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Estep AS, Sanscrainte ND, Okech BA. Aedes aegypti Knockdown Resistance Mutations and Dengue Virus Infection in Haiti. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2024; 40:102-108. [PMID: 38547924 DOI: 10.2987/23-7160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Haiti is home to approximately 11 million people and has a high incidence of vector-borne disease, including more than 70,000 cases of dengue per year. Vector control is difficult in Haiti and adulticide spray of malathion is the main method of control employed during the outbreak of disease although pyrethroids are used in both bed net campaigns and in widely available aerosol cans for personal use. However, limited pathogen or insecticide resistance surveillance data are available for making operational decisions. In this study, we assessed Aedes aegypti from serial surveillance collections from 3 locations for the presence of dengue virus serotypes 1-3 (DENV1-3) by polymerase chain reaction and assessed, by melt curve analysis, samples from 10 locations in 2 departments for the presence of two mutations (V1016I and F1534C), that in combination, are linked to strong pyrethroid insecticide resistance. Only one of the 32 tested pools was positive for the presence of dengue virus. The two knockdown resistance (kdr) mutations were present in all locations. The 1016I mutation frequency varied from 0.29 to 0.91 and was in all sites lower than the 0.58-1.00 frequency of the 1534C mutation. We also observed that the genotype homozygous for both mutations (IICC), which has been linked to strong pyrethroid resistance, varied from 13 to 86% in each population. Notably, 3 locations - Ti Cousin and Christianville in Ouest department and Camp Coq in Nord department had more than 30% of the tested population without the presence of kdr mutations. These results indicate that the kdr markers of pyrethroid resistance are present in Haiti, at high frequency in several locations and, based on previous studies linking kdr genotypes and phenotypic resistance, that operational interventions with pyrethroids are not likely to be as effective as expected.
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Traoré N, Singhal T, Millogo O, Sié A, Utzinger J, Vounatsou P. Relative effects of climate factors and malaria control interventions on changes of parasitaemia risk in Burkina Faso from 2014 to 2017/2018. BMC Infect Dis 2024; 24:166. [PMID: 38326750 PMCID: PMC10848559 DOI: 10.1186/s12879-024-08981-2] [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: 06/16/2023] [Accepted: 01/03/2024] [Indexed: 02/09/2024] Open
Abstract
BACKGROUND In Burkina Faso, the prevalence of malaria has decreased over the past two decades, following the scale-up of control interventions. The successful development of malaria parasites depends on several climatic factors. Intervention gains may be reversed by changes in climatic factors. In this study, we investigated the role of malaria control interventions and climatic factors in influencing changes in the risk of malaria parasitaemia. METHODS Bayesian logistic geostatistical models were fitted on Malaria Indicator Survey data from Burkina Faso obtained in 2014 and 2017/2018 to estimate the effects of malaria control interventions and climatic factors on the temporal changes of malaria parasite prevalence. Additionally, intervention effects were assessed at regional level, using a spatially varying coefficients model. RESULTS Temperature showed a statistically important negative association with the geographic distribution of parasitaemia prevalence in both surveys; however, the effects of insecticide-treated nets (ITNs) use was negative and statistically important only in 2017/2018. Overall, the estimated number of infected children under the age of 5 years decreased from 704,202 in 2014 to 290,189 in 2017/2018. The use of ITNs was related to the decline at national and regional level, but coverage with artemisinin-based combination therapy only at regional level. CONCLUSION Interventions contributed more than climatic factors to the observed change of parasitaemia risk in Burkina Faso during the period of 2014 to 2017/2018. Intervention effects varied in space. Longer time series analyses are warranted to determine the differential effect of a changing climate on malaria parasitaemia risk.
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Affiliation(s)
- Nafissatou Traoré
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, CH-4001, Basel, Switzerland
- Nouna Health Research Centre, National Institute of Public Health, BP 02, Nouna, Burkina Faso
| | - Taru Singhal
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, CH-4001, Basel, Switzerland
| | - Ourohiré Millogo
- Nouna Health Research Centre, National Institute of Public Health, BP 02, Nouna, Burkina Faso
- Institut de Recherche en Sciences de la Santé/Centre National de Recherche Scientifique et Technologique, 01 BP, 2779, Bobo-Dioulasso, Burkina Faso
| | - Ali Sié
- Nouna Health Research Centre, National Institute of Public Health, BP 02, Nouna, Burkina Faso
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, CH-4001, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123, Allschwil, Switzerland.
- University of Basel, Petersplatz 1, CH-4001, Basel, Switzerland.
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Gabaldón Figueira JC, Wagah MG, Adipo LB, Wanjiku C, Maia MF. Topical repellents for malaria prevention. Cochrane Database Syst Rev 2023; 8:CD015422. [PMID: 37602418 PMCID: PMC10440788 DOI: 10.1002/14651858.cd015422.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
BACKGROUND Insecticide-based interventions, such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), remain the backbone of malaria vector control. These interventions target mosquitoes that prefer to feed and rest indoors, but have limited capacity to prevent transmission that occurs outdoors or outside regular sleeping hours. In low-endemicity areas, malaria elimination will require that these control gaps are addressed, and complementary tools are found. The use of topical repellents may be particularly useful for populations who may not benefit from programmatic malaria control measures, such as refugees, the military, or forest goers. This Cochrane Review aims to measure the effectiveness of topical repellents to prevent malaria infection among high- and non-high-risk populations living in malaria-endemic regions. OBJECTIVES To assess the effect of topical repellents alone or in combination with other background interventions (long-lasting insecticide-treated nets, or indoor residual spraying, or both) for reducing the incidence of malaria in high- and non-high-risk populations living in endemic areas. SEARCH METHODS We searched the following databases up to 11 January 2023: the Cochrane Infectious Diseases Group Specialised Register; CENTRAL (in the Cochrane Library); MEDLINE; Embase; CAB Abstracts; and LILACS. We also searched trial registration platforms and conference proceedings; and contacted organizations and companies for ongoing and unpublished trials. SELECTION CRITERIA We included randomized controlled trials (RCTs) and cluster-randomized controlled trials (cRCTs) of topical repellents proven to repel mosquitoes. We also included non-randomized studies that complied with pre-specified inclusion criteria: controlled before-after studies (CBA), controlled interrupted time series (ITS), and controlled cross-over trials. DATA COLLECTION AND ANALYSIS Four review authors independently assessed trials for inclusion, and extracted the data. Two authors independently assessed the risk of bias (RoB) using the Cochrane RoB 2 tool. A fifth review author resolved any disagreements. We analysed data by conducting a meta-analysis, stratified by whether studies included populations considered to be at high-risk of developing malaria infection (for example, refugees, forest goers, or deployed military troops). We combined results from cRCTs with RCTs by adjusting for clustering and presented results using forest plots. We used the GRADE framework to assess the certainty of the evidence. We only included data on Plasmodium falciparum infections in the meta-analysis. MAIN RESULTS Thirteen articles relating to eight trials met the inclusion criteria and were qualitatively described. We included six trials in the meta-analysis (five cRCTs and one RCT). Effect on malaria incidence Topical repellents may slightly reduce P falciparum infection and clinical incidence when both outcomes are considered together (incidence rate ratio (IRR) 0.74, 95% confidence interval (CI) 0.56 to 0.98; 3 cRCTs and 1 RCT, 61,651 participants; low-certainty evidence); but not when these two outcomes were considered independently. Two cRCTs and one RCT (12,813 participants) evaluated the effect of topical repellents on infection incidence (IRR 0.76, 95% CI 0.56 to 1.02; low-certainty evidence). One cRCT (48,838 participants) evaluated their effect on clinical case incidence (IRR 0.66, 95% CI 0.32 to 1.36; low-certainty evidence). Three studies (2 cRCTs and 1 RCT) included participants belonging to groups considered at high-risk of being infected, while only one cRCT did not include participants at high risk. Adverse events Topical repellents are considered safe. The prevalence of adverse events among participants who used topical repellents was very low (0.6%, 283/47,515) and limited to mild skin reactions. Effect on malaria prevalence Topical repellents may slightly reduce P falciparum prevalence (odds ratio (OR) 0.81, 95% CI 0.67 to 0.97; 3 cRCTs and 1 RCT; 55,366 participants; low-certainty evidence). Two of these studies (1 cRCT and 1 RCT) were carried out in refugee camps, and included exclusively high-risk populations that were not receiving any other background vector control intervention. AUTHORS' CONCLUSIONS There is insufficient evidence to conclude that topical repellents can prevent malaria in settings where other vector control interventions are in place. We found the certainty of evidence for all outcomes to be low, primarily due to the risk of bias. A protective effect was suggested among high-risk populations, specially refugees, who might not have access to other standard vector control measures. More adequately powered clinical trials carried out in refugee camps could provide further information on the potential benefit of topical repellents in this setting. Individually randomized studies are also likely necessary to understand whether topical repellents have an effect on personal protection, and the degree to which diversion to non-protected participants affects overall transmission dynamics. Despite this, the potential additional benefits of topical repellents are most likely limited in contexts where other interventions are available.
