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Ohene-Adjei K, Asante KP, Akuffo KO, Tounaikok N, Asiamah M, Owiredu D, Manu AA, Danso-Appiah A. Malaria vaccine-related adverse events among children under 5 in sub-Saharan Africa: systematic review and meta-analysis protocol. BMJ Open 2023; 13:e076985. [PMID: 37793915 PMCID: PMC10551995 DOI: 10.1136/bmjopen-2023-076985] [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] [Received: 06/22/2023] [Accepted: 09/11/2023] [Indexed: 10/06/2023] Open
Abstract
INTRODUCTION The RTS,S vaccine has been approved for use in children under 5 living in moderate to high malaria transmission areas. However, clinically important adverse events have been reported in countries in sub-Saharan Africa. This systematic review aims to assess the frequency, severity and clinical importance of vaccine-related adverse events. METHODS AND ANALYSIS This systematic review protocol has been prepared following robust methods and reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses for protocols guidelines. We will search PubMed, CINAHL, LILACS, Google Scholar, SCOPUS, WEB OF SCIENCE, Cochrane library, HINARI, African Journals Online, Trip Pro and TOXNET from 2000 to 30 September 2023, without language restrictions. We will also search conference proceedings, dissertations, World Bank Open Knowledge Repository, and WHO, PATH, UNICEF, Food and Drugs Authorities and European Medicines Agency databases, preprint repositories and reference lists of relevant studies for additional studies. Experts in the field will be contacted for unpublished or published studies missed by our searches. At least two reviewers will independently select studies and extract data using pretested tools and assess risk of bias in the included studies using the Cochrane risk of bias tool. Any disagreements will be resolved through discussion between the reviewers. Heterogeneity will be explored graphically, and statistically using the I2 statistic. We will conduct random-effects meta-analysis when heterogeneity is appreciable, and express dichotomous outcomes (serious adverse events, cerebral malaria and febrile convulsion) as risk ratio (RR) with their 95% CI. We will perform subgroup analysis to assess the impact of heterogeneity and sensitivity analyses to test the robustness of the effect estimates. The overall level of evidence will be assessed using Grading of Recommendations Assessment, Development and Evaluation. ETHICS AND DISSEMINATION Ethical approval is not required for a systematic review. The findings of this study will be disseminated through stakeholder forums, conferences and peer-review publications. PROSPERO REGISTRATION NUMBER CRD42021275155.
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Affiliation(s)
- Kennedy Ohene-Adjei
- Department of Epidemiology and Disease Control, School of Public Health, College of Health Sciences, University of Ghana, Accra, Ghana
- Tain District Health Directorate, Ghana Health Service, Tain, Ghana
| | - Kwaku Poku Asante
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo, Kintampo North Municipality, Bono East Region, Ghana
| | - Kwadwo Owusu Akuffo
- Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Narcisse Tounaikok
- Centre for Evidence Synthesis and Policy, School of Public Health, University of Ghana, Accra, Ghana
- Department of Human and Animal Health, University of Emi Koussi, N'Djamena, Chad
| | - Morrison Asiamah
- Department of Electron Microscopy and Histopathology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - David Owiredu
- Department of Epidemiology and Disease Control, School of Public Health, College of Health Sciences, University of Ghana, Accra, Ghana
- Centre for Evidence Synthesis and Policy, School of Public Health, University of Ghana, Accra, Ghana
| | - Alexander Ansah Manu
- Department of Epidemiology and Disease Control, School of Public Health, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Anthony Danso-Appiah
- Department of Epidemiology and Disease Control, School of Public Health, College of Health Sciences, University of Ghana, Accra, Ghana
- Centre for Evidence Synthesis and Policy, School of Public Health, University of Ghana, Accra, Ghana
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San NN, Kien NX, Manh ND, Van Thanh N, Chavchich M, Binh NTH, Long TK, Edgel KA, Rovira-Vallbona E, Edstein MD, Martin NJ. Cross-sectional study of asymptomatic malaria and seroepidemiological surveillance of seven districts in Gia Lai province, Vietnam. Malar J 2022; 21:40. [PMID: 35135536 PMCID: PMC8822839 DOI: 10.1186/s12936-022-04060-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/23/2022] [Indexed: 11/12/2022] Open
Abstract
