (0.06% (95% confidence interval 0.03-0.14, n = 6) and 0 for P. vivax and P. falciparum, respectively). However, spatial analysis of P. vivax antibody responses identified high-risk areas that were subsequently the site of a P. vivax outbreak in August 2017 (62 cases detected through passive and reactive detection systems). These areas overlapped with P. falciparum high-risk areas and were detected in each survey. General low transmission was confirmed by the SCR estimated from a pool of the four surveys in people aged 15 years old and under (0.020 (95% confidence interval 0.017-0.024) and 0.005 (95% confidence interval 0.003-0.008) for P. vivax and P. falciparum, respectively). The SCR estimates in those over 15 years old were 0.066 (95% confidence interval 0.041-0.105) and 0.032 (95% confidence interval 0.015-0.069) for P. vivax and P. falciparum, respectively. CONCLUSIONS These findings demonstrate the potential use of health facility-based serological surveillance to better identify and target areas still receptive to malaria in an elimination setting. Further implementation research is needed to enable integration of these methods with existing surveillance systems.
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Affiliation(s)
- Henry Surendra
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
- Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Medika, Yogyakarta, 55281 Indonesia
| | - Supargiyono
- Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Medika, Yogyakarta, 55281 Indonesia
- Department of Parasitology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Sekip Utara, Yogyakarta, 55281 Indonesia
| | - Riris A. Ahmad
- Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Medika, Yogyakarta, 55281 Indonesia
- Department of Biostatistics, Epidemiology and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Sekip Utara, Yogyakarta, 55281 Indonesia
| | - Rizqiani A. Kusumasari
- Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Medika, Yogyakarta, 55281 Indonesia
- Department of Parasitology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Sekip Utara, Yogyakarta, 55281 Indonesia
| | | | - Siska Y. Damayanti
- District Health Office of Kulon Progo, Jln. Suparman No 1, Wates, 55611 Indonesia
| | - Kevin K. A. Tetteh
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
| | | | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
| | - Jackie Cook
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
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Wangchuk S, Gyeltshen S, Dorji K, Wangdi T, Dukpa T, Namgay R, Dorjee S, Tobgay T, Chaijaroenkul W, Na-Bangchang K. Malaria elimination in Bhutan: asymptomatic malaria cases in the Bhutanese population living in malaria-risk areas and in migrant workers from India. Rev Inst Med Trop Sao Paulo 2019; 61:e52. [PMID: 31531630 PMCID: PMC6746194 DOI: 10.1590/s1678-9946201961052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 07/31/2019] [Indexed: 11/28/2022] Open
Abstract
In 2018, Bhutan reported 54 cases of malaria, of which six were indigenous, 14 introduced and 34 imported. Considering the continuous reduction in the number of indigenous cases, Bhutan plans to eliminate malaria by 2025 under the Bhutan Malaria Elimination Strategy. The study was conducted to assess the presence of asymptomatic plasmodial infection in both, Bhutanese population living in malaria-risk areas and in migrant workers to guide the elimination strategies. A cross-sectional study was conducted from April to May 2016 in 750 Bhutanese people and 473 migrant workers. Plasmodium falciparum and Plasmodium vivax infections were investigated by using a rapid diagnostic test (RDT) and the polymerase chain reaction (PCR). Prevalence of asymptomatic plasmodial infection based on PCR was 0.27% (95% CI: 0.05–1.07%) among Bhutanese people with a mean age of 43 years old. The proportions of males and females were 45% and 55%, respectively. Among migrant workers, the prevalence of asymptomatic plasmodial infection was 0.42% (95% CI: 0.07–1.69%) with a mean age of 30 years old. The majority of migrant workers were from the neighboring Indian State of West Bengal (57.51%), followed by Assam (12.26%). RDT in both study groups did not detect any plasmodial infection. The presence of a low prevalence of asymptomatic plasmodial infection indicates that the current elimination strategies and interventions are effective.
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Affiliation(s)
- Sonam Wangchuk
- Bhutan Ministry of Health, Royal Center for Disease Control, Thimphu, Bhutan
| | - Sonam Gyeltshen
- Bhutan Ministry of Health, Royal Center for Disease Control, Thimphu, Bhutan
| | - Kunzang Dorji
- Bhutan Ministry of Health, Royal Center for Disease Control, Thimphu, Bhutan
| | - Tenzin Wangdi
- Bhutan Ministry of Health, Department of Public Health, Vector Borne Disease Control Programme, Thimphu, Bhutan
| | - Tobgyel Dukpa
- Bhutan Ministry of Health, Department of Public Health, Vector Borne Disease Control Programme, Thimphu, Bhutan
| | - Rinzin Namgay
- Bhutan Ministry of Health, Department of Public Health, Vector Borne Disease Control Programme, Thimphu, Bhutan
| | - Sithar Dorjee
- Bhutan Agriculture and Food Regulatory Authority, Thimphu, Bhutan.,Khesar Gyalpo University of Medical Science, Thimphu, Bhutan
| | - Tashi Tobgay
- Khesar Gyalpo University of Medical Science, Thimphu, Bhutan
| | - Wanna Chaijaroenkul
- Thammasat University, Cholangiocarcinoma, Chulabhorn International College of Medicine, Center of Excellence in Pharmacology and Molecular Biology of Malaria, Pathumthani, Thailand
| | - Kesara Na-Bangchang
- Thammasat University, Cholangiocarcinoma, Chulabhorn International College of Medicine, Center of Excellence in Pharmacology and Molecular Biology of Malaria, Pathumthani, Thailand
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Haanshuus CG, Mørch K, Blomberg B, Strøm GEA, Langeland N, Hanevik K, Mohn SC. Assessment of malaria real-time PCR methods and application with focus on low-level parasitaemia. PLoS One 2019; 14:e0218982. [PMID: 31276473 PMCID: PMC6611585 DOI: 10.1371/journal.pone.0218982] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 06/04/2019] [Indexed: 01/04/2023] Open
Abstract
In epidemiological surveys and surveillance the application of molecular tools is essential in detecting submicroscopic malaria. A genus-specific conventional cytochrome b (cytb) PCR has shown high sensitivity in field studies, detecting 70% submicroscopic malaria. The main objective of this study was to assess the conversion from conventional to real-time PCR testing both SYBR and probe protocols, and including quantitative (q) PCR. The protocols were assessed applying well-defined clinical patient material consisting of 33 positive and 80 negative samples. Sequencing of positive PCR products was performed. In addition, a sensitivity comparison of real-time PCR methods was done by including five relevant assays investigating the effect of amplification target and platform. Sensitivity was further examined using field material consisting of 111 P.falciparum positive samples from Tanzanian children (< 5 years), as well as using related patient data to assess the application of q-PCR with focus on low-level parasitaemia. Both the cytb SYBR and probe PCR protocols showed as high sensitivity and specificity as their conventional counterpart, except missing one P. malariae sample. The SYBR protocol was more sensitive and specific than using probe. Overall, choice of amplification target applied is relevant for achieving ultra-sensitivity, and using intercalating fluorescence dye rather than labelled hydrolysis probes is favourable. Application of q-PCR analysis in field projects is important for the awareness and understanding of low-level parasitaemia. For use in clinical diagnosis and epidemiological studies the highly sensitive and user-friendly cytb SYBR q-PCR method is a relevant tool. The genus-specific method has the advantage that species identification by sequencing can be performed as an alternative to species-specific PCR.
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Affiliation(s)
- Christel Gill Haanshuus
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- * E-mail:
| | - Kristine Mørch
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Bjørn Blomberg
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Nina Langeland
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Haraldsplass Deaconess Hospital, Bergen, Norway
| | - Kurt Hanevik
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Stein Christian Mohn
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
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Koumba Lengongo JV, M'Bondoukwé NP, Ndong Ngomo JM, François S, Ndjoyi-Mbiguino A, Mbang Nguema OA, Bouyou Akotet MK, Mawili-Mboumba DP. Submicroscopic Plasmodium falciparum parasitaemia in human immunodeficiency virus-infected adults living in Gabon (Central Africa)-a pilot study. Trans R Soc Trop Med Hyg 2019; 112:103-108. [PMID: 29660103 DOI: 10.1093/trstmh/try029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/16/2018] [Indexed: 01/22/2023] Open
Abstract
Background Submicroscopic malaria infections contribute to malaria transmission. Describing the extent of the parasite reservoir is of importance. In people living with human immunodeficiency virus (HIV), the frequency of subpatent malaria infections is rarely reported. The aim of the present study was to determine the frequency of submicroscopic infections in people living with HIV in Gabon and its relationship with cotrimoxazole (CTX) use. Methods A survey was conducted in two health care centres in rural areas (Koulamoutou and Oyem) and three in urban areas (Libreville) of Gabon from March 2015 to June 2016. Blood samples were collected from consenting people living with HIV with a negative blood smear. Information on CTX and antiretroviral therapy intake was recorded from the medical file of the patient and through an interview. For molecular analysis, the Plasmodium small subunit ribosomal RNA gene was amplified by nested polymerase chain reaction. Results Submicroscopic infections were detected in 10.1% (n=12/119) of the people living with HIV, more frequently in those residing in rural areas (15.1%) compared with urban areas (2.1%) (p<0.01). The proportion of anaemic patients was 1.74-fold more frequent in malaria-infected patients, although not statistically significant. Submicroscopic infections frequency did not vary according to CTX intake (p=0.6). Conclusions The present pilot study highlights a non-negligible frequency of submicroscopic malaria infections in people living with HIV from rural areas, but no relationship with CTX intake was found.