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Affiliation(s)
| | - Martin G Wagah
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | - Lawrence Babu Adipo
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Caroline Wanjiku
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Marta F Maia
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Solanke BL, Soladoye DA, Birsirka IA, Abdurraheem A, Salau OR. Utilization of insecticide-treated nets and associated factors among childbearing women in Northern Nigeria. Malar J 2023; 22:184. [PMID: 37328856 DOI: 10.1186/s12936-023-04620-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/12/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Studies have explored the correlates of insecticide-treated nets in Nigeria. The few studies that focused on Northern Nigeria mostly examined individual correlates, but largely ignored the community correlates. Also, the persistence of armed insurgencies in the region calls for more research attention. This study examines the utilization and the associated individual and community factors of insecticide-treated nets in Northern Nigeria. METHODS The study adopted a cross-sectional design. Data were extracted from the 2021 Nigeria Malaria Indicator Survey (NMIS). A weighted sample size of 6873 women was analysed. The outcome variable was the utilization of insecticide-treated nets. The explanatory variables selected at the individual/household level were maternal age, maternal education, parity, religion, sex of head of household, household wealth, and household size. The variables selected at the community level were the type of place of residence, geo-political zone of residence, the proportion of children under five who slept under a bed net, the proportion of women aged 15-49 who heard malaria media messages, and the community literacy level. Two variables, namely, the number of mosquito bed nets in the household, and the number of rooms used for sleeping were included for statistical control. Three multilevel mixed-effect regression models were fitted. RESULTS The majority of childbearing women (71.8%) utilized insecticide-treated nets. Parity and household size were the significant individual/household characteristics associated with the utilization of insecticide-treated nets. The proportion of under-five children in the community who slept under mosquito bed nets, and the geopolitical zone of residence were significant community correlates of the use of insecticide-treated nets. In addition, the number of rooms for sleeping, and the number of mosquito bed nets in the households were significantly associated with the utilization of insecticide-treated nets. CONCLUSION Parity, household size, number of sleeping rooms, number of treated bed nets, geo-political zone of residence, and proportion of under-five children sleeping under bed nets are important associated factors of the utilization of insecticide-treated nets in Northern Nigeria. Existing malaria preventive initiatives should be strengthened to target these characteristics.
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Affiliation(s)
- Bola Lukman Solanke
- Department of Demography and Social Statistics, Obafemi Awolowo University, Ile-Ife, Nigeria.
| | - Daniel Alabi Soladoye
- Department of Demography and Social Statistics, Obafemi Awolowo University, Ile-Ife, Nigeria
| | | | | | - Omowumi Romoke Salau
- Department of Clinical Nursing Services, UHD Trust, Royal Bournemouth Dorset, Bournemouth, UK
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Florez D, Young AJ, Bernabé KJ, Hyman JM, Qu Z. Modeling Sustained Transmission of Wolbachia among Anopheles Mosquitoes: Implications for Malaria Control in Haiti. Trop Med Infect Dis 2023; 8:tropicalmed8030162. [PMID: 36977163 PMCID: PMC10056903 DOI: 10.3390/tropicalmed8030162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Wolbachia infection in Anopheles albimanus mosquitoes can render mosquitoes less capable of spreading malaria. We developed and analyzed a mechanistic compartmental ordinary differential equation model to evaluate the effectiveness of Wolbachia-based vector control strategies among wild Anopheles mosquitoes in Haiti. The model tracks the mosquito life stages, including egg, larva, and adult (male and female). It also accounts for critical biological effects, such as the maternal transmission of Wolbachia through infected females and cytoplasmic incompatibility, which effectively sterilizes uninfected females when they mate with infected males. We derive and interpret dimensionless numbers, including the basic reproductive number and next-generation numbers. The proposed system presents a backward bifurcation, which indicates a threshold infection that needs to be exceeded to establish a stable Wolbachia infection. The sensitivity analysis ranks the relative importance of the epidemiological parameters at baseline. We simulate different intervention scenarios, including prerelease mitigation using larviciding and thermal fogging before the release, multiple releases of infected populations, and different release times of the year. Our simulations show that the most efficient approach to establishing Wolbachia is to release all the infected mosquitoes immediately after the prerelease mitigation process. Moreover, the model predicts that it is more efficient to release during the dry season than the wet season.
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Affiliation(s)
- Daniela Florez
- Department of Mathematics, Tulane University, New Orleans, LA 70118, USA; (D.F.); (J.M.H.)
| | - Alyssa J. Young
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA; (A.J.Y.); (K.J.B.)
| | - Kerlly J. Bernabé
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA; (A.J.Y.); (K.J.B.)
| | - James M. Hyman
- Department of Mathematics, Tulane University, New Orleans, LA 70118, USA; (D.F.); (J.M.H.)
| | - Zhuolin Qu
- Department of Mathematics, University of Texas at San Antonio, San Antonio, TX 78249, USA
- Correspondence:
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Predicting Plasmodium falciparum infection status in blood using a multiplexed bead-based antigen detection assay and machine learning approaches. PLoS One 2022; 17:e0275096. [PMID: 36174056 PMCID: PMC9521833 DOI: 10.1371/journal.pone.0275096] [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: 10/28/2021] [Accepted: 09/10/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Plasmodium blood-stage infections can be identified by assaying for protein products expressed by the parasites. While the binary result of an antigen test is sufficient for a clinical result, greater nuance can be gathered for malaria infection status based on quantitative and sensitive detection of Plasmodium antigens and machine learning analytical approaches.
Methods
Three independent malaria studies performed in Angola and Haiti enrolled persons at health facilities and collected a blood sample. Presence and parasite density of P. falciparum infection was determined by microscopy for a study in Angola in 2015 (n = 193), by qRT-PCR for a 2016 study in Angola (n = 208), and by qPCR for a 2012–2013 Haiti study (n = 425). All samples also had bead-based detection and quantification of three Plasmodium antigens: pAldolase, pLDH, and HRP2. Decision trees and principal component analysis (PCA) were conducted in attempt to categorize P. falciparum parasitemia density status based on continuous antigen concentrations.
Results
Conditional inference trees were trained using the known P. falciparum infection status and corresponding antigen concentrations, and PCR infection status was predicted with accuracies ranging from 73–96%, while level of parasite density was predicted with accuracies ranging from 59–72%. Multiple decision nodes were created for both pAldolase and HRP2 antigens. For all datasets, dichotomous infectious status was more accurately predicted when compared to categorization of different levels of parasite densities. PCA was able to account for a high level of variance (>80%), and distinct clustering was found in both dichotomous and categorical infection status.
Conclusions
This pilot study offers a proof-of-principle of the utility of machine learning approaches to assess P. falciparum infection status based on continuous concentrations of multiple Plasmodium antigens.
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Mukabane KD, Kitungulu NL, Ogutu PA, Cheruiyot JK, Tavasi NS, Mulama DH. Bed net use and malaria treatment-seeking behavior in artisanal gold mining and sugarcane growing areas of Western Kenya highlands. SCIENTIFIC AFRICAN 2022. [DOI: 10.1016/j.sciaf.2022.e01140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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There Is No Last Name For This Author P, Kaur H, Persoons L, Andrei G, Singh K. Quinoline-dihydropyrimidin-2(1H)-one hybrids: Synthesis, biological activity and mechanistic studies. ChemMedChem 2022; 17:e202200031. [PMID: 35174629 DOI: 10.1002/cmdc.202200031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/16/2022] [Indexed: 11/10/2022]
Abstract
A novel class of quinoline-dihydropyrimidin-2(1H)-one (DHPM) hybrids was synthesized and in vitro antiplasmodial activity was evaluated against chloroquine sensitive (D10) and chloroquine resistant (Dd2) strains of Plasmodium falciparum, the human malaria parasite. The antiplasmodial activity was compared to previously reported DHPM based molecular hybrids. Dual mode of antiplasmodial action of the most active member has been evaluated through heme binding study and in silico docking in the active site of dihydrofolate enzymes (wild-type as well as mutant). Favourable pharmacokinetic parameters were predicted in the ADMET evaluation. The new hybrids were also tested against a number of DNA and RNA viruses. No antiviral activity was found, except for one hybrid that showed mild inhibitory activity against two strains of cytomegalovirus (AD-169 and Davis), The most active hybrid was found to be a selective inhibitor of the growth of P. falciparum as well as a modest inhibitor of varicella zoster virus in HEL cells. Cytotoxicity of all hybrids was assessed in HEL, HeLa, Vero, MDCK, and CRFK cell cultures.