Background Malaria elimination by 2030 is an aim of many countries in the Greater Mekong Sub-region, including Vietnam. However, to achieve this goal and accelerate towards malaria elimination, countries need to determine the extent and prevalence of asymptomatic malaria as a potential reservoir for malaria transmission and the intensity of malaria transmission. The purpose of this study was to determine the prevalence of asymptomatic malaria and seropositivity rate in several districts of Gia Lai province in the Central Highlands of Vietnam. Methods A cross-sectional survey of asymptomatic malaria and serological testing was conducted in 3283 people living at 14 communes across seven districts in Gia Lai province in December 2016 to January 2017. Finger prick capillary blood samples were tested for malaria using rapid diagnostic testing and polymerase chain reaction (PCR), as well as detecting antibodies against 3 Plasmodium falciparum and 4 Plasmodium vivax antigens by indirect enzyme-linked immunosorbent assay (ELISA). Age-seroprevalence curves were fitted using reverse catalytic models with maximum likelihood. Results The study population was predominantly male (65.9%, 2165/3283), adults (88.7%, 2911/3283) and of a minority ethnicity (72.2%, 2371/3283), with most participants being farmers and outdoor government workers (90.2%, 2960/3283). Using a small volume of blood (≈ 10 µL) the PCR assay revealed that 1.74% (57/3283) of the participants had asymptomatic malaria (P. falciparum 1.07%, P. vivax 0.40%, Plasmodium malariae 0.15% and mixed infections 0.12%). In contrast, the annual malaria prevalence rates for clinical malaria in the communities where the participants lived were 0.12% (108/90,395) in 2016 and 0.22% (201/93,184) in 2017. Seropositivity for at least one P. falciparum or one P. vivax antigen was 38.5% (1257/3262) and 31.1% (1022/3282), respectively. Age-dependent trends in the proportion of seropositive individuals in five of the districts discriminated the three districts with sustained low malaria prevalence from the two districts with higher transmission. Conclusions Asymptomatic Plasmodium carriers were found to be substantially more prevalent than clinical cases in seven districts of Gia Lai province, and a third of the population had serological evidence of previous malaria exposure. The findings add knowledge on the extent of asymptomatic malaria and transmission for developing malaria elimination strategies for Vietnam. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04060-6.
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Affiliation(s)
| | - Nguyen Xuan Kien
- Vietnam People's Army Military Medical Department, Hanoi, Vietnam
| | - Nguyen Duc Manh
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Nguyen Van Thanh
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Marina Chavchich
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | | | | | | | | | - Michael D Edstein
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
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Onohuean H, Alagbonsi AI, Usman IM, Iceland Kasozi K, Alexiou A, Badr RH, Batiha GES, Ezeonwumelu JOC. Annona muricata Linn and Khaya grandifoliola C.DC. Reduce Oxidative Stress In Vitro and Ameliorate Plasmodium berghei-Induced Parasitemia and Cytokines in BALB/c Mice. J Evid Based Integr Med 2021; 26:2515690X211036669. [PMID: 34350806 PMCID: PMC8358498 DOI: 10.1177/2515690x211036669] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background. Annona muricata and Khaya grandifoliola are ethnomedicinally used for the treatment of malaria and have been experimentally shown to have an anti-plasmodial effect, but the mechanisms involved are not fully understood. This study investigated the effect of the ethanol extracts of their leaves on parasitemia, radical scavenging and cytokines in Plasmodium berghei ANKA-infected BALB/c mice. Methods. BALB/c mice were infected with P. berghei and treated with chloroquine, A. muricata or K. grandifoliola extract for 4 days. The percentage of parasitemia and the level of cytokine expression were determined after treatment. Trace element, phytochemical and nitric oxide (NO) scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging properties assays were done to study the antioxidant effects of AN and KG in vitro. Results. P. berghei consistently increased parasitemia in BALB/c mice. The tested doses (100-, 200-, and 400 mg/kg) of A. muricata and K. grandifoliola attenuated the P. berghei-induced elevation of parasitemia and cytokines (TNF-α, IL-5, and IL-6) in vivo during the experimental period, though not as much as chloroquine. Moreover, both extracts scavenged the DPPH and NO radicals, though A. muricata had more anti-oxidant effect than K. grandifoliola in-vitro. Conclusion. The ethanol extracts of A. muricata and K. grandifoliola reduce parasitemia in P. berghei-treated mice BALB/c by scavenging free radicals and reducing cytokines, though the extracts were not as effective as chloroquine.