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Affiliation(s)
- J V Koumba Lengongo
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - N P M'Bondoukwé
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - J M Ndong Ngomo
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - S François
- Department of Bacteriology-Virology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - A Ndjoyi-Mbiguino
- Department of Bacteriology-Virology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - O A Mbang Nguema
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - M K Bouyou Akotet
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
| | - D P Mawili-Mboumba
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences, BP 4009, Libreville, Gabon
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Getachew D, Gebre-Michael T, Balkew M, Tekie H. Species composition, blood meal hosts and Plasmodium infection rates of Anopheles mosquitoes in Ghibe River Basin, southwestern Ethiopia. Parasit Vectors 2019; 12:257. [PMID: 31122286 PMCID: PMC6533711 DOI: 10.1186/s13071-019-3499-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 05/09/2019] [Indexed: 01/25/2023] Open
Abstract
Background Vector control interventions using long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are commonly practiced tools for the control of malaria in Ethiopia. In order to evaluate the effectiveness of these control interventions, and understand the prevailing malaria vectors, their incrimination in disease transmission, and their resting and feeding behavior, we set out to identify the Anopheles species, their blood meal sources, and entomological inoculation rate (EIR) in Ghibe and Darge within the Ghibe River basin, southwestern Ethiopia. Methods Adult Anopheles mosquitoes were sampled both indoors and outdoors from January 2015 to October 2016 using Centers for Disease Control and Prevention (CDC) light traps, pyrethrum spray catch (PSC), artificial pit shelters and mouth aspirators. Mosquito species were morphologically identified, and their blood meal sources and malaria sporozoite rates were assessed using enzyme-linked immunosorbent assays. Results In total, 13 species of Anopheles mosquitoes were identified, among which Anopheles gambiae (s.l.) was the predominant species: 87.9 and 67.7% in Ghibe and Darge, respectively. The mean density of An. gambiae (s.l.) collected per night using CDC light traps was 1.8 and 0.7 outdoors and indoors, respectively, in Ghibe, and 0.125 and 0.07 indoors and outdoors, respectively, in Darge. Anopheles mosquito abundance was higher in houses near the river than in houses far from the river in both study sites. Among Anopheles mosquitoes sampled using CDC light trap catches, 67.6% were unfed and the indoor and outdoor human blood indices of An. gambiae (s.l.) were 58.4 and 15.8%, respectively in Ghibe, while in Darge, they were 57.1 and 50%, respectively. Sporozoite rates were 0.07% for P. vivax and 0.07% for P. falciparum in Ghibe and zero in Darge. In Ghibe, the overall EIRs for P. falciparum and P. vivax were zero and 8.4 infective bites/person/year, respectively, in 2015, while zero and 5.4 infective bites/person/year for P. vivax and P. falciparum, respectively, in 2016. No Plasmodium-positive Anopheles mosquitoes were identified from Darge. Conclusions Anopheles gambiae (s.l.), the principal vector of malaria in Ethiopia was the most abundant species both indoors and outdoors, fed both on human and cattle blood and occurred at higher frequencies near rivers. Anopheles gambiae (s.l.) that were circumsporozoite-positive for Plasmodium species were collected from Ghibe, but not Darge.
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Affiliation(s)
- Dejene Getachew
- Department of Biology, Dire Dawa University, P. O. Box 1362, Dire Dawa, Ethiopia. .,Department of Zoological Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
| | - Teshome Gebre-Michael
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
| | - Meshesha Balkew
- Abt Associates, PMI VectorLink Ethiopia Project, Addis Ababa, Ethiopia
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
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Low genetic diversity and complexity of submicroscopic Plasmodium falciparum infections among febrile patients in low transmission areas in Senegal. PLoS One 2019; 14:e0215755. [PMID: 31022221 PMCID: PMC6483351 DOI: 10.1371/journal.pone.0215755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 04/08/2019] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Submicroscopic Plasmodium infections are common in malaria endemic countries, but very little studies have been done in Senegal. This study investigates the genetic diversity and complexity of submicroscopic P. falciparum infections among febrile patients in low transmission areas in Senegal. MATERIALS AND METHODS Hundred and fifty blood samples were collected from febrile individuals living in Dielmo and Ndiop (Senegal) between August 2014 and January 2015, tested for microscopic and sub-microscopic P. falciparum infections and characterized for their genetic diversity and complexity of infections using msp-1 and msp-2 genotyping. RESULTS Submicroscopic P. falciparum infections were 19.6% and 25% in Dielmo and Ndiop, respectively. K1 and 3D7 were the predominant msp-1 and msp-2 allelic types with respective frequencies of 67.36% and 67.10% in microscopic isolates and 58.24% and 78% in submicroscopic ones. Frequencies of msp-1 allelic types were statistically comparable between the studied groups (p>0.05), and were respectively 93.54% vs 87.5% for K1, 60% vs 54.83% for MAD20 and 41.93% vs 22.5% for RO33 while frequencies of msp-2 allelic types were significantly highest in the microscopy group for FC27 (41.93% vs 10%, Fisher's Exact Test, p = 0.001) and 3D7 (61.29% vs 32.5%, Fisher's Exact Test, p = 0.02). Multiplicities of infection were lowest in submicroscopic P. falciparum isolates. CONCLUSIONS The study revealed a high submicroscopic P. falciparum carriage among patients in the study areas, and that submicroscopic P. falciparum isolates had a lower genetic diversity and complexity of malaria infections.
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McCreesh P, Mumbengegwi D, Roberts K, Tambo M, Smith J, Whittemore B, Kelly G, Moe C, Murphy M, Chisenga M, Greenhouse B, Ntuku H, Kleinschmidt I, Sturrock H, Uusiku P, Gosling R, Bennett A, Hsiang MS. Subpatent malaria in a low transmission African setting: a cross-sectional study using rapid diagnostic testing (RDT) and loop-mediated isothermal amplification (LAMP) from Zambezi region, Namibia. Malar J 2018; 17:480. [PMID: 30567537 PMCID: PMC6299963 DOI: 10.1186/s12936-018-2626-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/11/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Subpatent malaria infections, or low-density infections below the detection threshold of microscopy or standard rapid diagnostic testing (RDT), can perpetuate persistent transmission and, therefore, may be a barrier for countries like Namibia that are pursuing malaria elimination. This potential burden in Namibia has not been well characterized. METHODS Using a two-stage cluster sampling, cross-sectional design, subjects of all age were enrolled during the end of the 2015 malaria transmission season in Zambezi region, located in northeast Namibia. Malaria RDTs were performed with subsequent gold standard testing by loop-mediated isothermal amplification (LAMP) using dried blood spots. Infection prevalence was measured and the diagnostic accuracy of RDT calculated. Relationships between recent fever, demographics, epidemiological factors, and infection were assessed. RESULTS Prevalence of Plasmodium falciparum malaria infection was low: 0.8% (16/1919) by RDT and 2.2% (43/1919) by LAMP. All but one LAMP-positive infection was RDT-negative. Using LAMP as gold standard, the sensitivity and specificity of RDT were 2.3% and 99.2%, respectively. Compared to LAMP-negative infections, a higher portion LAMP-positive infections were associated with fever (45.2% vs. 30.4%, p = 0.04), though 55% of infections were not associated with fever. Agricultural occupations and cattle herding were significantly associated with LAMP-detectable infection (Adjusted ORs 5.02, 95% CI 1.77-14.23, and 11.82, 95% CI 1.06-131.81, respectively), while gender, travel, bed net use, and indoor residual spray coverage were not. CONCLUSIONS This study presents results from the first large-scale malaria cross-sectional survey from Namibia using molecular testing to characterize subpatent infections. Findings suggest that fever history and standard RDTs are not useful to address this burden. Achievement of malaria elimination may require active case detection using more sensitive point-of-care diagnostics or presumptive treatment and targeted to high-risk groups.