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Affiliation(s)
| | | | - Leentje Persoons
- KU Leuven: Katholieke Universiteit Leuven, Microbiology, BELGIUM
| | - Graciela Andrei
- KU Leuven: Katholieke Universiteit Leuven, Microbiology, BELGIUM
| | - Kamaljit Singh
- Guru Nanak Dev University, Chemistry, GT Road, 143005, Amritsar, INDIA
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Spatial cluster analysis of Plasmodium vivax and P. malariae exposure using serological data among Haitian school children sampled between 2014 and 2016. PLoS Negl Trop Dis 2022; 16:e0010049. [PMID: 34986142 PMCID: PMC8765618 DOI: 10.1371/journal.pntd.0010049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 01/18/2022] [Accepted: 12/03/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Estimation of malaria prevalence in very low transmission settings is difficult by even the most advanced diagnostic tests. Antibodies against malaria antigens provide an indicator of active or past exposure to these parasites. The prominent malaria species within Haiti is Plasmodium falciparum, but P. vivax and P. malariae infections are also known to be endemic. METHODOLOGY/PRINCIPAL FINDINGS From 2014-2016, 28,681 Haitian children were enrolled in school-based serosurveys and were asked to provide a blood sample for detection of antibodies against multiple infectious diseases. IgG against the P. falciparum, P. vivax, and P. malariae merozoite surface protein 19kD subunit (MSP119) antigens was detected by a multiplex bead assay (MBA). A subset of samples was also tested for Plasmodium DNA by PCR assays, and for Plasmodium antigens by a multiplex antigen detection assay. Geospatial clustering of high seroprevalence areas for P. vivax and P. malariae antigens was assessed by both Ripley's K-function and Kulldorff's spatial scan statistic. Of 21,719 children enrolled in 680 schools in Haiti who provided samples to assay for IgG against PmMSP119, 278 (1.27%) were seropositive. Of 24,559 children enrolled in 788 schools providing samples for PvMSP119 serology, 113 (0.46%) were seropositive. Two significant clusters of seropositivity were identified throughout the country for P. malariae exposure, and two identified for P. vivax. No samples were found to be positive for Plasmodium DNA or antigens. CONCLUSIONS/SIGNIFICANCE From school-based surveys conducted from 2014 to 2016, very few Haitian children had evidence of exposure to P. vivax or P. malariae, with no children testing positive for active infection. Spatial scan statistics identified non-overlapping areas of the country with higher seroprevalence for these two malarias. Serological data provides useful information of exposure to very low endemic malaria species in a population that is unlikely to present to clinics with symptomatic infections.
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Evolution of the Pyrethroids Target-Site Resistance Mechanisms in Senegal: Early Stage of the Vgsc-1014F and Vgsc-1014S Allelic Frequencies Shift. Genes (Basel) 2021; 12:genes12121948. [PMID: 34946897 PMCID: PMC8701854 DOI: 10.3390/genes12121948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/17/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
The evolution and spread of insecticide resistance mechanisms amongst malaria vectors across the sub-Saharan Africa threaten the effectiveness and sustainability of current insecticide-based vector control interventions. However, a successful insecticide resistance management plan relies strongly on evidence of historical and contemporary mechanisms circulating. This study aims to retrospectively determine the evolution and spread of pyrethroid resistance mechanisms among natural Anopheles gambiae s.l. populations in Senegal. Samples were randomly drawn from an existing mosquito sample, collected in 2013, 2017, and 2018 from 10 sentinel sites monitored by the Senegalese National Malaria Control Programme (NMCP). Molecular species of An. gambiae s.l. and the resistance mutations at the Voltage-gated Sodium Channel 1014 (Vgsc-1014) locus were characterised using PCR-based assays. The genetic diversity of the Vgsc gene was further analyzed by sequencing. The overall species composition revealed the predominance of Anopheles arabiensis (73.08%) followed by An. gambiae s.s. (14.48%), Anopheles coluzzii (10.94%) and Anopheles gambiae-coluzii hybrids (1.48%). Both Vgsc-1014F and Vgsc-1014S mutations were found in all studied populations with a spatial variation of allele frequencies from 3% to 90%; and 7% to 41%, respectively. The two mutations have been detected since 2013 across all the selected health districts, with Vgsc-L1014S frequency increasing over the years while Vgsc-1014F decreasing. At species level, the Vgsc-1014F and Vgsc-1014S alleles were more frequent amongst An. gambiae s.s. (70%) and An. arabiensis (20%). The Vgsc gene was found to be highly diversified with eight different haplotypes shared between Vgsc-1014F and Vgsc-1014S. The observed co-occurrence of Vgsc-1014F and Vgsc-1014S mutations suggest that pyrethroid resistance is becoming a widespread phenomenon amongst malaria vector populations, and the NMCP needs to address this issue to sustain the gain made in controlling malaria.
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Effectiveness of long-lasting insecticidal nets in prevention of malaria among individuals visiting health centres in Ziway-Dugda District, Ethiopia: matched case-control study. Malar J 2021; 20:301. [PMID: 34217315 PMCID: PMC8254940 DOI: 10.1186/s12936-021-03833-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 06/27/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is a major health problem in Ethiopia. Sleeping under long-lasting insecticidal nets (LLINs) is its major control strategy. Despite high LLINs use (84%) in Ziway-Dugda District, malaria remained a public health problem, raising concern on its effectiveness. Understanding the effectiveness of malaria control interventions is vital. This study evaluated the effectiveness of LLINs and determinants of malaria in Ziway-Dugda District, Arsi Zone Ethiopia. METHODS A matched case-control study was conducted among 284 study participants (71 cases and 213 controls) in Ziway-Dugda District, Arsi Zone, Ethiopia from March to May, 2017. Three health centers were selected randomly, and enrolled individuals newly diagnosed for malaria proportionally. Cases and controls were individuals testing positive and negative for malaria using rapid diagnostic tests. Each case was matched to three controls using the age of (5 years), gender and village of residence. The information was collected using pre-tested structured questionnaires through face to face interviews and observation. Data were entered into Epi-Info version 3.5, and analysed using Stata version-12. Conditional logistic regression was performed, and odds of LLINs use were compared using matched Adjusted Odds Ratio (AOR), 95% confidence interval (CI) and p-value of < 0.05. RESULTS One hundred twenty-three (61.2%) of the controls and 22 (32.8%) of cases had regularly slept under LLINs in the past two weeks. Using multivariate analysis, sleeping under LLINs for the past two weeks (AOR = 0.23, 95%CI = 0.11-0.45); living in houses sprayed with indoor residual spray (IRS) (AOR = 0.23, 95%CI: 0.10-0.52); and staying late outdoors at night in the past two-weeks (AOR = 2.99, 95%CI = 1.44-6.19) were determinant factors. CONCLUSIONS Sleeping under LLINs is effective for malaria prevention in the district. IRS and staying late outdoors at night were determinants of malaria. It is recommended to increase attention on strengthening LLINs use and IRS in the area.
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Roux AT, Maharaj L, Oyegoke O, Akoniyon OP, Adeleke MA, Maharaj R, Okpeku M. Chloroquine and Sulfadoxine-Pyrimethamine Resistance in Sub-Saharan Africa-A Review. Front Genet 2021; 12:668574. [PMID: 34249090 PMCID: PMC8267899 DOI: 10.3389/fgene.2021.668574] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Malaria is a great concern for global health and accounts for a large amount of morbidity and mortality, particularly in Africa, with sub-Saharan Africa carrying the greatest burden of the disease. Malaria control tools such as insecticide-treated bed nets, indoor residual spraying, and antimalarial drugs have been relatively successful in reducing the burden of malaria; however, sub-Saharan African countries encounter great challenges, the greatest being antimalarial drug resistance. Chloroquine (CQ) was the first-line drug in the 20th century until it was replaced by sulfadoxine-pyrimethamine (SP) as a consequence of resistance. The extensive use of these antimalarials intensified the spread of resistance throughout sub-Saharan Africa, thus resulting in a loss of efficacy for the treatment of malaria. SP was replaced by artemisinin-based combination therapy (ACT) after the emergence of resistance toward SP; however, the use of ACTs is now threatened by the emergence of resistant parasites. The decreased selective pressure on CQ and SP allowed for the reintroduction of sensitivity toward those antimalarials in regions of sub-Saharan Africa where they were not the primary drug for treatment. Therefore, the emergence and spread of antimalarial drug resistance should be tracked to prevent further spread of the resistant parasites, and the re-emergence of sensitivity should be monitored to detect the possible reappearance of sensitivity in sub-Saharan Africa.
