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Biruksew A, Demeke A, Birhanu Z, Golassa L, Getnet M, Yewhalaw D. Schoolchildren with asymptomatic malaria are potential hotspot for malaria reservoir in Ethiopia: implications for malaria control and elimination efforts. Malar J 2023; 22:311. [PMID: 37845680 PMCID: PMC10580533 DOI: 10.1186/s12936-023-04736-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/30/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Schoolchildren with asymptomatic malaria infections often go undiagnosed and untreated, serving as reservoirs for infection that hamper malaria control and elimination efforts. In this context, little is known about the magnitude of asymptomatic malaria infections in apparently healthy schoolchildren in Ethiopia. This study was aimed at determining the prevalence of asymptomatic malaria infection and its associated factors in apparently healthy schoolchildren in Ethiopia. METHODS From September 2021 to January 2022, a school-based cross-sectional study was conducted on 994 apparently healthy schoolchildren (aged 6-15 years) selected from 21 primary schools in the Gomma district, of Jimma zone, southwestern Oromia, Ethiopia. A multi-stage sampling technique was used to select schools and participants. After allocating the total sample proportionally to each school and then to each grade, participants were selected using the lottery method from a list of student records (rosters). Finger-pricked blood samples were collected for microscopy blood film preparation and malaria rapid diagnostic test (RDT) (SD Bioline Malaria Ag Pf/Pv). Moreover, dry blood spots (DBSs) were prepared onto filter papers for quantitative real time polymerase chain reaction (qPCR) analysis. RESULTS As determined by RDT and microscopy, the prevalence of asymptomatic malaria was 2.20% and 1.51%, respectively. Using qPCR, the overall prevalence was 5.03% (50/994). Of this, Plasmodium falciparum, Plasmodium vivax and mixed infections accounted for 90%, 6% and 4%, respectively. Submicroscopic asymptomatic malaria infection was also accounted for 70% (35/50) of the overall prevalence. Household head age, nighttime outdoor activities of household heads, family history of malaria, absence of insecticide-treated nets (ITN), and presence of stagnant water around the houses are all significantly associated with asymptomatic malaria infections among schoolchildren. CONCLUSIONS This study found that both RDT and microscopy underestimated the prevalence of asymptomatic malaria in schoolchildren. However, qPCR was able to detect even low levels of parasitaemia and revealed a higher prevalence of asymptomatic submicroscopic malaria infections. The findings imply that schoolchildren with asymptomatic malaria infection are potential hotspot for malaria reservoir that fuels ongoing transmission. Therefore, it is imperative to include schoolchildren and schools in malaria intervention package and equally important is the adoption of more advanced and sensitive diagnostic tools, which would be crucial for successful malaria control and elimination efforts. Targeted interventions for asymptomatic malaria-infected schoolchildren can provide invaluable support to the National Malaria Control Programme in controlling and eventually eliminating the disease.
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Affiliation(s)
- Abdissa Biruksew
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
| | | | - Zewdie Birhanu
- Department of Health, Behavior, and Society, Faculty of Public Health, Institute of Health Jimma University, Jimma, Ethiopia
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Masrie Getnet
- Department of Biostatistics and Epidemiology, Faculty of Public Health, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIRC), Jimma University, Jimma, Ethiopia
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Gichuki PM, Kibe L, Mwatele C, Mwangangi J, Mbogo CM. Towards an integrated vector management approach for sustainable control of schistosomiasis and malaria in Mwea, Kirinyaga County, Kenya: Baseline epidemiological and vector results. Heliyon 2023; 9:e20966. [PMID: 37876477 PMCID: PMC10590948 DOI: 10.1016/j.heliyon.2023.e20966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 10/12/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023] Open
Abstract
Background Vector control is an important approach in the control of most parasitic and vector-borne diseases including malaria, and schistosomiasis. Distribution of these two infections often overlaps and in such areas it's more economically viable to employ an integrated approach in the control of their vectors which largely shares the same breeding ecosystem. We carried out a baseline epidemiological and vector surveys for malaria and schistosomiasis in Mwea, Kirinyaga County, in preparation for the upscaling of integrated vector management (IVM) for the two diseases. Methods This was a repeated cross sectional survey, where mosquito and snails were sampled during dry and wet seasons in three different ecological zones, Kiamaciri, Thiba and Murinduko to identify possible breeding sites. Mosquito larvae were collected using standard dippers, adults using CDC miniature light traps while snail vectors were sampled using standard snail scoops in different breeding habitats. A total of 1200 pupils from 12 primary schools were tested for malaria using rapid diagnostic tests (Malaria Pf/PAN Ag combo). Stool samples were processed using the Kato Katz technique for intestinal schistosomiasis. Results The overall prevalence of intestinal schistosomiasis was 9.08 % (95 % CI: 07.00-11.00), with Kiamaciri zone recording the highest prevalence at 19 % (95%CI: 15.00-23.00) and Murinduko zone the least at 0.17 % (95%CI: 0.00-0.01). Majority of the infections were of light intensity 78.9 % (95%CI: 70.04-86.13). There was no positive malaria case detected in this study. Of the 3208 adult mosquitoes sampled during the dry season, 20.6 % (95 % CI: 19.25-22.08) were Anopheles gambiae s.l while 79.4 % (95 % CI: 77.92-80.75) were culicines. During the wet season, 3378 adult mosquitoes were collected, of which 14.7 % (95 % CI: 13.56-15.98) were Anopheles gambiae s.l and 85.3 % (95 % CI: 84.02-86.44) culicines. Overall, 4085 mosquito larvae were collected during the two seasons, of which, 57.3 % and 42.7 % were anopheles and culicine respectively. Majority of the larvae (85.1 % (95%CI: 84.01-86.10) were collected during the wet season, with only 14.9 % (95%CI: 14.10-16.00) being collected during the dry season. A total of 2292 fresh water vector snails were collected with a majority (69.6 % (95%CI: 68.00-71.10) being Biomphalaria pffeiferi responsible for transmission of intestinal schistosomiasis. Conclusion This study demonstrates that intestinal schistosomiasis is prevalent in Kiamaciri and Thiba zones, and points to the possibility of active transmission of schistosomiasis in Murinduko zone. Malaria vectors were predominantly observed in all sites despite there being no malaria positive case. Culex quinquefaciatus responsible for the spread of several arboviruses was also observed. The presence of these vectors may lead to future disease outbreaks in the area if concerted control initiatives are not undertaken. The disease vectors shared the same breeding sites and thus its economical and feasible to adopt an integrated vector management approach in control efforts for these disease in the study area.