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Affiliation(s)
- Patrick McCreesh
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Davis Mumbengegwi
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Kathryn Roberts
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Munyaradzi Tambo
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Jennifer Smith
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Brooke Whittemore
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gerard Kelly
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Caitlin Moe
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Max Murphy
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, UCSF, San Francisco, CA, USA
| | - Mukosha Chisenga
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Bryan Greenhouse
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, UCSF, San Francisco, CA, USA
| | - Henry Ntuku
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Immo Kleinschmidt
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Wits Research Institute for Malaria, University of Witwatersrands, Johannesburg, South Africa
| | - Hugh Sturrock
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Petrina Uusiku
- National Vectorborne Disease Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Roland Gosling
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA. .,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Pediatrics, UCSF Benioff Children's Hospital, San Francisco, CA, USA.
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Assefa A, Ali A, Deressa W, Tsegaye W, Abebe G, Sime H, Kebede A, Jima D, Kassa M, Abreha T, Teka H, Solomon H, Malone J, Shi YP, Zhou Z, Reithinger R, Hwang J. Glucose-6-phosphate dehydrogenase (G6PD) deficiency in Ethiopia: absence of common African and Mediterranean allelic variants in a nationwide study. Malar J 2018; 17:388. [PMID: 30367627 PMCID: PMC6204031 DOI: 10.1186/s12936-018-2538-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/20/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Building on the declining trend of malaria in Ethiopia, the Federal Ministry of Health aims to eliminate malaria by 2030. As Plasmodium falciparum and Plasmodium vivax are co-endemic in Ethiopia, the use of primaquine is indicated for both transmission interruption and radical cure, respectively. However, the limited knowledge of the local prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and its associated variants has hindered the use of primaquine. METHODS Some 11,138 dried blood spot (DBS) samples were collected in 2011 as part of a national, household Malaria Indicator Survey, a multi-stage nationally representative survey of all malaria-endemic areas of Ethiopia. A randomly selected sub-set of 1414 DBS samples was successfully genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Considering the geographical position and ethnic mix of the country, three common variants: G6PD*A (A376G), G6PD*A- (G202A) and Mediterranean (C563T) were investigated. RESULTS Of the 1998 randomly selected individuals, 1429 (71.5%) DBS samples were genotyped and merged to the database, of which 53.5% were from females. G6PD*A (A376G) was the only genotype detected. No sample was positive for either G6PD*A- (G202A) or Mediterranean (C563T) variants. The prevalence of G6PD*A (A376G) was 8.9% [95% confidence interval (CI) 6.7-11.2] ranging from 12.2% in the Southern Nations, Nationalities and Peoples' (95% CI 5.7-18.7) to none in Dire Dawa/Harari Region. CONCLUSION The common G6PD*A- (G202A) or Mediterranean (C563T) variants were not observed in this nationwide study. The observed G6PD*A (A376G) mutation has little or no clinical significance. These findings supported the adoption of primaquine for P. falciparum transmission interruption and radical cure of P. vivax in Ethiopia. As the presence of other clinically important, less common variants cannot be ruled out, the implementation of radical cure will be accompanied by active haematological and adverse events monitoring in Ethiopia.
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Affiliation(s)
- Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia. .,Addis Ababa University, Addis Ababa, Ethiopia.
| | - Ahmed Ali
- Addis Ababa University, Addis Ababa, Ethiopia
| | | | | | | | - Heven Sime
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Amha Kebede
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Daddi Jima
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Moges Kassa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Hiwot Teka
- US President's Malaria Initiative, United States Agency for International Development, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Joseph Malone
- US President's Malaria Initiative, Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ya Ping Shi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Zhiyong Zhou
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Richard Reithinger
- US President's Malaria Initiative, United States Agency for International Development, Addis Ababa, Ethiopia.,RTI International, Washington, DC, USA
| | - Jimee Hwang
- US President's Malaria Initiative, Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Global Health Group, University of California San Francisco, San Francisco, CA, USA
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Zemene E, Koepfli C, Tiruneh A, Yeshiwondim AK, Seyoum D, Lee MC, Yan G, Yewhalaw D. Detection of foci of residual malaria transmission through reactive case detection in Ethiopia. Malar J 2018; 17:390. [PMID: 30367636 PMCID: PMC6203988 DOI: 10.1186/s12936-018-2537-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/20/2018] [Indexed: 12/18/2022] Open
Abstract
Background Sub-microscopic and asymptomatic infections could be bottlenecks to malaria elimination efforts in Ethiopia. This study determined the prevalence of malaria, and individual and household-level factors associated with Plasmodium infections obtained following detection of index cases in health facilities in Jimma Zone. Methods Index malaria cases were passively detected and tracked in health facilities from June to November 2016. Moreover, family members of the index houses and neighbours located within approximately 200 m from the index houses were also screened for malaria. Results A total of 39 index cases initiated the reactive case detection of 726 individuals in 116 households. Overall, the prevalence of malaria using microscopy and PCR was 4.0% and 8.96%, respectively. Seventeen (43.6%) of the index cases were from Doyo Yaya kebele, where parasite prevalence was higher. The majority of the malaria cases (90.74%) were asymptomatic. Fever (AOR = 12.68, 95% CI 3.34–48.18) and history of malaria in the preceding 1 year (AOR = 3.62, 95% CI 1.77–7.38) were significant individual-level factors associated with detection of Plasmodium infection. Moreover, living in index house (AOR = 2.22, 95% CI 1.16–4.27), house with eave (AOR = 2.28, 95% CI 1.14–4.55), area of residence (AOR = 6.81, 95% CI 2.49–18.63) and family size (AOR = 3.35, 95% CI 1.53–7.33) were main household-level predictors for residual malaria transmission. Conclusion The number of index cases per kebele may enhance RACD efforts to detect additional malaria cases in low transmission settings. Asymptomatic and sub-microscopic infections were high in the study area, which need new or improved surveillance tools for malaria elimination efforts.
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Affiliation(s)
- Endalew Zemene
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia.
| | - Cristian Koepfli
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
| | - Abebaw Tiruneh
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia
| | | | - Dinberu Seyoum
- Department of Statistics, College of Natural Sciences, Jimma University, Jimma, Ethiopia
| | - Ming-Chieh Lee
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia.,Tropical and Infectious Diseases Research Centre, Jimma University, Jimma, Ethiopia
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Kießling N, Brintrup J, Zeynudin A, Abduselam N, Götz S, Mack M, Pritsch M, Wieser A, Kohne E, Berens-Riha N. Glucose-6-phosphate dehydrogenase activity measured by spectrophotometry and associated genetic variants from the Oromiya zone, Ethiopia. Malar J 2018; 17:358. [PMID: 30314477 PMCID: PMC6186078 DOI: 10.1186/s12936-018-2510-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The study aimed to gain first data on the prevalence of G6PD enzyme deficiency measured by spectrophotometry and associated genetic variants in Jimma and surroundings, Ethiopia. The area is a Plasmodium vivax endemic region, but 8-aminoquinolines such as primaquine are not recommended as G6PD testing is not available. METHODS Healthy volunteers were recruited at Jimma University, Ethiopia. Enzyme activity was tested by spectrophotometry at the University of Ulm, Germany. A G6PD RDT (Binax NOW® G6PD, Alere, USA) was additionally performed. The G6PD gene was analysed for polymorphisms in a sub-population. Tests for haemoglobinopathies and the presence of malaria parasites were conducted. RESULTS No severe or moderate (cut-off 60%) G6PD deficiency was found in 206 volunteers. Median male activity was 6.1 U/g Hb. Eleven participants (5.4%) showed activities between 70 and 80%. No haemoglobinopathy was detected. None of the subjects showed asymptomatic parasitaemia. One G6PD-A+ variant (A376G) and one new non-synonymous mutation (G445A) were found. CONCLUSIONS As the prevalence of G6PD deficiency seems low in this area, the use of 8-aminoquinolines should be encouraged. However, reliable G6PD testing methods have to be implemented and safe cut-off levels need to be defined.
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Affiliation(s)
- Nora Kießling
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Leopoldstrasse 5, 80802, Munich, Germany
| | - Joaquin Brintrup
- Hemoglobin Laboratory, Department of Pediatrics, University Hospital Ulm, Eythstrasse 24, 89075, Ulm, Germany
| | - Ahmed Zeynudin
- Department of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Nuredin Abduselam
- Department of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Sylvia Götz
- Hemoglobin Laboratory, Department of Pediatrics, University Hospital Ulm, Eythstrasse 24, 89075, Ulm, Germany
| | - Margith Mack
- Hemoglobin Laboratory, Department of Pediatrics, University Hospital Ulm, Eythstrasse 24, 89075, Ulm, Germany
| | - Michael Pritsch
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Leopoldstrasse 5, 80802, Munich, Germany.,German Centre for Infection Research (DZIF) at LMU, Munich, Germany
| | - Andreas Wieser
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Leopoldstrasse 5, 80802, Munich, Germany.,Department of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia.,German Centre for Infection Research (DZIF) at LMU, Munich, Germany
| | - Elisabeth Kohne
- Hemoglobin Laboratory, Department of Pediatrics, University Hospital Ulm, Eythstrasse 24, 89075, Ulm, Germany
| | - Nicole Berens-Riha
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Leopoldstrasse 5, 80802, Munich, Germany. .,German Centre for Infection Research (DZIF) at LMU, Munich, Germany.