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Affiliation(s)
- Alexandra T. Roux
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Leah Maharaj
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Olukunle Oyegoke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Oluwasegun P. Akoniyon
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Matthew Adekunle Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Rajendra Maharaj
- Office of Malaria Research, South African Medical Research Council, Cape Town, South Africa
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
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Druetz T, Stresman G, Ashton RA, Joseph V, van den Hoogen L, Worges M, Hamre KES, Fayette C, Monestime F, Impoinvil D, Rogier E, Chang MA, Lemoine JF, Drakeley C, Eisele TP. The Immediate Effects of a Combined Mass Drug Administration and Indoor Residual Spraying Campaign to Accelerate Progress towards Malaria Elimination in Grande-Anse, Haiti. J Infect Dis 2021; 225:1611-1620. [PMID: 33993294 PMCID: PMC9071345 DOI: 10.1093/infdis/jiab259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/12/2021] [Indexed: 11/18/2022] Open
Abstract
Background Haiti is planning targeted interventions to accelerate progress toward malaria elimination. In the most affected department (Grande-Anse), a combined mass drug administration (MDA) and indoor residual spraying (IRS) campaign was launched in October 2018. This study assessed the intervention’s effectiveness in reducing Plasmodium falciparum prevalence. Methods An ecological quasi-experimental study was designed, using a pretest and posttest with a nonrandomized control group. Surveys were conducted in November 2017 in a panel of easy access groups (25 schools and 16 clinics) and were repeated 2–6 weeks after the campaign, in November 2018. Single-dose sulfadoxine-pyrimethamine and primaquine was used for MDA, and pirimiphos-methyl as insecticide for IRS. Results A total of 10 006 participants were recruited. Fifty-two percent of the population in the intervention area reported having received MDA. Prevalence diminished between 2017 and 2018 in both areas, but the reduction was significantly larger in the intervention area (ratio of adjusted risk ratios, 0.32 [95% confidence interval, .104–.998]). Conclusions Despite a moderate coverage, the campaign was effective in reducing P. falciparum prevalence immediately after 1 round. Targeted MDA plus IRS is useful in preelimination settings to rapidly decrease the parasite reservoir, an encouraging step to accelerate progress toward malaria elimination.
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Affiliation(s)
- Thomas Druetz
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA.,Department of Social and Preventive Medicine, School of Public Health, University of Montreal, Montreal QC, Canada.,Centre de Recherche en Santé Publique, Montreal QC, Canada
| | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Ruth A Ashton
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA
| | - Vena Joseph
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA
| | - Lotus van den Hoogen
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA
| | - Matt Worges
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA
| | - Karen E S Hamre
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta GA, USA.,CDC Foundation, Atlanta GA, USA
| | | | | | - Daniel Impoinvil
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta GA, USA
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta GA, USA
| | - Michelle A Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta GA, USA
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population (MSPP), Port-au-Prince, Haiti
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans LA, USA
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14
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Rogier E, Hamre KES, Joseph V, Plucinski MM, Presume J, Romilus I, Mondelus G, Elisme T, van den Hoogen L, Lemoine JF, Drakeley C, Ashton RA, Chang MA, Existe A, Boncy J, Stresman G, Druetz T, Eisele TP. Conventional and High-Sensitivity Malaria Rapid Diagnostic Test Performance in 2 Transmission Settings: Haiti 2017. J Infect Dis 2020; 221:786-795. [PMID: 31630194 DOI: 10.1093/infdis/jiz525] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/16/2019] [Indexed: 01/24/2023] Open
Abstract
Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDTs) identifying Plasmodium falciparum in clinical and community settings. In 2017, 1 household and 2 easy-access group surveys tested all participants (N = 32 506) by conventional and high-sensitivity RDTs. A subset of blood samples (n = 1154) was laboratory tested for HRP2 by bead-based immunoassay and for P. falciparum 18S rDNA by photo-induced electron transfer polymerase chain reaction. Both RDT types detected low concentrations of HRP2 with sensitivity estimates between 2.6 ng/mL and 14.6 ng/mL. Compared to the predicate HRP2 laboratory assay, RDT sensitivity ranged from 86.3% to 96.0% between tests and settings, and specificity from 90.0% to 99.6%. In the household survey, the high-sensitivity RDT provided a significantly higher number of positive tests, but this represented a very small proportion (<0.2%) of all participants. These data show that a high-sensitivity RDT may have limited utility in a malaria elimination setting like Haiti.
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Affiliation(s)
- Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Karen E S Hamre
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Vena Joseph
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
| | - Mateusz M Plucinski
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jacquelin Presume
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Ithamare Romilus
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Gina Mondelus
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Tamara Elisme
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Lotus van den Hoogen
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ruth A Ashton
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
| | - Michelle A Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Alexandre Existe
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Jacques Boncy
- Laboratorie National de Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Gillian Stresman
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas Druetz
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA.,Department of Social and Preventive Medicine, University of Montreal School of Public Health, Montreal, Quebec, Canada
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
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15
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Ashton RA, Joseph V, van den Hoogen LL, Tetteh KKA, Stresman G, Worges M, Druetz T, Chang MA, Rogier E, Lemoine JF, Drakeley C, Eisele TP. Risk Factors for Malaria Infection and Seropositivity in the Elimination Area of Grand'Anse, Haiti: A Case-Control Study among Febrile Individuals Seeking Treatment at Public Health Facilities. Am J Trop Med Hyg 2020; 103:767-777. [PMID: 32458784 PMCID: PMC7410432 DOI: 10.4269/ajtmh.20-0097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The island of Hispaniola aims to eliminate malaria by 2025; however, there are limited data to describe epidemiologic risk factors for malaria in this setting. A prospective case–control study was conducted at four health facilities in southwest Haiti, aiming to describe factors influencing the risk of current and past malaria infection. Cases were defined as individuals attending facilities with current or recent fever and positive malaria rapid diagnostic test (RDT), while controls were those with current or recent fever and RDT negative. Serological markers of recent and cumulative exposure to Plasmodium were assessed using the multiplex bead assay from dried blood spots and used for alternate case definitions. Kuldorff’s spatial scan statistic was used to identify local clusters of infection or exposure. Logistic regression models were used to assess potential risk factors for RDT positivity and recent exposure markers, including age-group, gender, and recruiting health facility as group-matching variables. A total of 192 cases (RDT positive) and 915 controls (RDT negative) were recruited. Consistent spatial clusters were identified for all three infection and exposure metrics, indicating temporal stability of malaria transmission at these sites. Risk factors included remoteness from health facilities and household construction, furthermore, insecticide-treated net ownership or use was associated with reduced odds of RDT positivity. These findings indicate the malaria risk in Grand’Anse is driven primarily by location. Travel, occupation, and other behavioral factors were not associated with malaria. These data can support the National Malaria Program to refine and target their intervention approaches, and to move toward elimination.
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Affiliation(s)
- Ruth A Ashton
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Vena Joseph
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Lotus L van den Hoogen
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Kevin K A Tetteh
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matt Worges
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Thomas Druetz
- Department of Social and Preventive Medicine, University of Montreal School of Public Health, Montreal, Canada.,Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Michelle A Chang
- Division of Parasitic Diseases and Malaria, Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Rogier
- Division of Parasitic Diseases and Malaria, Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministry of Public Health and Population, Port-au-Prince, Haiti
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana
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Nawa M, Halwindi H, Hangoma P. Modelling malaria reduction in a highly endemic country: Evidence from household survey, climate, and program data in Zambia. J Public Health Afr 2020; 11:1096. [PMID: 33209231 PMCID: PMC7649733 DOI: 10.4081/jphia.2020.1096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 10/17/2019] [Indexed: 12/03/2022] Open
Abstract
Substantial efforts have seen the reduction in malaria prevalence from 33% in 2006 to 19.4% in 2015 in Zambia. Many studies have used effect measures, such as odds ratios, of malaria interventions without combining this information with coverage levels of the interventions to assess how malaria prevalence would change if these interventions were scaled up. We contribute to filling this gap by combining intervention coverage information with marginal predictions to model the extent to which key interventions can bring down malaria in Zambia. We used logistic regression models and derived marginal effects using repeated cross-sectional survey data from the Malaria Indicator Survey (MIS) datasets for Zambia collected in 2010, 2012 and 2015. Average monthly temperature and rainfall data were obtained from climate explorer a satellite-generated database. We then conducted a counterfactual analysis using the estimated marginal effects and various hypothetical levels of intervention coverage to assess how different levels of coverage would affect malaria prevalence. Increasing IRS and ITNs from the 2015 levels of coverage of 28.9% and 58.9% respectively to at least 80% and rising standard housing to 20% from the 13.4% in 2015 may bring malaria prevalence down to below 15%. If the percentage of modern houses were increased further to 90%, malaria prevalence might decrease to 10%. Other than ITN and IRS, streamlining and increasing of the percentage of standard houses in malaria fight would augment and bring malaria down to the levels needed for focal malaria elimination. The effects of ITNs, IRS and Standard housing were pronounced in high than low epidemiological areas.