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Affiliation(s)
- Paul M. Gichuki
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
- School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200 Meru, Kenya
| | - Lydia Kibe
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
| | - Cassian Mwatele
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
| | - Joseph Mwangangi
- KEMRI-Wellcome Trust Research Programme, Public Health Unit, PO Box 43640 - 00100, Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI), Centre for Geographical Medicine Research-Coast (CGMR-C). P.O Box 230- 80108 Kilifi, Kenya
| | - Charles M. Mbogo
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
- KEMRI-Wellcome Trust Research Programme, Public Health Unit, PO Box 43640 - 00100, Nairobi, Kenya
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Biruksew A, Demeke A, Birhanu Z, Kebede E, Golassa L, Mathebula EM, Yewhalaw D. Diagnostic performance of NxTek™ Eliminate Malaria-Pf test for the detection of Plasmodium falciparum in school children with asymptomatic malaria. Malar J 2023; 22:112. [PMID: 36991438 DOI: 10.1186/s12936-023-04529-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
Abstract
Background
One of the major roadblocks to the falciparum malaria elimination programme is the presence of a portion of the population, such as school children, with asymptomatic malaria infection. Targeting such reservoirs of infections is critical to interrupting transmission and enhancing elimination efforts. The NxTek™ Eliminate Malaria Pf test is a highly sensitive rapid diagnostic test (hsRDT) for the detection of HRP-2. However, knowledge gaps exist in Ethiopia on the diagnostic performance of hsRDT for the detection of Plasmodium falciparum in school children with asymptomatic malaria.
Methods
A school-based cross-sectional study was conducted from September 2021 to January 2022 on 994 healthy school children (aged 6–15 years). Finger-pricked whole blood samples were collected for microscopy, hsRDT, conventional RDT (cRDT or SD Bioline Malaria Ag Pf/P.v), and QuantStudio™ 3 Real—Time PCR system (qPCR). The hsRDT was compared to cRDT and microscopy. qPCR and microscopy were used as reference methods.
Results
The prevalence of Plasmodium falciparum was 1.51%, 2.2%. 2.2% and 4.52%, by microscopy, hsRDT, cRDT and qPCR, respectively. Using qPCR as reference, the sensitivity of hsRDT was higher (48.89%) than the microscopy (33.3%), and showed 100% specificity and a positive predictive value (PPV). Microscopy showed similar specificity and PPV as hsRDT. Using microscopy as a reference, the diagnostic perforrmances of both hsRDT and cRDT were similar. Both RDTs demonstrated identical diagnostic performances in both comparison methods.
Conclusions
hsRDT has the same diagnostic performance as cRDT but improved diagnostic characteristics than microscopy for detection of P. falciparum in school children with asymptomatic malaria. It can be a useful tool for the national malaria elimination plan of Ethiopia.