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Kondrashin AV, Morozova LF, Stepanova EV, Turbabina NA, Maksimova MS, Morozov EN. On the epidemiology of Plasmodium vivax malaria: past and present with special reference to the former USSR. Malar J 2018; 17:346. [PMID: 30286752 PMCID: PMC6172834 DOI: 10.1186/s12936-018-2495-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 09/28/2018] [Indexed: 12/27/2022] Open
Abstract
Presently, many malaria-endemic countries in the world are transitioning towards malaria elimination. Out of the 105 countries with ongoing malaria transmission, 10 countries are classified as being in the pre-elimination phase of malaria control, and 9 countries are in the malaria elimination stage, whereas 7 countries are classified as being in the prevention of introduction phase. Between 2000 and 2015, 17 countries eliminated malaria (i.e., attained zero indigenous cases for 3 years or more). Seven countries were certified by the WHO as having successfully eliminated malaria. The purpose of this review was to analyse the epidemiological characteristics of vivax malaria during the various stages of malaria eradication (elimination) programmes in different countries in the past and present. Experiences of the republics of the former USSR with malaria are interesting, particularly since the data overwhelmingly were published in Russian and might not be known to western readers. Among the most important characteristics of Plasmodium vivax epidemiology at present are changes in the ratio of the short-incubation P. vivax to long-incubation P. vivax, the incidence of severe P. vivax cases, the increased numbers of asymptomatic P. vivax cases, the reduced response to anti-malarials and a few others. Various factors contributing towards the peculiarities of P. vivax epidemiology are discussed.
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Affiliation(s)
| | | | | | | | | | - Evgeny N Morozov
- Sechenov University, Moscow, Russian Federation.
- Department of Tropical, Parasitic Diseases and Disinfectology, Russian Medical Academy of Continuous Professional Education, Moscow, Russian Federation.
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Tseghereda YG, Nganga JK, Kimang'a AN, Mehari TH, Weldemichael YG. Glucose-6-phosphate dehydrogenase deficiency allelic variants and their prevalence in malaria patients in Eritrea. Pan Afr Med J 2018; 31:46. [PMID: 30918572 PMCID: PMC6430948 DOI: 10.11604/pamj.2018.31.46.16527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/31/2018] [Indexed: 11/23/2022] Open
Abstract
Introduction Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy with a relatively high frequency in malaria-endemic regions. In Eritrea, there is scanty knowledge of G6PD deficiency. The aim of the study was to characterize and determine the prevalence of four common G6PD allelic variants. Methods Three hundred and fourteen dried blood spot samples from unrelated microscopically diagnosed malaria patient Eritrean ethnic groups living in five zobas (regions) of Eritrea were analysed by PCR-RFLP method to identify the G6PD B, G6PD A (A376G), G6PD A-(G202A), and G6PD Mediterranean (C563T) variants. To confirm the RFLP results, samples positive for A376G but negative for G202A variants were subjected to Sanger sequencing and a subset of PCR products (exon 5) directly sequenced to identify A376G and other mutations. Results For G6PD genotyping, G6PD B was detected in 87.5% and A376G detected in 12.5% of malaria patients, whereas G202A and C563T were absent. Bivariate Statistical analysis showed a statistically significant association between G6PD genotypes and zoba (P < 0.004 < 0.05). Sequencing revealed the expected A376G variant. In exon 5, four common (A376G) mutations, three uncommon mutations rs782669677 (535G→A) and one potentially new mutation (451G→C), relative to the reference, mRNA NM_001042351 were detected. Bioinformatic analysis of these mutations' potential functional impact suggests minimal effect on protein function. Conclusion This is the first report indicating that G6PD B and G6PD A genotypes are prevalent in Eritrea. Similar findings were reported in neighboring countries. Further studies including phenotype analysis are needed to corroborate the observed results.
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Low and heterogeneous prevalence of glucose-6-phosphate dehydrogenase deficiency in different settings in Ethiopia using phenotyping and genotyping approaches. Malar J 2018; 17:281. [PMID: 30071859 PMCID: PMC6071387 DOI: 10.1186/s12936-018-2437-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 07/30/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND 8-Aminoquinolines such as primaquine clear mature Plasmodium falciparum gametocytes that are responsible for transmission from human to mosquitoes and bring radical cure in Plasmodium vivax by clearing dormant liver stages. Deployment of primaquine is thus of relevance for malaria elimination efforts but challenged by the widespread prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PDd) in endemic countries since primaquine in G6PDd individuals may lead to acute haemolysis. In this study, the prevalence of G6PDd was investigated in different settings in Ethiopia using phenotyping and genotyping approaches. METHODS Community and school based cross-sectional surveys were conducted from October to December 2016 in four administrative regions (Gambela, Benishangul Gumuz, Oromia, and Amhara) in Ethiopia. Finger prick blood samples were collected for G6PD enzyme activity using the CareStart™ G6PD screening test and genotyping of 36 selected single nucleotide polymorphisms (SNPs) located in the G6PD gene and its flanking regions. RESULTS Overall, the prevalence of phenotypic G6PDd was 1.4% (22/1609). For the first time in the Ethiopian population, the African variant (A-) was detected in 3.5% (7/199) of the limited set of genotyped samples, which were all phenotypically normal. Interestingly, all of these individuals had a variation at the rs2515904 locus. Strong geographical variation was observed for both phenotypic and genotypic G6PDd; three-quarters of the phenotypically G6PDd individuals were detected in Gambela. CONCLUSION A very low prevalence of G6PDd was detected in the present study populations. The presence of the A- variant alongside other G6PD mutants and the patchy distribution of G6PDd indicate that larger studies specifically designed to unravel the distribution of G6PDd at small geographical scale may be needed to tailor malaria elimination efforts in Ethiopia to the local context.
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Recht J, Ashley EA, White NJ. Use of primaquine and glucose-6-phosphate dehydrogenase deficiency testing: Divergent policies and practices in malaria endemic countries. PLoS Negl Trop Dis 2018; 12:e0006230. [PMID: 29672516 PMCID: PMC5908060 DOI: 10.1371/journal.pntd.0006230] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Primaquine is the only available antimalarial drug that kills dormant liver stages of Plasmodium vivax and Plasmodium ovale malarias and therefore prevents their relapse (‘radical cure’). It is also the only generally available antimalarial that rapidly sterilises mature P. falciparum gametocytes. Radical cure requires extended courses of primaquine (usually 14 days; total dose 3.5–7 mg/kg), whereas transmissibility reduction in falciparum malaria requires a single dose (formerly 0.75 mg/kg, now a single low dose [SLD] of 0.25 mg/kg is recommended). The main adverse effect of primaquine is dose-dependent haemolysis in glucose 6-phosphate dehydrogenase (G6PD) deficiency, the most common human enzymopathy. X-linked mutations conferring varying degrees of G6PD deficiency are prevalent throughout malaria-endemic regions. Phenotypic screening tests usually detect <30% of normal G6PD activity, identifying nearly all male hemizygotes and female homozygotes and some heterozygotes. Unfortunately, G6PD deficiency screening is usually unavailable at point of care, and, as a consequence, radical cure is greatly underused. Both haemolytic risk (determined by the prevalence and severity of G6PD deficiency polymorphisms) and relapse rates vary, so there has been considerable uncertainty in both policies and practices related to G6PD deficiency testing and use of primaquine for radical cure. Review of available information on the prevalence and severity of G6PD variants together with countries’ policies for the use of primaquine and G6PD deficiency testing confirms a wide range of practices. There remains lack of consensus on the requirement for G6PD deficiency testing before prescribing primaquine radical cure regimens. Despite substantially lower haemolytic risks, implementation of SLD primaquine as a P. falciparum gametocytocide also varies. In Africa, a few countries have recently adopted SLD primaquine, yet many with areas of low seasonal transmission do not use primaquine as an antimalarial at all. Most countries that recommended the higher 0.75 mg/kg single primaquine dose for falciparum malaria (e.g., most countries in the Americas) have not changed their recommendation. Some vivax malaria–endemic countries where G6PD deficiency testing is generally unavailable have adopted the once-weekly radical cure regimen (0.75 mg/kg/week for 8 weeks), known to be safer in less severe G6PD deficiency variants. There is substantial room for improvement in radical cure policies and practices.