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Affiliation(s)
| | - Hikabasa Halwindi
- Department of Community and Family Medicine, University of Zambia, School of Public Health, Lusaka, Zambia
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17
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Malaria Outbreak Facilitated by Appearance of Vector-Breeding Sites after Heavy Rainfall and Inadequate Preventive Measures: Nwoya District, Northern Uganda, February-May 2018. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2020; 2020:5802401. [PMID: 32377206 PMCID: PMC7193302 DOI: 10.1155/2020/5802401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 03/16/2020] [Accepted: 03/21/2020] [Indexed: 12/23/2022]
Abstract
Background Malaria is a leading cause of morbidity and mortality in Uganda. In April 2018, malaria cases surged in Nwoya District, Northern Uganda, exceeding expected limits and thereby requiring epidemic response. We investigated this outbreak to estimate its magnitude, identify exposure factors for transmission, and recommend evidence-based control measures. Methods We defined a malaria case as onset of fever in a resident of Anaka subcounty, Koch Goma subcounty, and Nwoya Town Council, Nwoya District, with a positive rapid diagnostic test or microscopy for malaria from 1 February to 25 May 2018. We reviewed medical records in all health facilities of affected subcounties to find cases. In a case-control study, we compared exposure factors between case-persons and asymptomatic controls matched by age and village. We also conducted entomological assessments on vector density and behavior. Results We identified 3,879 case-persons (attack rate [AR] = 6.5%) and two deaths (case-fatality rate = 5.2/10,000). Females (AR = 8.1%) were more affected than males (AR = 4.7%) (p < 0.0001). Of all age groups, 5–18 years (AR = 8.4%) were most affected. Heavy rain started in early March 2018, and a propagated outbreak followed in the first week of April 2018. In the case-control study, 55% (59/107) of case-persons and 18% (19/107) of controls had stagnant water around households for several days following rainfall (ORM-H = 5.6, 95% CI = 3.0–11); 25% (27/107) of case-persons and 51% (55/107) of controls wore full extremity covering clothes during evening hours (ORM-H = 0.30, 95% CI = 0.20–0.60); 71% (76/107) of case-persons and 85% (91/107) of controls slept under a long-lasting insecticide-treated net (LLIN) 14 days before symptom onset (ORM-H = 0.43, 95% CI = 0.22–0.85); 37% (40/107) of case-persons and 52% (56/107) of controls had access to at least one LLIN per 2 household members (ORM-H = 0.54, 95% CI = 0.30–0.97). Entomological assessment indicated active breeding sites in the entire study area; Anopheles gambiae sensu lato species were the predominant vector. Conclusion Increased vector-breeding sites after heavy rainfall and inadequate malaria preventive measures were found to have contributed to this outbreak. We recommended increasing coverage for LLINs and larviciding breeding sites in the area.
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18
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Investigating the Effect of Prompt Treatment on Malaria Prevalence in Children Aged below Five Years in Zambia: A Nested Case-Control Study in a Cross-Sectional Survey. ADVANCES IN PUBLIC HEALTH 2020. [DOI: 10.1155/2020/4289420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background. In a highly malaria endemic country like Zambia, prompt treatment of cases is known to reduce morbidity and mortality; however, it is not known whether it has a role as an effective prevention strategy because of the presence of asymptomatic chronic carriers who do not seek treatment and maintain the reservoirs of infection in the population. This study investigated the role of treatment of malaria cases as a prevention strategy in low, moderate, and high endemic settings. Methods. A nested case-control design was employed using datasets from a large countrywide national Malaria Indicator Survey of 2015. Self-reported malaria cases (n = 209) who took treatment in the two weeks preceding the survey were matched with controls (n = 511) who did not report malaria and did not take treatment during the same period using nearest neighbour propensity score matching for age, sex, and district. The data were analysed using conditional logistic regression in STATA version 15.1. Results. The malaria cases were more likely to be from rural areas (p=0.001), poorest households (p=0.049), and who lived in improvised housing structures (p=0.004) compared with the controls. Data from low and moderate malaria endemic areas did not have sufficient cases for the analysis to proceed; however, data from high endemic areas showed borderline evidence (p=0.054) that prompt treatment reduces the risk of malaria by almost half in the short-term aOR 0.057 (95% CI 0.32–1.01). Conclusion. We found borderline evidence which suggests that prompt treatment of malaria cases even in high endemic areas has potential to reduce the risk of malaria by almost half in the short term.
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19
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Herman C, Huber CS, Jones S, Steinhardt L, Plucinski MM, Lemoine JF, Chang M, Barnwell JW, Udhayakumar V, Rogier E. Multiplex malaria antigen detection by bead-based assay and molecular confirmation by PCR shows no evidence of Pfhrp2 and Pfhrp3 deletion in Haiti. Malar J 2019; 18:380. [PMID: 31775743 PMCID: PMC6882344 DOI: 10.1186/s12936-019-3010-9] [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: 06/12/2019] [Accepted: 11/16/2019] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The Plasmodium falciparum parasite is the only human malaria that produces the histidine-rich protein 2 and 3 (HRP2/3) antigens. Currently, HRP2/3 are widely used in malaria rapid diagnostic tests (RDTs), but several global reports have recently emerged showing genetic deletion of one or both of these antigens in parasites. Deletion of these antigens could pose a major concern for P. falciparum diagnosis in Haiti which currently uses RDTs based solely on the detection of the HRP2/3 antigens. METHODS From September 2012 through February 2014, dried blood spots (DBS) were collected in Haiti from 9317 febrile patients presenting to 17 health facilities in 5 departments throughout the country as part of a bed net intervention study. All DBS from RDT positive persons and a random sampling of DBS from RDT negative persons were assayed for P. falciparum DNA by nested and PET-PCR (n = 2695 total). All PCR positive samples (n = 331) and a subset of PCR negative samples (n = 95) were assayed for three malaria antigens by a multiplex bead assay: pan-Plasmodium aldolase (pAldo), pan-Plasmodium lactate dehydrogenase (pLDH), and HRP2/3. Any samples positive for P. falciparum DNA, but negative for HRP2/3 antigens were tested by nested PCR for Pfhrp2 and Pfhrp3 gene deletions. RESULTS Of 2695 DBS tested for Plasmodium DNA, 345 (12.8%) were originally found to be positive for P. falciparum DNA; 331 of these had DBS available for antigen detection. Of these, 266 (80.4%) were positive for pAldo, 221 (66.8%) positive for pLDH, and 324 (97.9%) were positive for HRP2/3 antigens. Seven samples (2.1%) positive for P. falciparum DNA were not positive for any of the three antigens by the bead assay, and were investigated for potential Pfhrp2/3 gene deletion by PCR. These samples either successfully amplified Pfhrp2/3 genes or were at an estimated parasite density too low for sufficient DNA to perform successful genotyping. CONCLUSIONS Malaria positive samples in multiple Haitian sites were found to contain the HRP2/3 antigens, and no evidence was found of Pfhrp2/3 deletions. Malaria RDTs based on the detection of the HRP2/3 antigens remain a reliable P. falciparum diagnostic tool as Haiti works towards malaria elimination.
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Affiliation(s)
- Camelia Herman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.,CDC Foundation (CDCF), Atlanta, GA, USA
| | - Curtis S Huber
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Sophie Jones
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Atlanta Research and Education Foundation (AREF), Atlanta, GA, USA
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Mateusz M Plucinski
- U.S. President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jean F Lemoine
- Programme National de Contrôle de la Malaria/MSPP, Port-au-Prince, Haiti
| | - Michelle Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - John W Barnwell
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Venkatachalam Udhayakumar
- 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.