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Mutero CM, Okoyo C, Girma M, Mwangangi J, Kibe L, Ng'ang'a P, Kussa D, Diiro G, Affognon H, Mbogo CM. Evaluating the impact of larviciding with Bti and community education and mobilization as supplementary integrated vector management interventions for malaria control in Kenya and Ethiopia. Malar J 2020; 19:390. [PMID: 33143707 PMCID: PMC7607826 DOI: 10.1186/s12936-020-03464-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/26/2020] [Indexed: 12/04/2022] Open
Abstract
Background Malaria prevention in Africa is mainly through the use of long-lasting insecticide treated nets (LLINs). The objective of the study was to assess the effect of supplementing LLINs with either larviciding with Bacillus thuringiensis israelensis (Bti) or community education and mobilization (CEM), or with both interventions in the context of integrated vector management (IVM). Methods The study involved a factorial, cluster-randomized, controlled trial conducted in Malindi and Nyabondo sites in Kenya and Tolay site in Ethiopia, to assess the impact of the following four intervention options on mosquitoes and malaria prevalence: LLINs only (arm 1); LLINs and Bti (arm 2); LLINs and CEM (arm 3); and, LLINs combined with Bti and CEM (arm 4). Between January 2013 and December 2015, CDC light traps were used to sample adult mosquitoes during the second, third and fourth quarter of each year in 10 houses in each of 16 villages at each of the three study sites. Larvae were sampled once a fortnight from potential mosquito-breeding habitats using standard plastic dippers. Cross-sectional malaria parasite prevalence surveys were conducted involving a total of 11,846 primary school children during the 3-year period, including 4800 children in Tolay, 3000 in Malindi and 4046 in Nyabondo study sites. Results Baseline relative indoor anopheline density was 0.11, 0.05 and 0.02 mosquitoes per house per night in Malindi, Tolay and Nyabondo sites, respectively. Nyabondo had the highest recorded overall average malaria prevalence among school children at 32.4%, followed by Malindi with 5.7% and Tolay 1.7%. There was no significant reduction in adult anopheline density at each of the three sites, which could be attributed to adding of the supplementary interventions to the usage of LLINs. Malaria prevalence was significantly reduced by 50% in Tolay when using LLINs coupled with application of Bti, community education and mobilization. The two other sites did not reveal significant reduction of prevalence as a result of combining LLINs with any of the other supplementary interventions. Conclusion Combining LLINs with larviciding with Bti and CEM further reduced malaria infection in a low prevalence setting in Ethiopia, but not at sites with relatively higher prevalence in Kenya. More research is necessary at the selected sites in Kenya to periodically determine the suite of vector control interventions and broader disease management strategies, which when integrated would further reduce adult anopheline populations and malaria prevalence beyond what is achieved with LLINs.
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Affiliation(s)
- Clifford M Mutero
- International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, 00100, Nairobi, Kenya. .,Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.
| | - Collins Okoyo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Melaku Girma
- Zoological Sciences Department, Addis Ababa University, Addis Ababa, Ethiopia
| | - Joseph Mwangangi
- Centre for Geographic Medicine Research, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Lydia Kibe
- Centre for Geographic Medicine Research, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Peter Ng'ang'a
- International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, 00100, Nairobi, Kenya
| | - Dereje Kussa
- International Centre of Insect Physiology and Ecology (ICIPE), Addis Ababa, Ethiopia
| | - Gracious Diiro
- International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, 00100, Nairobi, Kenya
| | - Hippolyte Affognon
- West and Central Africa Council for Agricultural Research and Development, Dakar, Senegal
| | - Charles M Mbogo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.,Centre for Geographic Medicine Research, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
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5
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Development of a quantitative, portable, and automated fluorescent blue-ray device-based malaria diagnostic equipment with an on-disc SiO 2 nanofiber filter. Sci Rep 2020; 10:6585. [PMID: 32313065 PMCID: PMC7171072 DOI: 10.1038/s41598-020-63615-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 04/03/2020] [Indexed: 12/04/2022] Open
Abstract
There is an urgent need to develop an automated malaria diagnostic system that can easily and rapidly detect malaria parasites and determine the proportion of malaria-infected erythrocytes in the clinical blood samples. In this study, we developed a quantitative, mobile, and fully automated malaria diagnostic system equipped with an on-disc SiO2 nanofiber filter and blue-ray devices. The filter removes the leukocytes and platelets from the blood samples, which interfere with the accurate detection of malaria by the blue-ray devices. We confirmed that the filter, which can be operated automatically by centrifugal force due to the rotation of the disc, achieved a high removal rate of leukocytes (99.7%) and platelets (90.2%) in just 30 s. The automated system exhibited a higher sensitivity (100%) and specificity (92.8%) for detecting Plasmodium falciparum from the blood of 274 asymptomatic individuals in Kenya when compared to the common rapid diagnosis test (sensitivity = 98.1% and specificity = 54.8%). This indicated that this system can be a potential alternative to conventional methods used at local health facilities, which lack basic infrastructure.
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6
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Ngasala B, Matata F, Mwaiswelo R, Mmbando BP. Anemia among Schoolchildren with Malaria and Soil-Transmitted Helminth Coinfections after Repeated Rounds of Mass Drug Administration in Muheza District, Tanzania. Am J Trop Med Hyg 2020; 101:1148-1155. [PMID: 31516116 DOI: 10.4269/ajtmh.19-0362] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Coinfections with malaria and soil-transmitted helminths (STHs) has been common among school-aged children in Tanzania. However, after a countrywide scaling up of interventions for malaria and STHs, there are limited data on the prevalence of malaria-STH coinfections and its effect on anemia in schoolchildren in Tanzania. We assessed the distribution and risk factors for malaria, STHs, and malaria-STH coinfections, and its relation to anemia among 445 primary schoolchildren in Muheza district. A semi-structured questionnaire was used to collect demographic characteristics of the children. Malaria rapid diagnostic test (mRDT) was used to diagnose malaria infection. Soil-transmitted helminths were diagnosed using the Kato-Katz technique. Primary outcome was anemia, defined as hemoglobin concentration < 11 g/dL. Chi-square (χ2) or Fisher's exact tests, Kruskal-Wallis or t-test, and logistic models were used as appropriate. Overall, the prevalence of malaria, STHs, malaria-STH coinfection, and anemia were 18.4%, 6.1%, 1.6%, and 19.8%, respectively. Anemic children were more likely to have malaria (adjusted odds ratio [aOR] = 4.538, 95% CI: 2.189-9.409), whereas frequent use of bed nets was associated with reduced risk of malaria (aOR = 0.234, 95% CI: 0.130-0.42). On the other hand, not always using latrines and eating raw uncooked food increased the risk of STH infection. The prevalence of anemia was high and was associated with both malaria and malaria-STH infections, therefore calling for more integrated malaria-STH control approaches to target school-aged children.