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Affiliation(s)
- Judith Recht
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Elizabeth A. Ashley
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
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Ding G, Zhu G, Cao C, Miao P, Cao Y, Wang W, Gu Y, Xu S, Wang S, Zhou H, Cao J. The challenge of maintaining microscopist capacity at basic levels for malaria elimination in Jiangsu Province, China. BMC Public Health 2018; 18:489. [PMID: 29650008 PMCID: PMC5898017 DOI: 10.1186/s12889-018-5307-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 03/13/2018] [Indexed: 12/21/2022] Open
Abstract
Background Local malaria transmission has decreased rapidly since the National Malaria Elimination Action Plan was launched in China in 2010. However, imported malaria cases from Africa and Southeast Asia still occur in China due to overseas laborers. Diagnosis by microscopy is the gold standard for malaria and is used in most hospitals in China. However, the current capacity of microscopists to manage malaria cases in hospitals and public health facilities to meet the surveillance needs to eliminate and prevent the reintroduction of malaria is unknown. Methods Malaria diagnoses were assessed by comparing the percentage of first visit and confirmed malaria diagnoses at Centers for Disease Control and Prevention (CDCs) and hospitals. The basic personnel information for public health departments and hospitals at different levels was investigated. The skills of microscopists for blood smear preparation and slide interpretation were also examined at the county and township levels. Results Inaccurate rate with 13.49% and 7.32%, respectively, in 2013 and 2014, from 341 and 355 reported cases from sub-provincial levels in Jiangsu province. Most of the 523 malaria cases reported in Nantong Prefecture from 2000 to 2014 involved patients who first visited county CDCs seeking treatment, however, none of these cases received confirmed diagnosis of malaria in townships or villages.The staff at county CDCs and hospitals with a higher education background performed better at making and interpreting blood smears than staff from townships. Conclusions The network for malaria elimination in an entire province has been well established. However, an insufficient capacity for malaria diagnosis was observed, especially the preparing and reading the blood smears at the township and village levels, which is a challenge to achieving and maintaining malaria elimination.
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Affiliation(s)
- Guisheng Ding
- Nantong Center for Diseases Control and Prevention, Nantong, Jiangsu Province, People's Republic of China
| | - Guoding Zhu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China
| | - Caiqun Cao
- Nantong Center for Diseases Control and Prevention, Nantong, Jiangsu Province, People's Republic of China
| | - Ping Miao
- Rudong Center for Diseases Control and Prevention, Nantong, Jiangsu Province, People's Republic of China
| | - Yuanyuan Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China
| | - Weiming Wang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China
| | - Yaping Gu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China
| | - Sui Xu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China
| | - Shengqiang Wang
- Wuxi Enter-Exit Inspection and Quarantine Bureau, Jiangsu Province, People's Republic of China
| | - Huayun Zhou
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China.
| | - Jun Cao
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China. .,Public Health Research Center, Jiangnan University, Wuxi, People's Republic of China.
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Saito T, Kikuchi A, Kaneko A, Isozumi R, Teramoto I, Kimura M, Hirasawa N, Hiratsuka M. Rapid and sensitive multiplex single-tube nested PCR for the identification of five human Plasmodium species. Parasitol Int 2018; 67:277-283. [PMID: 29374580 DOI: 10.1016/j.parint.2018.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/11/2018] [Accepted: 01/23/2018] [Indexed: 10/18/2022]
Abstract
Malaria is caused by five species of Plasmodium in humans. Microscopy is currently used for pathogen detection, requiring considerable training and technical expertise as the parasites are often difficult to differentiate morphologically. Rapid diagnostic tests are as reliable as microscopy and offer faster diagnoses but possess lower detection limits and are incapable of distinguishing among the parasitic species. To improve global health efforts towards malaria control, a rapid, sensitive, species-specific, and economically viable diagnostic method is needed. In this study, we designed a malaria diagnostic method involving a multiplex single-tube nested PCR targeting Plasmodium mitochondrial cytochrome c oxidase III and single-stranded tag hybridization chromatographic printed-array strip. The detection sensitivity was found to be at least 40 times higher than that of agarose gel electrophoresis with ethidium bromide. This system also enables the identification of both single- and mixed-species malaria infections. The assay was validated with 152 Kenyan samples; using nested PCR as the standard, the assay's sensitivity and specificity were 88.7% and 100.0%, respectively. The turnaround time required, from PCR preparation to signal detection, is 90min. Our method should improve the diagnostic speed, treatment efficacy, and control of malaria, in addition to facilitating surveillance within global malaria eradication programs.
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Affiliation(s)
- Takahiro Saito
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Aoi Kikuchi
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Akira Kaneko
- Department of Parasitology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan
| | - Rie Isozumi
- Department of Parasitology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan
| | - Isao Teramoto
- Department of Parasitology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan
| | - Masatsugu Kimura
- Radioisotope Centre, Graduate School of Medicine, Osaka City University, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan; Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai 980-8574, Japan; Tohoku Medical Megabank Organization, Tohoku University, Sendai 980-8575, Japan.
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Medzihradsky OF, Kleinschmidt I, Mumbengegwi D, Roberts KW, McCreesh P, Dufour MSK, Uusiku P, Katokele S, Bennett A, Smith J, Sturrock H, Prach LM, Ntuku H, Tambo M, Didier B, Greenhouse B, Gani Z, Aerts A, Gosling R, Hsiang MS. Study protocol for a cluster randomised controlled factorial design trial to assess the effectiveness and feasibility of reactive focal mass drug administration and vector control to reduce malaria transmission in the low endemic setting of Namibia. BMJ Open 2018; 8:e019294. [PMID: 29374672 PMCID: PMC5829876 DOI: 10.1136/bmjopen-2017-019294] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION To interrupt malaria transmission, strategies must target the parasite reservoir in both humans and mosquitos. Testing of community members linked to an index case, termed reactive case detection (RACD), is commonly implemented in low transmission areas, though its impact may be limited by the sensitivity of current diagnostics. Indoor residual spraying (IRS) before malaria season is a cornerstone of vector control efforts. Despite their implementation in Namibia, a country approaching elimination, these methods have been met with recent plateaus in transmission reduction. This study evaluates the effectiveness and feasibility of two new targeted strategies, reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in Namibia. METHODS AND ANALYSIS This is an open-label cluster randomised controlled trial with 2×2 factorial design. The interventions include: rfMDA (presumptive treatment with artemether-lumefantrine (AL)) versus RACD (rapid diagnostic testing and treatment using AL) and RAVC (IRS with Acellic 300CS) versus no RAVC. Factorial design also enables comparison of the combined rfMDA+RAVC intervention to RACD. Participants living in 56 enumeration areas will be randomised to one of four arms: rfMDA, rfMDA+RAVC, RACD or RACD+RAVC. These interventions, triggered by index cases detected at health facilities, will be targeted to individuals residing within 500 m of an index. The primary outcome is cumulative incidence of locally acquired malaria detected at health facilities over 1 year. Secondary outcomes include seroprevalence, infection prevalence, intervention coverage, safety, acceptability, adherence, cost and cost-effectiveness. ETHICS AND DISSEMINATION Findings will be reported on clinicaltrials.gov, in peer-reviewed publications and through stakeholder meetings with MoHSS and community leaders in Namibia. TRIAL REGISTRATION NUMBER NCT02610400; Pre-results.