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20
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Antenatal visits are positively associated with uptake of tetanus toxoid and intermittent preventive treatment in pregnancy in Ivory Coast. BMC Public Health 2019; 19:1467. [PMID: 31694607 PMCID: PMC6836543 DOI: 10.1186/s12889-019-7847-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 10/25/2019] [Indexed: 01/02/2023] Open
Abstract
Background Malaria and tetanus infections among pregnant women represent two major public health problems in sub-Saharan Africa. Optimum use of Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (IPTp-SP) and immunization against tetanus among pregnant women during antenatal care (ANC) visits are recommended strategies to prevent these issues. Despite these recommendations, many women in Africa remain deprived of these cost-effective and life-saving interventions. In this study, we aimed to examine the prevalence of women using these two services, and the association between women’s uptake of IPTp-SP and tetanus toxoid (TT) with antenatal care use in Ivory Coast. Methods This study was based on the fifth round of Multiple Indicator Cluster Survey (MICS 5) conducted in Ivory Coast in 2016. Participants were 9583 women aged between 15 and 49 years. Outcomes were TT and Intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP). Data analysis was conducted using bivariate and multiple logistic regression. Results In this study, the prevalence of taking TT immunization and IPTp-SP drugs was 81.97 and 17.83% respectively. Of the participants who took these drugs at all, the prevalence of taking adequate doses of TT immunization was 78.75% and that of IPTp-SP was 35.46%. In the multivariable analysis model, higher age groups, 25–29 years (OR = 2.028, 95%CI = 1.120–3.669) were found to be positively associated with uptake of adequate doses of IPTp-SP drugs. Women who attended at least four ANC visits had higher odds of taking IPTp-SP drugs (OR = 1.656, 95%CI = 1.194–2.299) and TT immunization (OR = 2.347, 95%CI = 1.384–3.981), and also had higher odds of receiving adequate doses of IPTp-SP drugs (OR = 3.291, 95%CI = 2.157–5.020) and that of TT immunization (OR = 1.968, 95%CI = 1.398–2.771). The odds of taking IPTp-SP drugs were significantly higher among women with primary (OR = 2.504, 95%CI = 1.020–6.146) and secondary/higher education (OR = 3.298, 95%CI = 1.343–8.097) compared to those with no education. Also, women with higher parity had lower odds of taking TT immunization (OR = 0.218, 95%CI = 0.055–0.858) compared to those with lower parity. Findings from this study also revealed that the odds of taking adequate doses of IPTp-SP drugs were significantly lower among participants from Mandé du Nord ethnicity (OR = 0.378,95%CI = 0.145–0.983) compared to those from other ethnicities. Conclusion In this study, uptake of IPTp-SP drugs was much lower than TT immunization. High number of ANC visits were found to be significantly associated with taking IPTp-SP drugs and TT immunization and also with that of taking them in adequate doses. Vaccination promotion is necessary to protect pregnant women and reduce adverse health outcomes among the newborn in Ivory Coast.
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21
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Briët OJT, Impoinvil DE, Chitnis N, Pothin E, Lemoine JF, Frederic J, Smith TA. Models of effectiveness of interventions against malaria transmitted by Anopheles albimanus. Malar J 2019; 18:263. [PMID: 31370901 PMCID: PMC6670173 DOI: 10.1186/s12936-019-2899-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 05/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Most impact prediction of malaria vector control interventions has been based on African vectors. Anopheles albimanus, the main vector in Central America and the Caribbean, has higher intrinsic mortality, is more zoophilic and less likely to rest indoors. Therefore, relative impact among interventions may be different. Prioritizing interventions, in particular for eliminating Plasmodium falciparum from Haiti, should consider local vector characteristics. METHODS Field bionomics data of An. albimanus from Hispaniola and intervention effect data from southern Mexico were used to parameterize mathematical malaria models. Indoor residual spraying (IRS), insecticide-treated nets (ITNs), and house-screening were analysed by inferring their impact on the vectorial capacity in a difference-equation model. Impact of larval source management (LSM) was assumed linear with coverage. Case management, mass drug administration and vaccination were evaluated by estimating their effects on transmission in a susceptible-infected-susceptible model. Analogous analyses were done for Anopheles gambiae parameterized with data from Tanzania, Benin and Nigeria. RESULTS While LSM was equally effective against both vectors, impact of ITNs on transmission by An. albimanus was much lower than for An. gambiae. Assuming that people are outside until bedtime, this was similar for the impact of IRS with dichlorodiphenyltrichloroethane (DDT) or bendiocarb, and impact of IRS was less than that of ITNs. However, assuming people go inside when biting starts, IRS had more impact on An. albimanus than ITNs. While house-screening had less impact than ITNs or IRS on An. gambiae, it had more impact on An. albimanus than ITNs or IRS. The impacts of chemoprevention and chemotherapy were comparable in magnitude to those of strategies against An. albimanus. Chemo-prevention impact increased steeply as coverage approached 100%, whilst clinical-case management impact saturated because of remaining asymptomatic infections. CONCLUSIONS House-screening and repellent IRS are potentially highly effective against An. albimanus if people are indoors during the evening. This is consistent with historical impacts of IRS with DDT, which can be largely attributed to excito-repellency. It also supports the idea that housing improvements have played a critical role in malaria control in North America. For elimination planning, impact estimates need to be combined with feasibility and cost-analysis.
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Affiliation(s)
- Olivier J T Briët
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland.,University of Basel, Petersplatz 1, Basel, Switzerland
| | - Daniel E Impoinvil
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria/Entomology Branch, 1600 Clifton Road, Mail Stop-G49, Atlanta, GA, 30329, USA
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland.,University of Basel, Petersplatz 1, Basel, Switzerland
| | - Emilie Pothin
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland.,University of Basel, Petersplatz 1, Basel, Switzerland
| | | | - Joseph Frederic
- Programme National de Contrôle de la Malaria, Port-au-Prince, Haiti
| | - Thomas A Smith
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, 4051, Basel, Switzerland. .,University of Basel, Petersplatz 1, Basel, Switzerland.
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Peprah S, Dhudha H, Ally H, Masalu N, Kawira E, Chao CN, Genga IO, Mumia M, Were PA, Kinyera T, Otim I, Legason ID, Biggar RJ, Bhatia K, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. A population-based study of the prevalence and risk factors of low-grade Plasmodium falciparum malaria infection in children aged 0-15 years old in northern Tanzania. Trop Med Int Health 2019; 24:571-585. [PMID: 30843638 PMCID: PMC6499672 DOI: 10.1111/tmi.13225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Northern Tanzania experiences significant malaria-related morbidity and mortality, but accurate data are scarce. We update the data on patterns of low-grade Plasmodium falciparum malaria infection among children in northern Tanzania. METHODS Plasmodium falciparum malaria prevalence (pfPR) was assessed in a representative sample of 819 children enrolled in 94 villages in northern Tanzania between October 2015 and August 2016, using a complex survey design. Individual- and household-level risk factors for pfPR were elicited using structured questionnaires. pfPR was assessed using rapid diagnostic tests (RDTs) and thick film microscopy (TFM). Associations with pfPR, based on RDT, were assessed using adjusted odds ratios (aOR) and confidence intervals (CI) from weighted survey logistic regression models. RESULTS Plasmodium falciparum malaria prevalence (pfPR) was 39.5% (95% CI: 31.5, 47.5) by RDT and 33.4% (26.0, 40.6) by TFM. pfPR by RDT was inversely associated with higher-education parents, especially mothers (5-7 years of education: aOR 0.55; 95% CI: 0.31, 0.96, senior secondary education: aOR 0.10; 95% CI: 0.02, 0.55), living in a house near the main road (aOR 0.34; 95% CI: 0.15, 0.76), in a larger household (two rooms: aOR 0.40; 95% CI: 0.21, 0.79, more than two rooms OR 0.35; 95% CI: 0.20, 0.62). Keeping a dog near or inside the house was positively associated with pfPR (aOR 2.01; 95% CI: 1.26, 3.21). pfPR was not associated with bed-net use or indoor residual spraying. CONCLUSIONS Nearly 40% of children in northern Tanzania had low-grade malaria antigenaemia. Higher parental education and household metrics but not mosquito bed-net use were inversely associated with pfPR.