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Affiliation(s)
- Billy Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Ferdinand Matata
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Richard Mwaiswelo
- Department of Microbiology, Immunology, and Parasitology, Hubert Kairuki Memorial University, Dar es Salaam, Tanzania.,Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Bruno P Mmbando
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
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Ling XX, Jin JJ, Zhu GD, Wang WM, Cao YY, Yang MM, Zhou HY, Cao J, Huang JY. Cost-effectiveness analysis of malaria rapid diagnostic tests: a systematic review. Infect Dis Poverty 2019; 8:104. [PMID: 31888731 PMCID: PMC6937952 DOI: 10.1186/s40249-019-0615-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 12/09/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Rapid diagnostic tests (RDT) can effectively manage malaria cases and reduce excess costs brought by misdiagnosis. However, few studies have evaluated the economic value of this technology. The purpose of this study is to systematically review the economic value of RDT in malaria diagnosis. MAIN TEXT A detailed search strategy was developed to identify published economic evaluations that provide evidence regarding the cost-effectiveness of malaria RDT. Electronic databases including MEDLINE, EMBASE, Biosis Previews, Web of Science and Cochrane Library were searched from Jan 2007 to July 2018. Two researchers screened studies independently based on pre-specified inclusion and exclusion criteria. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist was applied to evaluate the quality of the studies. Then cost and effectiveness data were extracted and summarized in a narrative way. Fifteen economic evaluations of RDT compared to other diagnostic methods were identified. The overall quality of studies varied greatly but most of them were scored to be of high or moderate quality. Ten of the fifteen studies reported that RDT was likely to be a cost-effective approach compared to its comparisons, but the results could be influenced by the alternatives, study perspectives, malaria prevalence, and the types of RDT. CONCLUSIONS Based on available evidence, RDT had the potential to be more cost-effective than either microscopy or presumptive diagnosis. Further research is also required to draw a more robust conclusion.
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Affiliation(s)
- Xiao-Xiao Ling
- School of Public Health, Fudan University, Key Laboratory of Health Technology Assessment, National Health Commission, Shanghai, 200032, China
| | - Jia-Jie Jin
- School of Public Health, Fudan University, Key Laboratory of Health Technology Assessment, National Health Commission, Shanghai, 200032, China
| | - Guo-Ding Zhu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, 211166, China
- Public Health Research Centre, Jiangnan University, Wuxi, 214122, China
| | - Wei-Ming Wang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Yuan-Yuan Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Meng-Meng Yang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Hua-Yun Zhou
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China.
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, 211166, China.
- Public Health Research Centre, Jiangnan University, Wuxi, 214122, China.
| | - Jia-Yan Huang
- School of Public Health, Fudan University, Key Laboratory of Health Technology Assessment, National Health Commission, Shanghai, 200032, China.
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Chacky F, Runge M, Rumisha SF, Machafuko P, Chaki P, Massaga JJ, Mohamed A, Pothin E, Molteni F, Snow RW, Lengeler C, Mandike R. Nationwide school malaria parasitaemia survey in public primary schools, the United Republic of Tanzania. Malar J 2018; 17:452. [PMID: 30518365 PMCID: PMC6280377 DOI: 10.1186/s12936-018-2601-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/29/2018] [Indexed: 11/16/2022] Open
Abstract
Background A nationwide, school, malaria survey was implemented to assess the risk factors of malaria prevalence and bed net use among primary school children in mainland Tanzania. This allowed the mapping of malaria prevalence at council level and assessment of malaria risk factors among school children. Methods A cross-sectional, school, malaria parasitaemia survey was conducted in 25 regions, 166 councils and 357 schools in three phases: (1) August to September 2014; (2) May 2015; and, (3) October 2015. Children were tested for malaria parasites using rapid diagnostic tests and were interviewed about household information, parents’ education, bed net indicators as well as recent history of fever. Multilevel mixed effects logistic regression models were fitted to estimate odds ratios of risk factors for malaria infection and for bed net use while adjusting for school effect. Results In total, 49,113 children were interviewed and tested for malaria infection. The overall prevalence of malaria was 21.6%, ranging from < 0.1 to 53% among regions and from 0 to 76.4% among councils. The malaria prevalence was below 5% in 62 of the 166 councils and above 50% in 18 councils and between 5 and 50% in the other councils. The variation of malaria prevalence between schools was greatest in regions with a high mean prevalence, while the variation was marked by a few outlying schools in regions with a low mean prevalence. Overall, 70% of the children reported using mosquito nets, with the highest percentage observed among educated parents (80.7%), low land areas (82.7%) and those living in urban areas (82.2%). Conclusions The observed prevalence among school children showed marked variation at regional and sub-regional levels across the country. Findings of this survey are useful for updating the malaria epidemiological profile and for stratification of malaria transmission by region, council and age groups, which is essential for guiding resource allocation, evaluation and prioritization of malaria interventions. Electronic supplementary material The online version of this article (10.1186/s12936-018-2601-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Frank Chacky
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania. .,National Malaria Control Programme, Dar es Salaam, Tanzania.
| | - Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Julius J Massaga
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ally Mohamed
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania.,National Malaria Control Programme, Dar es Salaam, Tanzania
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Fabrizio Molteni
- National Malaria Control Programme, Dar es Salaam, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Robert W Snow
- KEMRI-Welcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Renata Mandike
- Ministry of Health, Community Development, Gender, Elderly, and Children, Dodoma, Tanzania.,National Malaria Control Programme, Dar es Salaam, Tanzania
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Osorio L, Garcia JA, Parra LG, Garcia V, Torres L, Degroote S, Ridde V. A scoping review on the field validation and implementation of rapid diagnostic tests for vector-borne and other infectious diseases of poverty in urban areas. Infect Dis Poverty 2018; 7:87. [PMID: 30173662 PMCID: PMC6120097 DOI: 10.1186/s40249-018-0474-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/01/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings. There is a need to know what rapid diagnostic technologies are available, have been properly assessed, and are being implemented to improve control of these diseases in the urban context. This paper characterizes evidence on the field validation and implementation in urban areas of rapid diagnostics for vector-borne diseases and other diseases of poverty. MAIN BODY A scoping review was conducted. Peer-reviewed and grey literature were searched using terms describing the targeted infectious diseases, diagnostics evaluations, rapid tests, and urban setting. The review was limited to studies published between 2000 and 2016 in English, Spanish, French, and Portuguese. Inclusion and exclusion criteria were refined post hoc to identify relevant literature regardless of study design and geography. A total of 179 documents of the 7806 initially screened were included in the analysis. Malaria (n = 100) and tuberculosis (n = 47) accounted for the majority of studies that reported diagnostics performance, impact, and implementation outcomes. Fewer studies, assessing mainly performance, were identified for visceral leishmaniasis (n = 9), filariasis and leptospirosis (each n = 5), enteric fever and schistosomiasis (each n = 3), dengue and leprosy (each n = 2), and Chagas disease, human African trypanosomiasis, and cholera (each n = 1). Reported sensitivity of rapid tests was variable depending on several factors. Overall, specificities were high (> 80%), except for schistosomiasis and cholera. Impact and implementation outcomes, mainly acceptability and cost, followed by adoption, feasibility, and sustainability of rapid tests are being evaluated in the field. Challenges to implementing rapid tests range from cultural to technical and administrative issues. CONCLUSIONS Rapid diagnostic tests for vector-borne and other diseases of poverty are being used in the urban context with demonstrated impact on case detection. However, most evidence comes from malaria rapid diagnostics, with variable results. While rapid tests for tuberculosis and visceral leishmaniasis require further implementation studies, more evidence on performance of current tests or development of new alternatives is needed for dengue, Chagas disease, filariasis, leptospirosis, enteric fever, human African trypanosomiasis, schistosomiasis and cholera.
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Affiliation(s)
- Lyda Osorio
- Epidemiology and Population Health Research Group, School of Public Health, Universidad del Valle, Calle 4B No. 36-00 Edif 118 Escuela de Salud Pública, Universidad del Valle Campus San Fernando, Cali, Colombia
| | - Jonny Alejandro Garcia
- Epidemiology and Population Health Research Group, School of Public Health, Universidad del Valle, Calle 4B No. 36-00 Edif 118 Escuela de Salud Pública, Universidad del Valle Campus San Fernando, Cali, Colombia
- School of Medicine, Universidad del Valle, Cali, Colombia
| | - Luis Gabriel Parra
- Epidemiology and Population Health Research Group, School of Public Health, Universidad del Valle, Calle 4B No. 36-00 Edif 118 Escuela de Salud Pública, Universidad del Valle Campus San Fernando, Cali, Colombia
- School of Medicine, Universidad del Valle, Cali, Colombia
| | - Victor Garcia
- Epidemiology and Population Health Research Group, School of Public Health, Universidad del Valle, Calle 4B No. 36-00 Edif 118 Escuela de Salud Pública, Universidad del Valle Campus San Fernando, Cali, Colombia
| | - Laura Torres
- Epidemiology and Population Health Research Group, School of Public Health, Universidad del Valle, Calle 4B No. 36-00 Edif 118 Escuela de Salud Pública, Universidad del Valle Campus San Fernando, Cali, Colombia
| | - Stéphanie Degroote
- University of Montreal Public Health Research Institute (IRSPUM), Montreal, Canada
| | - Valéry Ridde
- University of Montreal Public Health Research Institute (IRSPUM), Montreal, Canada
- French Institute for Research on Sustainable Development (IRD), Paris Descartes University, Population and Development Center (CEPED), Université Paris Sorbonne Cité, National Institute of Health and Medical Research (INSERM), Health, Vulnerabilities and Gender Relations South (SAGESUD), Paris, France
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Sultana M, Sheikh N, Mahumud RA, Jahir T, Islam Z, Sarker AR. Prevalence and associated determinants of malaria parasites among Kenyan children. Trop Med Health 2017; 45:25. [PMID: 29085254 PMCID: PMC5651573 DOI: 10.1186/s41182-017-0066-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 08/17/2017] [Indexed: 11/15/2022] Open
Abstract