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Affiliation(s)
- Oliver F Medzihradsky
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
- Department of Pediatrics, Benioff Children's Hospital, University of California San Francisco, San Francisco, California, USA
| | - Immo Kleinschmidt
- Department of Infectious Disease Epidemiology, The London School of Hygiene and Tropical Medicine, London, UK
- Faculty of Health Sciences, School of Pathology, University of Witwatersrand, Johannesburg, South Africa
| | - Davis Mumbengegwi
- Multidisciplinary Research Centre, University of Namibia, Windhoek, Namibia
| | - Kathryn W Roberts
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Patrick McCreesh
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mi-Suk Kang Dufour
- Division of Prevention Science, University of California San Francisco, San Francisco, California, USA
| | - Petrina Uusiku
- National Vector-borne Diseases Control Programme, Ministry of Health and Social Services, Windhoek, Namibia
| | - Stark Katokele
- National Vector-borne Diseases Control Programme, Ministry of Health and Social Services, Windhoek, Namibia
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Jennifer Smith
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Hugh Sturrock
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Lisa M Prach
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Henry Ntuku
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Munyaradzi Tambo
- Faculty of Health Sciences, School of Pathology, University of Witwatersrand, Johannesburg, South Africa
| | - Bradley Didier
- Clinton Health Access Initiative, Boston, Massachusetts, USA
| | - Bryan Greenhouse
- Division of Experimental Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, USA
| | | | - Ann Aerts
- Novartis Foundation, Basel, Switzerland
| | - Roly Gosling
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, USA
- Department of Pediatrics, Benioff Children's Hospital, University of California San Francisco, San Francisco, California, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Arwati H, Yotopranoto S, Rohmah EA, Syafruddin D. Submicroscopic malaria cases play role in local transmission in Trenggalek district, East Java Province, Indonesia. Malar J 2018; 17:2. [PMID: 29301534 PMCID: PMC5755365 DOI: 10.1186/s12936-017-2147-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 12/19/2017] [Indexed: 12/24/2022] Open
Abstract
Background Trenggalek district is a hypoendemic malaria area with mainly imported cases brought by migrant workers from islands outside Java. During malaria surveillance in 2015, no malaria cases were found microscopically, but some cases were positive by PCR. Therefore, a study was conducted to prove that local malaria transmission still occur. Methods The adult villagers were invited to the house of the head of this village to be screened for malaria using aseptic venipuncture of 1 mL blood upon informed consent. Thin and thick blood films as well as blood spots on filter paper were made for each subject. The blood films were stained with Giemsa and the blood spots were used to extract DNA for polymerase chain reaction (PCR) amplification to determine the malaria infection. In addition, the history of malaria infection and travel to malaria endemic areas were recorded. Entomologic survey to detect the existence of anopheline vector was also conducted. Results Of the total 64 subjects that participated in the survey, no malaria parasites were found through microscopic examination of the blood films. The PCR analysis found six positive cases (two Plasmodium falciparum, one Plasmodium vivax and two mixed infection of both species), and two of them had no history of malaria and have never travelled to malaria endemic area. Entomologic survey using human bait trap detected the existence of Anopheles indefinitus that was found to be positive for P. vivax by PCR. Conclusions The results indicated that although we did not find any microscopically slide positive cases, six PCR positive subjects were found. The fact that 2 of the 6 malaria positive subjects have never travelled to malaria endemic area together with the existence of the vector confirm the occurence of local transmission of malaria in the area.
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Affiliation(s)
- Heny Arwati
- Department of Parasitology, Faculty of Medicine, Universitas Airlangga, Campus A, Jalan Prof. Moestopo No. 47, Surabaya, 60131, Indonesia.
| | - Subagyo Yotopranoto
- Department of Parasitology, Faculty of Medicine, Universitas Airlangga, Campus A, Jalan Prof. Moestopo No. 47, Surabaya, 60131, Indonesia
| | - Etik Ainun Rohmah
- Entomology Study Group, Institute of Tropical Diseases, Universitas Airlangga, Campus C, Jalan Ir. Soekarno, Surabaya, 60115, Indonesia
| | - Din Syafruddin
- Eijkman Institute for Molecular Biology, JalanDiponegoro 69, Jakarta, 10430, Indonesia.,Department of Parasitology, Faculty of Medicine, Hasanuddin University, Makassar, JalanPerintisKemerdekaan Km 10, Makassar, 90245, Indonesia
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Carter TE, Mekonnen SK, Lopez K, Bonnell V, Damodaran L, Aseffa A, Janies DA. Glucose-6-Phosphate Dehydrogenase Deficiency Genetic Variants in Malaria Patients in Southwestern Ethiopia. Am J Trop Med Hyg 2018; 98:83-87. [PMID: 29141760 PMCID: PMC5928732 DOI: 10.4269/ajtmh.17-0557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/08/2017] [Indexed: 12/26/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked erythrocyte enzyme disorder with relevance to malaria treatment policy. Treatment with the antimalarial primaquine can result in hemolytic anemia in G6PD-deficient patients. With increased interest in primaquine use, it is important to identify G6PD variants in Ethiopia to inform malaria treatment policy. In the present study, mutations in the G6PD gene are identified in a sample of patients with malaria in Jimma town in southwest Ethiopia. Plasmodium species of infection were confirmed using polymerase chain reaction (PCR) and gel electrophoresis. PCR and Sanger sequencing were performed to observe a portion of the G6PD gene where the common G6PD mutations (A376G, G202A, and C563T) are found. Molecular analysis revealed that most of the samples were single Plasmodium vivax infections (83.7%). For G6PD genotyping, A376G was detected in 23.26% of individuals, whereas G202A and C563T were absent. Three other uncommon mutations were identified: rs782669677 (535G→A), rs370658483, (485 + 37 G→T), and a new mutation at chrX:154535443(C→T). Bioinformatic analysis of these mutations' potential functional impact suggests minimal effect on protein function. The discovery of both common and uncommon G6PD mutations contributes to the discussion on G6PD deficiency and appropriate primaquine treatment in Ethiopia.
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Affiliation(s)
- Tamar E. Carter
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina
| | | | - Karen Lopez
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina
| | - Victoria Bonnell
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina
| | - Lambodhar Damodaran
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Daniel A. Janies
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina
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Tangchaikeeree T, Polpanich D, Bentaher A, Baraket A, Errachid A, Agusti G, Elaissari A, Jangpatarapongsa K. Combination of PCR and dual nanoparticles for detection of Plasmodium falciparum. Colloids Surf B Biointerfaces 2017; 159:888-897. [DOI: 10.1016/j.colsurfb.2017.08.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 08/17/2017] [Accepted: 08/31/2017] [Indexed: 01/10/2023]
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Spatial clustering of patent and sub-patent malaria infections in northern Namibia: Implications for surveillance and response strategies for elimination. PLoS One 2017; 12:e0180845. [PMID: 28820883 PMCID: PMC5562317 DOI: 10.1371/journal.pone.0180845] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/22/2017] [Indexed: 11/25/2022] Open
Abstract
Background Reactive case detection (RACD) around passively detected malaria cases is a strategy to identify and treat hotspots of malaria transmission. This study investigated the unproven assumption on which this approach is based, that in low transmission settings, infections cluster over small scales. Methods A prospective case-control study was conducted between January 2013 and August 2014 in Ohangwena and Omusati regions in north central Namibia. Patients attending health facilities who tested positive by malaria rapid diagnostic test (RDT) (index cases) were traced back to their home. All occupants of index case households (n = 116 households) and surrounding households (n = 225) were screened for Plasmodium infection with a rapid diagnostic test (RDT) and loop mediated isothermal amplification (LAMP) and interviewed to identify risk factors. A comparison group of 286 randomly-selected control households was also screened, to compare infection levels of RACD and non-RACD households and their neighbours. Logistic regression was used to investigate spatial clustering of patent and sub-patent infections around index cases and to identify potential risk factors that would inform screening approaches and identify risk groups. Estimates of the impact of RACD on onward transmission to mosquitoes was made using previously published figures of infection rates. Results Prevalence of Plasmodium falciparum infection by LAMP was 3.4%, 1.4% and 0.4% in index-case households, neighbors of index case households and control households respectively; adjusted odds ratio 6.1 [95%CI 1.9–19.5] comparing case households versus control households. Using data from Engela, neighbors of cases had higher odds of infection [adjusted OR 5.0 95%CI 1.3–18.9] compared to control households. All infections identified by RDTs were afebrile and RDTs identified only a small proportion of infections in case (n = 7; 17%) and control (0%) neighborhoods. Based on published estimates of patent and sub-patent infectiousness, these results suggest that infections missed by RDTs during RACD would allow 50–71% of infections to mosquitoes to occur in this setting. Conclusion Malaria infections cluster around passively detected cases. The majority of infections are asymptomatic and of densities below the limit of detection of current RDTs. RACD using standard RDTs are unlikely to detect enough malaria infections to dramatically reduce transmission. In low transmission settings such as Namibia more sensitive field diagnostics or forms of focal presumptive treatment should be tested as strategies to reduce malaria transmission.