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Affiliation(s)
- Sally Peprah
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - Herry Dhudha
- EpideMiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) Study, Bugando Medical Center, Mwanza, Tanzania
| | - Hillary Ally
- EpideMiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) Study, Bugando Medical Center, Mwanza, Tanzania
| | - Nestory Masalu
- EpideMiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) Study, Bugando Medical Center, Mwanza, Tanzania
| | - Esther Kawira
- EMBLEM Study, Shirati Health and Educational Foundation, Shirati, Tanzania
| | - Colin N Chao
- EpideMiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) Study, Bugando Medical Center, Mwanza, Tanzania
| | - Isaiah O. Genga
- EMBLEM Study, Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Mediatrix Mumia
- EMBLEM Study, Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Pamela A. Were
- EMBLEM Study, Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Tobias Kinyera
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | | | - Robert J. Biggar
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - James J. Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - Ruth M. Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - Sam M. Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
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"Wherever doctors cannot reach, the sunshine can": overcoming potential barriers to malaria elimination interventions in Haiti. Malar J 2018; 17:393. [PMID: 30373575 PMCID: PMC6206681 DOI: 10.1186/s12936-018-2553-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Haiti and the Dominican Republic, the only two Caribbean countries with endemic malaria transmission, are committed to eliminating malaria. With a Plasmodium falciparum prevalence under 1% and a highly focal transmission, the efforts towards elimination in Haiti will include several community-based interventions that must be tailored to the local sociocultural context to increase their uptake. However, little is known about local community perceptions regarding malaria and the planned elimination interventions. The aim of this study is to develop a robust understanding of how to tailor, implement and promote malaria elimination strategies in Haiti. METHODS A cross-sectional qualitative study was conducted December 2015-August 2016 in Grande-Anse and the North Department in Haiti. Data collection included key informant interviews (n = 51), in-depth interviews (n = 15) and focus group discussions (n = 14) with health workers, traditional healers, teachers, priests or pastors, informal community leaders, public officials, and community members. Following a grounded theory approach, transcripts were coded and analysed using content analysis. Coded text was sorted by the types of interventions under consideration by the malaria elimination programme. RESULTS The level of knowledge about malaria was low. Many participants noted community beliefs about malaria being caused by magical phenomena in addition to vector-borne transmission. Participants described malaria as a problem rooted in the environment, with vector control the most noted method of prevention. Though participants noted malaria a severe disease, it ranked lower than other health problems perceived as more acute. Access barriers to healthcare were described including a lack of bed nets. Some distrust about pills, tests, and foreigners in general was expressed, and in few cases linked to previous experience with malaria campaigns under dictatorial regimes. CONCLUSIONS There are several potential barriers and opportunities to implement community-based malaria elimination interventions in rural Haiti. Elimination efforts should include the collaboration of voodoo priests and other traditional healers, be coupled with solutions to wider community concerns or other health interventions, and learn from previous or similar programmes, such as the campaign to eliminate lymphatic filariasis. It is essential to engage with communities and gain their trust to successfully implement targeted aggressive elimination activities.
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Weppelmann TA, Stephenson CJ, Musih E, Dame JB, Remy MY, Nicolas R, von Fricken ME. Elimination or more accurate estimation? Investigation of trends in malaria diagnoses in the Ouest Department of Haiti from 2008 to 2017. PLoS One 2018; 13:e0198070. [PMID: 29879170 PMCID: PMC5991735 DOI: 10.1371/journal.pone.0198070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/13/2018] [Indexed: 11/19/2022] Open
Abstract
Background According to the 2016 World Malaria Report, the malaria incidence in Haiti declined by > 40% between 2010 and 2015. Though elimination efforts have likely contributed, this time period also corresponded to a national change in diagnostic methods. Methods Monthly reports of aggregated patient data were acquired from five clinics in the Ouest Department of Haiti. Generalized linear models were used to compare the number of febrile patients tested, the number of positive tests, and the proportion of tests that were positive (TRP) before and after the national adoption of rapid diagnostic tests (RDTs). Results Prior to the earthquake when microcopy was used for diagnosis, a total of 1,727 patients with 557 (32.3%) positive; post-earthquake testing was reduced and the TPR was variable; during the post recovery period when RDTs were used exclusivly, a total of 5,132 patients were tested using RDTs, only 83 (1.62%) were positive. Compared to the pre-earthquake period, there was a 69% increase in the number of patients tested (IRR: 1.69; 95% CI IRR 1.59, 2.79), and a 97.0% decrease in the proportion of patients with a positive test result (IRR: 0.03; 95% CI IRR 0.02, 0.04) in the post-recovery period. Conclusions While the decline in malaria indicators between 2010 and 2015 has been cited as evidence of progress towards elimination, these reports derived estimates of the malaria burden in Haiti using two different diagnostic tests. Thus, comparison of these periods in the context of malaria elimination should be made with caution.
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Affiliation(s)
- Thomas A. Weppelmann
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States of America
| | - Caroline J. Stephenson
- Department of Global and Community Health, George Mason University, Fairfax, VA, United States of America
| | - Elisha Musih
- Department of Global and Community Health, George Mason University, Fairfax, VA, United States of America
| | - John B. Dame
- College of Veterinary Medicine, University of Florida, Gainesville, FL, United States of America
| | - Marie Y. Remy
- African Methodist Episcopal Church Service and Development Agency, Inc., Washington, DC, United States of America
| | - Robert Nicolas
- African Methodist Episcopal Church Service and Development Agency, Inc., Washington, DC, United States of America
| | - Michael E. von Fricken
- Department of Global and Community Health, George Mason University, Fairfax, VA, United States of America
- * E-mail:
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25
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Newell I, Wiskin C, Anthoney J, Meza G, de Wildt G. Preventing malaria in the Peruvian Amazon: a qualitative study in Iquitos, Peru. Malar J 2018; 17:31. [PMID: 29338719 PMCID: PMC5771103 DOI: 10.1186/s12936-018-2177-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/08/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In Peru, despite decades of concerted control efforts, malaria remains a significant public health burden. Peru has recently exhibited a dramatic rise in malaria incidence, impeding South America's progress towards malaria elimination. The Amazon basin, in particular the Loreto region of Peru, has been identified as a target for the implementation of intensified control strategies, aiming for elimination. No research has addressed why vector control strategies in Loreto have had limited impact in the past, despite vector control elsewhere being highly effective in reducing malaria transmission. This study employed qualitative methods to explore factors limiting the success of vector control strategies in the region. METHODS Twenty semi-structured interviews were conducted among adults attending a primary care centre in Iquitos, Peru, together with 3 interviews with key informants (health care professionals). The interviews focussed on how local knowledge, together with social and cultural attitudes, determined the use of vector control methods. RESULTS Five themes emerged. (a) Participants believed malaria to be embedded within their culture, and commonly blamed this for a lack of regard for prevention. (b) They perceived a shift in mosquito biting times to early evening, rendering night-time use of bed nets less effective. (c) Poor preventive practices were compounded by a consensus that malaria prevention was the government's responsibility, and that this reduced motivation for personal prevention. (d) Participants confused the purpose of space-spraying. (e) Participants' responses also exposed persisting misconceptions, mainly concerning the cause of malaria and best practices for its prevention. CONCLUSION To eliminate malaria from the Americas, region-specific strategies need to be developed that take into account the local social and cultural contexts. In Loreto, further research is needed to explore the potential shift in biting behaviour of Anopheles darlingi, and how this interacts with the population's social behaviours and current use of preventive measures. Attitudes concerning personal responsibility for malaria prevention and long-standing misconceptions as to the cause of malaria and best preventive practices also need to be addressed.
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Affiliation(s)
- Ian Newell
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Connie Wiskin
- Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - James Anthoney
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Graciela Meza
- Facultad de Medicina Humana, Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - Gilles de Wildt
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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Saluja S, Nwomeh B, Finlayson SRG, Holterman AL, Jawa RS, Jayaraman S, Juillard C, Krishnaswami S, Mukhopadhyay S, Rickard J, Weiser TG, Yang GP, Shrime MG. Guide to research in academic global surgery: A statement of the Society of University Surgeons Global Academic Surgery Committee. Surgery 2017; 163:463-466. [PMID: 29221877 DOI: 10.1016/j.surg.2017.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/09/2017] [Accepted: 10/04/2017] [Indexed: 11/15/2022]
Abstract
Global surgery is an emerging academic discipline that is developing in tandem with numerous policy and advocacy initiatives. In this regard, academic global surgery will be crucial for measuring the progress toward improving surgical care worldwide. However, as a nascent academic discipline, there must be rigorous standards for the quality of work that emerges from this field. In this white paper, which reflects the opinion of the Global Academic Surgery Committee of the Society for University Surgeons, we discuss the importance of research in global surgery, the methodologies that can be used in such research, and the challenges and benefits associated with carrying out this research. In each of these topics, we draw on existing examples from the literature to demonstrate our points. We conclude with a call for continued, high-quality research that will strengthen the discipline's academic standing and help us move toward improved access to and quality of surgical care worldwide.