Background Approximately 80% of deaths attributed to malaria worldwide occurred mainly in Africa in 2015. Kenya is one of the major malaria endemic countries, making malaria the leading public health concern in this country. This study intended to document the prevalence of malaria and determine associated factors including socioeconomic status among children aged 6 months to 14 years in Kenya. Methods This study analyzed the secondary data extracted from the 2015 Kenya Malaria Indicator Survey (KMIS), a cross-sectional country representative survey. Associations of demographic, socioeconomic, community-based, and behavioral factors with the prevalence of malaria in children were analyzed using multivariable logistic regression analysis. Results Data from 7040 children aged 6 months to 14 years were analyzed. The prevalence of malaria showed an upward trend in terms of age, with the highest prevalence among children aged 11–14 years. Prevalence was also higher among rural children (10.16%) compared to urban children (2.93%), as well as poor children (11.05%) compared to rich children (3.23%). The likelihood of having malaria was higher among children aged 10–14 years (AOR = 4.47, 95% CI = 3.33, 6.02; P < 0.001) compared with children aged under 5 years. The presence of anemia (AOR = 3.52, 95% CI = 2.78, 4.45; P < 0.001), rural residence (AOR = 1.71, 95% CI = 1.31, 2.22; P < 0.001), lack of a hanging mosquito net (AOR = 2.38, 95% CI = 1.78, 3.19; P < 0.001), primary education level of the household head (AOR = 1.15, 95% CI = 1.08, 2.25; P < 0.05), and other factors, such as the household having electricity and access to media such as television or radio, were also associated with the likelihood of infection. Conclusion This study demonstrated the need to focus on awareness programs to prevent malaria and to use existing knowledge in practice to control the malaria burden in Kenya. Furthermore, this study suggests that improving the information available through the mass media and introducing behavior change communication and intervention program specifically for those of poor socioeconomic status will help to reduce malaria cases.
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Affiliation(s)
- Marufa Sultana
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh
| | - Nurnabi Sheikh
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh
| | - Rashidul Alam Mahumud
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh
| | - Tania Jahir
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh
| | - Ziaul Islam
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh
| | - Abdur Razzaque Sarker
- Health Economics & Financing Research Group, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), 68 Shahid Tajuddin Ahmed Sharani, Mohakhali, Dhaka, 1212 Bangladesh.,University of Strathclyde, Glasgow, UK
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11
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Comparison of diagnostics for the detection of asymptomatic Plasmodium falciparum infections to inform control and elimination strategies. Nature 2015; 528:S86-93. [PMID: 26633770 DOI: 10.1038/nature16039] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The global burden of malaria has been substantially reduced over the past two decades. Future efforts to reduce malaria further will require moving beyond the treatment of clinical infections to targeting malaria transmission more broadly in the community. As such, the accurate identification of asymptomatic human infections, which can sustain a large proportion of transmission, is becoming a vital component of control and elimination programmes. We determined the relationship across common diagnostics used to measure malaria prevalence - polymerase chain reaction (PCR), rapid diagnostic test and microscopy - for the detection of Plasmodium falciparum infections in endemic populations based on a pooled analysis of cross-sectional data. We included data from more than 170,000 individuals comparing the detection by rapid diagnostic test and microscopy, and 30,000 for detection by rapid diagnostic test and PCR. The analysis showed that, on average, rapid diagnostic tests detected 41% (95% confidence interval = 26-66%) of PCR-positive infections. Data for the comparison of rapid diagnostic test to PCR detection at high transmission intensity and in adults were sparse. Prevalence measured by rapid diagnostic test and microscopy was comparable, although rapid diagnostic test detected slightly more infections than microscopy. On average, microscopy captured 87% (95% confidence interval = 74-102%) of rapid diagnostic test-positive infections. The extent to which higher rapid diagnostic test detection reflects increased sensitivity, lack of specificity or both, is unclear. Once the contribution of asymptomatic individuals to the infectious reservoir is better defined, future analyses should ideally establish optimal detection limits of new diagnostics for use in control and elimination strategies.
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Comparing insecticide-treated bed net use to Plasmodium falciparum infection among schoolchildren living near Lake Victoria, Kenya. Malar J 2015; 14:515. [PMID: 26696416 PMCID: PMC4688986 DOI: 10.1186/s12936-015-1031-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 12/02/2015] [Indexed: 11/10/2022] Open
Abstract
Background Under trial conditions insecticide-treated nets have been shown to provide significant clinical and mortality protection under a range of malaria transmission intensity conditions. There are, however, few operational impact data, notably in very intense transmission conditions. This study, reports on malaria infection among Kenyan schoolchildren living in areas of intense malaria transmission and their reported use of insecticide-treated bed nets. Methods 5188 children in 54 schools were randomly sampled from seven counties surrounding Lake Victoria between May and June 2014. A questionnaire was administered to schoolchildren in classes 2–6 on the use of a long-lasting, insecticide-treated net (LLIN) the night before the survey and provided a single blood sample for a rapid diagnostic test for malaria infection. Analysis of the impact of insecticide-treated net use on malaria prevalence was undertaken using a multivariable, mixed effects, logistic regression at 95 % confidence interval (CI), taking into account hierarchical nature of the data and results adjusted for school clusters. Results The overall prevalence of malaria infection was 48.7 %, two-thirds (67.9 %) of the children reported using LLIN, 91.3 % of the children reported that their households own at least one LLIN and the household LLIN coverage was 2.5 persons per one LLIN. The prevalence of infection showed variation across the counties, with prevalence being highest in Busia (66.9 %) and Homabay (51.8 %) counties, and lowest in Migori County (29.6 %). Generally, malaria parasite prevalence differed between age groups and gender with the highest prevalence occurring in children below 7 years (50.6 %) and males (52.2 %). Adjusting for county and school, there was a significant reduction in odds of malaria infection among the schoolchildren who reported LLIN use the previous night by 14 % (aOR 0.86, 95 % CI 0.74–0.98, P < 0.027). Conclusion Malaria transmission continues to be high around Lake Victoria. Despite evidence of increasing pyrethroid resistance and the likely overall efficacy of LLIN distributed several years prior to the survey, LLIN continue to provide protection against infection among school-aged children. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1031-6) contains supplementary material, which is available to authorized users.