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Niang M, Thiam LG, Sane R, Diagne N, Talla C, Doucoure S, Faye J, Diop F, Badiane A, Diouf B, Camara D, Diene-Sarr F, Sokhna C, Richard V, Toure-Balde A. Substantial asymptomatic submicroscopic Plasmodium carriage during dry season in low transmission areas in Senegal: Implications for malaria control and elimination. PLoS One 2017; 12:e0182189. [PMID: 28771615 PMCID: PMC5542561 DOI: 10.1371/journal.pone.0182189] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/13/2017] [Indexed: 11/19/2022] Open
Abstract
Background In the progress towards malaria elimination, the accurate diagnosis of low-density asymptomatic infections is critical. Low-density asymptomatic submicroscopic malaria infections may act as silent reservoirs that maintain low-level residual malaria transmission in the community. Light microscopy, the gold standard in malaria diagnosis lacks the sensitivity to detect low-level parasitaemia. In this study, the presence and prevalence of submicroscopic Plasmodium carriage were investigated to estimate the parasites reservoir among asymptomatic individuals living in low transmission areas in Dielmo and Ndiop, Senegal during the dry season. Methods A total of 2,037 blood samples were collected during cross-sectional surveys prior the malaria transmission season in July 2013 (N = 612), June 2014 (N = 723) and June 2015 (N = 702) from asymptomatic individuals living in Dielmo and Ndiop, Senegal. Samples were used to determine the prevalence of submicroscopic Plasmodium carriage by real time PCR (qPCR) in comparison to microscopy considered as gold standard. Results The prevalence of submicroscopic Plasmodium carriage was 3.75% (23/612), 12.44% (90/723) and 6.41% (45/702) in 2013, 2014 and 2015, respectively. No Plasmodium carriage was detected by microscopy in 2013 while microscopy-based prevalence of Plasmodium carriage accounted for only 0.27% (2/723) and 0.14% (1/702) in 2014 and 2015, respectively. Plasmodium falciparum accounted for the majority of submicroscopic infections and represented 86.95% (20/23), 81.11% (73/90) and 95.55 (43/45) of infections in 2013, 2014 and 2015 respectively. Conclusion Low-density submicroscopic asymptomatic Plasmodium carriage is common in the study areas during the dry season indicating that traditional measures are insufficient to assess the scale of parasite reservoir when transmission reaches very low level. Control and elimination strategies may wish to consider using molecular methods to identify parasites carriers to guide Mass screening and Treatment strategies.
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Affiliation(s)
- Makhtar Niang
- Immunology Unit, Institut Pasteur Dakar, Dakar, Sénégal
- * E-mail:
| | | | - Rokhaya Sane
- Immunology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | - Nafissatou Diagne
- French National Research Institute for Sustainable Development, URMITE, URMITE UMR 198, Dakar, Sénégal
| | - Cheikh Talla
- Epidemiology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | - Souleymane Doucoure
- French National Research Institute for Sustainable Development, URMITE, URMITE UMR 198, Dakar, Sénégal
| | - Joseph Faye
- Epidemiology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | - Fode Diop
- Immunology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | | | - Babacar Diouf
- Immunology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | - Diogop Camara
- Immunology Unit, Institut Pasteur Dakar, Dakar, Sénégal
| | | | - Cheikh Sokhna
- French National Research Institute for Sustainable Development, URMITE, URMITE UMR 198, Dakar, Sénégal
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Tadesse FG, van den Hoogen L, Lanke K, Schildkraut J, Tetteh K, Aseffa A, Mamo H, Sauerwein R, Felger I, Drakeley C, Gadissa E, Bousema T. The shape of the iceberg: quantification of submicroscopic Plasmodium falciparum and Plasmodium vivax parasitaemia and gametocytaemia in five low endemic settings in Ethiopia. Malar J 2017; 16:99. [PMID: 28253867 PMCID: PMC5335517 DOI: 10.1186/s12936-017-1749-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/24/2017] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The widespread presence of low-density asymptomatic infections with concurrent gametocytes may be a stumbling block for malaria elimination. This study investigated the asymptomatic reservoir of Plasmodium falciparum and Plasmodium vivax infections in schoolchildren from five settings in northwest Ethiopia. METHODS Two cross-sectional surveys were conducted in June and November 2015, enrolling 551 students from five schools and 294 students from three schools, respectively. Finger prick whole blood and plasma samples were collected. The prevalence and density of P. falciparum and P. vivax parasitaemia and gametocytaemia were determined by 18S rRNA quantitative PCR (qPCR) and pfs25 and pvs25 reverse transcriptase qPCR. Antibodies against blood stage antigens apical membrane antigen-1 (AMA-1) and merozoite surface protein-1 (MSP-119) were measured for both species. RESULTS Whilst only 6 infections were detected by microscopy in 881 slides (0.7%), 107 of 845 blood samples (12.7%) were parasite positive by (DNA-based) qPCR. qPCR parasite prevalence between sites and surveys ranged from 3.8 to 19.0% for P. falciparum and 0.0 to 9.0% for P. vivax. The median density of P. falciparum infections (n = 85) was 24.4 parasites/µL (IQR 18.0-34.0) and the median density of P. vivax infections (n = 28) was 16.4 parasites/µL (IQR 8.8-55.1). Gametocyte densities by (mRNA-based) qRT-PCR were strongly associated with total parasite densities for both P. falciparum (correlation coefficient = 0.83, p = 0.010) and P. vivax (correlation coefficient = 0.58, p = 0.010). Antibody titers against P. falciparum AMA-1 and MSP-119 were higher in individuals who were P. falciparum parasite positive in both surveys (p < 0.001 for both comparisons). DISCUSSION This study adds to the available evidence on the wide-scale presence of submicroscopic parasitaemia by quantifying submicroscopic parasite densities and concurrent gametocyte densities. There was considerable heterogeneity in the occurrence of P. falciparum and P. vivax infections and serological markers of parasite exposure between the examined low endemic settings in Ethiopia.
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Affiliation(s)
- Fitsum G Tadesse
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Medical Biotechnology Unit, Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.,Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia
| | - Lotus van den Hoogen
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jodie Schildkraut
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kevin Tetteh
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Abraham Aseffa
- Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
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Tangchaikeeree T, Sawaisorn P, Somsri S, Polpanich D, Putaporntip C, Tangboriboonrat P, Udomsangpetch R, Jangpatarapongsa K. Enhanced Sensitivity for Detection of Plasmodium falciparum gametocytes by magnetic nanoparticles combined with enzyme substrate system. Talanta 2016; 164:645-650. [PMID: 28107985 DOI: 10.1016/j.talanta.2016.10.106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/15/2016] [Accepted: 10/15/2016] [Indexed: 10/20/2022]
Abstract
The highly sensitive and specific detection of Pfg377 gene of Plasmodium falciparum gametocyte using Magnetic Nanoparticles PCR Enzyme-Linked Gene Assay (MELGA) was successfully developed. The MELGA included amplification of the Pfg377 gene by polymerase chain reaction (PCR) using magnetic nanoparticles (MNPs)-conjugated forward primer and biotinylated reverse primer, followed by post-analytical process using horseradish peroxidase (HRP)-conjugated streptavidin (SA). The complexes of MELGA product were incubated with the peroxidase substrate and hydrogen peroxide to produce the signal for colorimetric measurement. Altogether, the MELGA technique provided a highly sensitive and specific detection at 1 P. falciparum gametocyte/µL, which was more efficient than that of microscopic examination and rapid diagnostic tests (RDTs). Additionally, the MELGA could detect target gene at femtogram level, which was greater sensitive than the conventional PCR, nested PCR and loop-mediated isothermal amplification (LAMP). The MELGA technique could become a novel and practical method that overcome limitation of traditional gametocyte detection.
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Affiliation(s)
- Tienrat Tangchaikeeree
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Piamsiri Sawaisorn
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Sangdao Somsri
- Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani 12120, Thailand
| | - Duangporn Polpanich
- National Nanotechnology Center, National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathum Thani 12120, Thailand
| | - Chaturong Putaporntip
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | | | - Rachanee Udomsangpetch
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Kulachart Jangpatarapongsa
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.
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Etoka-Beka MK, Ntoumi F, Kombo M, Deibert J, Poulain P, Vouvoungui C, Kobawila SC, Koukouikila-Koussounda F. Plasmodium falciparum infection in febrile Congolese children: prevalence of clinical malaria 10 years after introduction of artemisinin-combination therapies. Trop Med Int Health 2016; 21:1496-1503. [PMID: 27671736 DOI: 10.1111/tmi.12786] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES To investigate the proportion of malaria infection in febrile children consulting a paediatric hospital in Brazzaville, to determine the prevalence of submicroscopic malaria infection, to characterise Plasmodium falciparum infection and compare the prevalence of uncomplicated P. falciparum malaria according to haemoglobin profiles. METHODS Blood samples were collected from children aged <10 years with an axillary temperature ≥37.5 °C consulting the paediatric ward of Marien Ngouabi Hospital in Brazzaville. Parasite density was determined and all samples were screened for P. falciparum by nested polymerase chain reaction (PCR) using the P. falciparum msp-2 marker to detect submicroscopic infections and characterise P. falciparum infection. Sickle cell trait was screened by PCR. RESULTS A total of 229 children with fever were recruited, of whom 10% were diagnosed with uncomplicated malaria and 21% with submicroscopic infection. The mean parasite density in children with uncomplicated malaria was 42 824 parasites/μl of blood. The multiplicity of infection (MOI) was 1.59 in children with uncomplicated malaria and 1.69 in children with submicroscopic infection. The mean haemoglobin level was 10.1 ± 1.7 for children with uncomplicated malaria and 12.0 ± 8.6 for children with submicroscopic infection. About 13% of the children harboured the sickle cell trait (HbAS); the rest had normal haemoglobin (HbAA). No difference in prevalence of uncomplicated malaria and submicroscopic infection, parasite density, haemoglobin level, MOI and P. falciparum genetic diversity was observed according to haemoglobin type. CONCLUSION The low prevalence of uncomplicated malaria in febrile Congolese children indicates the necessity to investigate carefully other causes of fever.