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Affiliation(s)
- Saurabh Saluja
- Department of Surgery, Weill Cornell Medicine, New York, NY; Program in Global Surgery and Social Change, Harvard Medical School, Boston, MA.
| | - Benedict Nwomeh
- Pediatric Surgery, Nationwide Children's Hospital, Columbus, OH
| | | | - AiXuan L Holterman
- Department of Surgery, University of Illinois College of Medicine at Peoria, Peoria, IL
| | - Randeep S Jawa
- Department of Surgery, Stony Brook University School of Medicine, Stony Brook, NY
| | - Sudha Jayaraman
- VCU Program for Global Surgery, Department of Surgery, VCU School of Medicine, Richmond, VA
| | - Catherine Juillard
- Center for Global Surgical Studies, University of California, San Francisco, San Francisco, CA
| | | | - Swagoto Mukhopadhyay
- Program in Global Surgery and Social Change, Harvard Medical School, Boston, MA; Department of Surgery, University of Connecticut, West Hartford, CT
| | - Jennifer Rickard
- Department of Surgery and Critical Care, University of Minnesota, Minneapolis, MN
| | - Thomas G Weiser
- Department of Surgery, Stanford University Medical Center, Stanford, CA
| | - George P Yang
- Department of Surgery, Stanford University Medical Center, Stanford, CA
| | - Mark G Shrime
- Program in Global Surgery and Social Change, Harvard Medical School, Boston, MA
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Stephenson CJ, Rossheim ME, Frankenfeld CL, Boncy J, Okech BA, von Fricken ME. Cross-sectional analysis of the association between bedtime and malaria exposure in the Ouest and Sud-Est Departments of Haiti. Acta Trop 2017; 176:188-191. [PMID: 28818627 DOI: 10.1016/j.actatropica.2017.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/07/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION The governments of Haiti and the Dominican Republic have a binational agreement to work towards malaria elimination for the island of Hispaniola by the year 2020. Understanding malaria-related knowledge and behaviors can help inform elimination efforts. This study examined the association between social-behavioral factors, like bedtime and bed net ownership, with malaria seroconversion status among people in the Ouest and Sud-Est departments of Haiti. METHODS In 2013, cross-sectional survey data (n=377) and blood samples were collected from a convenience sample of individuals within community, clinic and school settings. Logistic regression models were constructed to examine associations between social-behavioral factors and malaria exposure, adjusting for potential confounders. RESULTS Compared to people going to bed between 6 and 8 pm, those going to bed between 8 and 10 pm were 2.67 (OR, 95% CI: 1.16-6.14) times as likely to have been exposed to malaria. Participants who reported going to bed after 10 pm were 5.96 times as likely to have had previous malaria exposure (OR, 95% CI: 2.26-15.7), compared to 6-8 pm. No significant associations were found between malaria exposure and either insecticide use nor bed net ownership. DISCUSSION These findings are consistent with suspected feeding behaviors of Anopheles albimanus, which prefers feeding at night and outdoors. Study findings may improve overall understanding of malaria transmission in Haiti and potentially guide future studies conducted in this region.
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Strengthening Evidence in Cleft and Craniofacial Surgery. J Craniofac Surg 2017; 29:302-303. [PMID: 29135729 DOI: 10.1097/scs.0000000000004101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Lemoine JF, Boncy J, Filler S, Kachur SP, Fitter D, Chang MA. Haiti's Commitment to Malaria Elimination: Progress in the Face of Challenges, 2010-2016. Am J Trop Med Hyg 2017; 97:43-48. [PMID: 29064360 PMCID: PMC5676634 DOI: 10.4269/ajtmh.16-0902] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Haiti is committed to malaria elimination by 2020. Following a 2010 earthquake and cholera epidemic, Haiti capitalized on investments in its health system to refocus on malaria elimination. Efforts, including expanding diagnostics, ensuring efficacy of standard treatments, building institutional capacity, and strengthening surveillance were undertaken to complement the broad health system strengthening activities. These efforts led to the adoption and scale-up of malaria rapid diagnostic tests as a diagnostic modality. In addition, drug-resistant monitoring has been established in the country, along with the development of molecular testing capacity for the Plasmodium falciparum parasite at the National Public Health Laboratory. The development and piloting of surveillance activities to include an enhanced community-based approach for testing and treatment of patients has increased the ability of the Ministry of Health to map foci of transmission and respond promptly to outbreaks. The reinforcement of evidence-based approaches coupled with strong collaboration among the Ministry of Health and partners has demonstrated that malaria elimination by 2020 is a realistic prospect.
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Affiliation(s)
- Jean Frantz Lemoine
- Programme National de la Contrôle de la Malaria, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Jacques Boncy
- Laboratoire National de la Santé Publique, Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | | | - S Patrick Kachur
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - David Fitter
- Division of Global Health Protection, Centers for Disease Control and Prevention, Port-au-Prince, Haiti
| | - Michelle A Chang
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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Msellemu D, Shemdoe A, Makungu C, Mlacha Y, Kannady K, Dongus S, Killeen GF, Dillip A. The underlying reasons for very high levels of bed net use, and higher malaria infection prevalence among bed net users than non-users in the Tanzanian city of Dar es Salaam: a qualitative study. Malar J 2017; 16:423. [PMID: 29061127 PMCID: PMC5653998 DOI: 10.1186/s12936-017-2067-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 10/16/2017] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Bed nets reduce malaria-related illness and deaths, by forming a protective barrier around people sleeping under them. When impregnated with long-lasting insecticide formulations they also repel or kill mosquitoes attempting to feed upon sleeping humans, and can even suppress entire populations of malaria vectors that feed predominantly upon humans. Nevertheless, an epidemiological study in 2012 demonstrated higher malaria prevalence among bed net users than non-users in urban Dar es Salaam, Tanzania. METHODS Focus group discussions were conducted with women from four selected wards of Dar es Salaam city, focusing on four major themes relating to bed net use behaviours: (1) reasons for bed net use, (2) reasons for not using bed nets, (3) stimuli or reminders for people to use a bed net (4) perceived reasons for catching malaria while using a bed net. An analytical method by framework grouping of relevant themes was used address key issues of relevance to the study objectives. Codes were reviewed and grouped into categories and themes. RESULTS All groups said the main reason for bed net use was protection against malaria. Houses with well-screened windows, with doors that shut properly, and that use insecticidal sprays against mosquitoes, were said not to use bed nets, while frequent attacks from malaria was the main stimulus for people to use bed nets. Various reasons were mentioned as potential reasons that compromise bed net efficacy, the most common of which were: (1) bed net sharing by two or more people, especially if one occupant tends to come to bed late at night, and does not tuck in the net 71%; (2) one person shares the bed but does not use the net, moving it away from the side on which s/he sleeps 68%; (3) ineffective usage habits, called ulalavi, in which a sprawling sleeper either touches the net while sleeping up against it or leaves a limb hanging outside of it 68%. Less common reasons mentioned included: (1) Small bed nets which become un-tucked at night (31%); (2) Bed nets with holes large enough to allow mosquitoes to pass (28%); and (3) Going to bed late after already being bitten outdoors (24%). CONCLUSIONS Behaviours associated with bed net use like; bed sharing, bed net non compliant-bedfellow, sleeping pattern like ulalavi and some physical bed net attributes compromise its effectiveness and supposedly increase of malaria infection to bed net users. While some well-screened houses looked to instigate low malaria prevalence to non-bed net users.
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Affiliation(s)
- Daniel Msellemu
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- Faculty of Natural Science, University of Basel, Petersplatz 1, Postfach 4003, Basel, Switzerland
| | - Aloysia Shemdoe
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
| | - Christina Makungu
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
| | - Yeromini Mlacha
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
| | - Khadija Kannady
- Dar es Salaam City Council Ministry of Regional Administrations and Local Government, Dar es Salaam, United Republic of Tanzania
| | - Stefan Dongus
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
- Faculty of Natural Science, University of Basel, Petersplatz 1, Postfach 4003, Basel, Switzerland
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Gerry F. Killeen
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Angel Dillip
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, Kiko Avenue, Mikocheni, PO Box 78373, Dar es Salaam, United Republic of Tanzania
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Polisye Kont Moustik: A Culturally Competent Approach to Larval Source Reduction in the Context of Lymphatic Filariasis and Malaria Elimination in Haiti. Trop Med Infect Dis 2017; 2:tropicalmed2030039. [PMID: 30270896 PMCID: PMC6082096 DOI: 10.3390/tropicalmed2030039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 08/12/2017] [Accepted: 08/13/2017] [Indexed: 11/17/2022] Open
Abstract
Community engagement has become an increasingly important focus of global health programs. Arbovirus emergence in the Americas (Zika and chikungunya virues), and global goals for malaria and lymphatic filariasis elimination, mean that community-based mosquito control has taken on a new salience. But how should mosquito control initiatives be designed and implemented in ways that best engage local people? What are the challenges and trade-offs of different strategies, not only for effectiveness but also for scale-up? In this paper, we describe the social and political dynamics of a pilot study in a small town in northern Haiti. With the aim of developing a culturally-competent approach to larval source management (LSM), our pilot project combined larval surveillance with environmental management, social engagement, community education, and larvicide application. Orientated around a network of 'Mosquito Police' (Polisye Kont Moustik, in Haitian Creole), our approach integrated elements of formative research, social learning, and community participation. Here, we reflect on the challenges we encountered in the field, from larval mapping, staff management, education and behavior change, engagement with formal and informal leaders, and community-based environmental cleanup. We discuss how these programmatic efforts were influenced and shaped by a complex range of social, cultural, political, and economic realities, and conclude by discussing the implications of our community-based approach for the elimination of lymphatic filariasis and malaria, and other vector-borne diseases, in Haiti.
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