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Ashton RA, Kefyalew T, Rand A, Sime H, Assefa A, Mekasha A, Edosa W, Tesfaye G, Cano J, Teka H, Reithinger R, Pullan RL, Drakeley CJ, Brooker SJ. Geostatistical modeling of malaria endemicity using serological indicators of exposure collected through school surveys. Am J Trop Med Hyg 2015; 93:168-177. [PMID: 25962770 PMCID: PMC4497890 DOI: 10.4269/ajtmh.14-0620] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 02/25/2015] [Indexed: 11/23/2022] Open
Abstract
Ethiopia has a diverse ecology and geography resulting in spatial and temporal variation in malaria transmission. Evidence-based strategies are thus needed to monitor transmission intensity and target interventions. A purposive selection of dried blood spots collected during cross-sectional school-based surveys in Oromia Regional State, Ethiopia, were tested for presence of antibodies against Plasmodium falciparum and P. vivax antigens. Spatially explicit binomial models of seroprevalence were created for each species using a Bayesian framework, and used to predict seroprevalence at 5 km resolution across Oromia. School seroprevalence showed a wider prevalence range than microscopy for both P. falciparum (0–50% versus 0–12.7%) and P. vivax (0–53.7% versus 0–4.5%), respectively. The P. falciparum model incorporated environmental predictors and spatial random effects, while P. vivax seroprevalence first-order trends were not adequately explained by environmental variables, and a spatial smoothing model was developed. This is the first demonstration of serological indicators being used to detect large-scale heterogeneity in malaria transmission using samples from cross-sectional school-based surveys. The findings support the incorporation of serological indicators into periodic large-scale surveillance such as Malaria Indicator Surveys, and with particular utility for low transmission and elimination settings.
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Affiliation(s)
- Ruth A. Ashton
- *Address correspondence to Ruth A. Ashton, Malaria Consortium, Development House, 56-64 Leonard Street, London. E-mail:
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Talisuna AO, Noor AM, Okui AP, Snow RW. The past, present and future use of epidemiological intelligence to plan malaria vector control and parasite prevention in Uganda. Malar J 2015; 14:158. [PMID: 25888989 PMCID: PMC4399081 DOI: 10.1186/s12936-015-0677-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 04/04/2015] [Indexed: 11/30/2022] Open
Abstract
Background An important prelude to developing strategies to control infectious diseases is a detailed epidemiological evidence platform to target cost-effective interventions and define resource needs. Methods A review of published and un-published reports of malaria vector control and parasite prevention in Uganda was conducted for the period 1900–2013. The objective was to provide a perspective as to how epidemiological intelligence was used to design malaria control before and during the global malaria eradication programme (GMEP) and to contrast this with the evidence generated in support of the Roll Back Malaria (RBM) initiative from 1998 to date. Results During the GMEP era, comprehensive investigations were undertaken on the effectiveness of vector and parasite control such as indoor residual house-spraying (IRS) and mass drug administration (MDA) at different sites in Uganda. Nationwide malariometric surveys were undertaken between 1964 and 1967 to provide a profile of risk, epidemiology and seasonality leading to an evidence-based national cartography of risk to characterize the diversity of malaria transmission in Uganda. At the launch of the RBM initiative in the late 1990s, an equivalent level of evidence was lacking. There was no contemporary national evidence-base for the likely impact of insecticide-treated nets (ITN), no new malariometric data, no new national cartography of malaria risk or any evidence of tailored intervention delivery based on variations in the ecology of malaria risk in Uganda. Discussion Despite millions of dollars of overseas development assistance over the last ten years in ITN, and more recently the resurrection of the use of IRS, the epidemiological impact of vector control remains uncertain due to an absence of nationwide basic parasite and vector-based field studies. Conclusion Readily available epidemiological data should become the future business model to maximize malaria funding from 2015. Over the next five to ten years, accountability, impact analysis, financial business cases supported by a culture of data use should become the new paradigm by which malaria programmes, governments and their development partners operate.
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Affiliation(s)
- Ambrose O Talisuna
- INFORM Project, Department of Public Health Research, KEMRI-Welcome Trust Research Programme, Nairobi, Kenya. .,Centre for Tropical Medicine & Global Health, Nuffield Department of Clinical Medicine, University of Oxford, CCVTM, Oxford, UK. .,Uganda Malaria Surveillance Programme (UMSP), Kampala, Uganda.
| | - Abdisalan M Noor
- INFORM Project, Department of Public Health Research, KEMRI-Welcome Trust Research Programme, Nairobi, Kenya. .,Centre for Tropical Medicine & Global Health, Nuffield Department of Clinical Medicine, University of Oxford, CCVTM, Oxford, UK.
| | - Albert P Okui
- Ministry of Health, National Malaria Control Programme, Plot 6 Lourdel Road Nakasero, Kampala, Uganda.
| | - Robert W Snow
- INFORM Project, Department of Public Health Research, KEMRI-Welcome Trust Research Programme, Nairobi, Kenya. .,Centre for Tropical Medicine & Global Health, Nuffield Department of Clinical Medicine, University of Oxford, CCVTM, Oxford, UK.