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Affiliation(s)
- Mandingha Kosso Etoka-Beka
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo.,Faculté des Sciences et Techniques, Marien Ngouabi University, Brazzaville, Congo
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo.,Faculté des Sciences et Techniques, Marien Ngouabi University, Brazzaville, Congo.,Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Michael Kombo
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo
| | - Julia Deibert
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Pierre Poulain
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo.,Institut National de la Santé et de la Recherche Médicale U 1134, Paris, France.,UMR_S 1134, DSIMB, Sorbonne Paris Cité, Université Paris Diderot, Paris, France.,Institut National de la Transfusion Sanguine, DSIMB, Paris, France.,UMR_S 1134, Laboratory of Excellence GR-Ex, DSIMB, Paris, France
| | - Christevy Vouvoungui
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo
| | | | - Felix Koukouikila-Koussounda
- Fondation Congolaise pour la Recherche Médicale, Faculté des Sciences de la Santé, Marien Ngouabi University, Brazzaville, Congo.,Faculté des Sciences et Techniques, Marien Ngouabi University, Brazzaville, Congo
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Surjadjaja C, Surya A, Baird JK. Epidemiology of Plasmodium vivax in Indonesia. Am J Trop Med Hyg 2016; 95:121-132. [PMID: 27708185 PMCID: PMC5201218 DOI: 10.4269/ajtmh.16-0093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 03/07/2016] [Indexed: 11/07/2022] Open
Abstract
Endemic malaria occurs across much of the vast Indonesian archipelago. All five species of Plasmodium known to naturally infect humans occur here, along with 20 species of Anopheles mosquitoes confirmed as carriers of malaria. Two species of plasmodia cause the overwhelming majority and virtually equal shares of malaria infections in Indonesia: Plasmodium falciparum and Plasmodium vivax. The challenge posed by P. vivax is especially steep in Indonesia because chloroquine-resistant strains predominate, along with Chesson-like strains that relapse quickly and multiple times at short intervals in almost all patients. Indonesia's hugely diverse human population carries many variants of glucose-6-phosphate dehydrogenase (G6PD) deficiency, most of them exhibiting severely impaired enzyme activity. Therefore, the patients most likely to benefit from primaquine therapy by preventing aggressive relapse, may also be most likely to suffer harm without G6PD deficiency screening. Indonesia faces the challenge of controlling and eventually eliminating malaria across > 13,500 islands stretching > 5,000 km and an enormous diversity of ecological, ethnographic, and socioeconomic settings, and extensive human migrations. This article describes the occurrence of P. vivax in Indonesia and the obstacles faced in eliminating its transmission.
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Affiliation(s)
| | - Asik Surya
- Sub-Directorate for Malaria Control, Ministry of Health, Jakarta, Indonesia
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Zhou G, Yewhalaw D, Lo E, Zhong D, Wang X, Degefa T, Zemene E, Lee MC, Kebede E, Tushune K, Yan G. Analysis of asymptomatic and clinical malaria in urban and suburban settings of southwestern Ethiopia in the context of sustaining malaria control and approaching elimination. Malar J 2016; 15:250. [PMID: 27129785 PMCID: PMC4851815 DOI: 10.1186/s12936-016-1298-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/15/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Malaria intervention in Ethiopia has been strengthened significantly in the past decade. The Ethiopian government recently stratified the country based upon annual parasite incidence into malaria free, low, moderate and high transmission strata. Districts with low transmission were targeted for indigenous transmission elimination. Surveillance on malaria disease incidence is needed for planning control and elimination efforts. METHODS Clinical malaria was monitored prospectively in health facilities in Jimma town, Oromia Region, southwestern Ethiopia from July 2014 to June 2015. Seasonal cross-sectional parasite prevalence surveys in local communities were conducted in 2014 and 2015 in eight kebeles. Case report forms were administered to obtain sociodemographic and epidemiological information from patients. RESULTS A total of 1434 suspected malaria cases were examined from the health facilities and 428 confirmed malaria cases were found. Among them, 327 (76.4 %) cases were Plasmodium vivax, 97 (22.7 %) were Plasmodium falciparum, and 4 (0.9 %) were mixed infection of P. vivax and P. falciparum. The annual malaria incidence rate was 1.7 cases per 1000 people at risk. Parasite prevalence in the community was less than 3 %. Household ownership of insecticide-treated nets (ITNs) was 47.3 % (1173/2479) and ITN usage was 37.9 %. All ITNs were long-lasting insecticidal nets, and repellent use was not found in the study area. Being male and traveling were the significant risk factors for P. falciparum malaria. For P. vivax malaria, risk factors included occupation and history of malaria illness during the preceding 30 days. CONCLUSION Epidemiological evidence suggested low clinical malaria incidence and prevalence in Jimma town. More aggressive measures may be needed to further suppress vivax transmission. Strategies should be planned targeting sustained control and elimination.
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Affiliation(s)
- Guofa Zhou
- />Program in Public Health, University of California, Irvine, CA 92617 USA
| | - Delenasaw Yewhalaw
- />Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- />Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Eugenia Lo
- />Program in Public Health, University of California, Irvine, CA 92617 USA
| | - Daibin Zhong
- />Program in Public Health, University of California, Irvine, CA 92617 USA
| | - Xiaoming Wang
- />Program in Public Health, University of California, Irvine, CA 92617 USA
| | - Teshome Degefa
- />Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Endalew Zemene
- />Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Ming-chieh Lee
- />Program in Public Health, University of California, Irvine, CA 92617 USA
| | - Estifanos Kebede
- />Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Kora Tushune
- />Department of Health Management, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Guiyun Yan
- />Program in Public Health, University of California, Irvine, CA 92617 USA
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Ayalew S, Mamo H, Animut A, Erko B. Assessment of Current Malaria Status in Light of the Ongoing Control Interventions, Socio-Demographic and Environmental Variables in Jiga Area, Northwest Ethiopia. PLoS One 2016; 11:e0146214. [PMID: 26751687 PMCID: PMC4709195 DOI: 10.1371/journal.pone.0146214] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 12/15/2015] [Indexed: 11/25/2022] Open
Abstract
Following substantial decline in malaria burden in Ethiopia, the country is planning to eliminate malaria in certain low transmission settings by 2020. To evaluate the attainability of this goal in-depth examination of malaria parasite carriage at community level is necessary. This study was, therefore, aimed at assessing the current situation of malaria in relation to ongoing control interventions in Jiga area, Jabi Tehnan District in northwest Ethiopia. A cross-sectional household (HH) survey was conducted in November-December 2013. Out of 2,574 HHs (11,815 people) in the entire Jabi Tehnan District, 392 (accommodating 1911 people) were randomly selected from three purposely selected villages. One randomly selected member from each selected HH was tested for malaria using rapid diagnostic test (mRDT). All participants tested for malaria (n = 392) were afebrile (axillary temperature <37.5°C). Eleven individuals (2.8%, 95% confidence interval (CI):1.2–4.4%) were found to be mRDT positive. Most HHs (95.9%, 95% CI: 93.5–97.5%) had at least 1 long-lasting insecticidal net (LLIN). Insecticide residual spraying (IRS) coverage the last six months was 85.5% (95% CI: 82.0–88.9%). Malaria prevalence remains unexpectedly high despite high HH coverage of control interventions.
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Affiliation(s)
- Seble Ayalew
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Abebe Animut
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
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Abstract
With increasing malaria control and goals of malaria elimination, many endemic areas are transitioning from high-to-low-to-no malaria transmission. Reductions in transmission will impact on the development of naturally acquired immunity to malaria, which develops after repeated exposure to Plasmodium spp. However, it is currently unclear how declining transmission and malaria exposure will affect the development and maintenance of naturally acquired immunity. Here we review the key processes which underpin this knowledge; the amount of Plasmodium spp. exposure required to generate effective immune responses, the longevity of antibody responses and the ability to mount an effective response upon re-exposure through memory responses. Lastly we identify research priorities which will increase our understanding of how changing transmission will impact on malarial immunity.
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