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Hawkes M, Conroy AL, Opoka RO, Namasopo S, Liles WC, John CC, Kain KC. Use of a three-band HRP2/pLDH combination rapid diagnostic test increases diagnostic specificity for falciparum malaria in Ugandan children. Malar J 2014; 13:43. [PMID: 24484540 PMCID: PMC3922073 DOI: 10.1186/1475-2875-13-43] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid diagnostic tests (RDTs) for malaria provide a practical alternative to light microscopy for malaria diagnosis in resource-limited settings. Three-band RDTs incorporating two parasite antigens may have enhanced diagnostic specificity, relative to two-band RDTs with a single parasite antigen (typically histidine-rich protein 2 [HRP2]). METHODS Phase 1: 2,000 children, two months to five years of age, admitted to a referral hospital in Jinja, Uganda, with acute febrile illness were enrolled. A WHO highly rated three-band RDT was compared to light microscopy of thick peripheral blood films read by local expert microscopists.Phase 2: the three-band RDT was used as a screening tool for inclusion of patients in a clinical trial, and subjects with three positive RDT bands were tested by microscopy using blood samples drawn in parallel. Discordant results were adjudicated by PCR. RESULTS Phase 1: 1,648 children had both a RDT and peripheral blood smear performed. The specificity of a RDT with all three bands positive was 82% (95% CI: 79-85%) compared to 62% (95% CI: 59-66%) for HRP2 alone. The sensitivity was 88% (95% CI: 85-89%) and 94% (95% CI: 92-95%) for three-band positive RDT and HRP2 antigen, respectively. 119 patients (7.2%) had a positive HRP2 band, but negative parasite lactate dehydrogenase (pLHD) band and negative peripheral smear, and 72 (61%) of these had received pre-treatment with anti-malarials, suggesting a false positive HRP2 result (p = 0.002).Phase 2: the positive predictive value (PPV) of the three-band RDT was 94% (95% CI 89%-97%) using microscopy as the reference standard. However, microscopy-discordant results were shown to be positive for P. falciparum by PCR in all cases, suggesting that the PPV was in fact higher. CONCLUSION The pLDH antigen on three-band RDTs, used in combination with HRP2, provides added diagnostic specificity for malaria parasitaemia and may be useful to distinguish acute infection from recently treated infection. In situations where diagnostic specificity is desirable (e.g., for selection of malaria-infected participants in clinical trials), a three-band RDT should be considered in a sub-Saharan African setting.
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Affiliation(s)
| | | | | | | | | | | | - Kevin C Kain
- Department of Medicine, University of Toronto, Toronto, Canada.
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Stevenson JC, Stresman GH, Gitonga CW, Gillig J, Owaga C, Marube E, Odongo W, Okoth A, China P, Oriango R, Brooker SJ, Bousema T, Drakeley C, Cox J. Reliability of school surveys in estimating geographic variation in malaria transmission in the western Kenyan highlands. PLoS One 2013; 8:e77641. [PMID: 24143250 PMCID: PMC3797060 DOI: 10.1371/journal.pone.0077641] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/12/2013] [Indexed: 11/25/2022] Open
Abstract
Background School surveys provide an operational approach to assess malaria transmission through parasite prevalence. There is limited evidence on the comparability of prevalence estimates obtained from school and community surveys carried out at the same locality. Methods Concurrent school and community cross-sectional surveys were conducted in 46 school/community clusters in the western Kenyan highlands and households of school children were geolocated. Malaria was assessed by rapid diagnostic test (RDT) and combined seroprevalence of antibodies to bloodstage Plasmodium falciparum antigens. Results RDT prevalence in school and community populations was 25.7% (95% CI: 24.4-26.8) and 15.5% (95% CI: 14.4-16.7), respectively. Seroprevalence in the school and community populations was 51.9% (95% CI: 50.5-53.3) and 51.5% (95% CI: 49.5-52.9), respectively. RDT prevalence in schools could differentiate between low (<7%, 95% CI: 0-19%) and high (>39%, 95% CI: 25-49%) transmission areas in the community and, after a simple adjustment, were concordant with the community estimates. Conclusions Estimates of malaria prevalence from school surveys were consistently higher than those from community surveys and were strongly correlated. School-based estimates can be used as a reliable indicator of malaria transmission intensity in the wider community and may provide a basis for identifying priority areas for malaria control.
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Affiliation(s)
- Jennifer C. Stevenson
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Gillian H. Stresman
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Caroline W. Gitonga
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Malaria Public Health Department, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Jonathan Gillig
- Eck Institute for Global Health, University of Notre Dame, South Bend, Indiana, United States of America
| | - Chrispin Owaga
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Elizabeth Marube
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Wycliffe Odongo
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Albert Okoth
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Pauline China
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Robin Oriango
- Center for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Simon J. Brooker
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Malaria Public Health Department, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jonathan Cox
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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