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Affiliation(s)
- Hope Onohuean
- Biomolecules, Metagenomics, Endocrine and Tropical Disease Research Group (BMETDREG), Kampala International University, Western Campus, Ishaka-Bushenyi, Uganda.,Biopharmaceutics Unit, Department of Pharmacology and Toxicology, Kampala International University Western Campus, Ishaka-Bushenyi, Uganda
| | - Abdullateef I Alagbonsi
- Physiology Unit, Department of Clinical Biology, School of Medicine and Pharmacy, University of Rwanda College of Medicine and Health Sciences, Huye, Republic of Rwanda
| | - Ibe M Usman
- Biomolecules, Metagenomics, Endocrine and Tropical Disease Research Group (BMETDREG), Kampala International University, Western Campus, Ishaka-Bushenyi, Uganda.,Department of Anatomy, Faculty of Biomedical Sciences, Kampala International University, Western Campus, Ishaka-Bushenyi, Uganda
| | | | - Athanasios Alexiou
- Novel Global Community Educational Foundation, Hebersham, New South Wales, Australia.,AFNP Med Austria, Wien, Austria
| | - Reem H Badr
- Department of Plant Physiology Botany and Microbiology, Faculty of Science, Alex University, Egypt
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, El Beheira, Egypt
| | - Joseph O C Ezeonwumelu
- Biomolecules, Metagenomics, Endocrine and Tropical Disease Research Group (BMETDREG), Kampala International University, Western Campus, Ishaka-Bushenyi, Uganda.,Department of Clinical Pharmacy and Biopharmacy, School of Pharmacy, Kampala International University, Western Campus, Ishaka-Bushenyi, Uganda
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Alegana VA, Suiyanka L, Macharia PM, Ikahu-Muchangi G, Snow RW. Malaria micro-stratification using routine surveillance data in Western Kenya. Malar J 2021; 20:22. [PMID: 33413385 PMCID: PMC7788718 DOI: 10.1186/s12936-020-03529-6] [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: 08/04/2020] [Accepted: 11/27/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is an increasing need for finer spatial resolution data on malaria risk to provide micro-stratification to guide sub-national strategic plans. Here, spatial-statistical techniques are used to exploit routine data to depict sub-national heterogeneities in test positivity rate (TPR) for malaria among patients attending health facilities in Kenya. METHODS Routine data from health facilities (n = 1804) representing all ages over 24 months (2018-2019) were assembled across 8 counties (62 sub-counties) in Western Kenya. Statistical model-based approaches were used to quantify heterogeneities in TPR and uncertainty at fine spatial resolution adjusting for missingness, population distribution, spatial data structure, month, and type of health facility. RESULTS The overall monthly reporting rate was 78.7% (IQR 75.0-100.0) and public-based health facilities were more likely than private facilities to report ≥ 12 months (OR 5.7, 95% CI 4.3-7.5). There was marked heterogeneity in population-weighted TPR with sub-counties in the north of the lake-endemic region exhibiting the highest rates (exceedance probability > 70% with 90% certainty) where approximately 2.7 million (28.5%) people reside. At micro-level the lowest rates were in 14 sub-counties (exceedance probability < 30% with 90% certainty) where approximately 2.2 million (23.1%) people lived and indoor residual spraying had been conducted since 2017. CONCLUSION The value of routine health data on TPR can be enhanced when adjusting for underlying population and spatial structures of the data, highlighting small-scale heterogeneities in malaria risk often masked in broad national stratifications. Future research should aim at relating these heterogeneities in TPR with traditional community-level prevalence to improve tailoring malaria control activities at sub-national levels.
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Affiliation(s)
- Victor A Alegana
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya. .,Geography and Environmental Science, University of Southampton, Southampton, SO17 1BJ, UK. .,Faculty of Science and Technology, Lancaster University, Lancaster, LAI 4YW, UK.
| | - Laurissa Suiyanka
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Peter M Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Grace Ikahu-Muchangi
- National Malaria Control Programme, Ministry of Health, P.O Box 30016-00100, Nairobi, Kenya
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7LJ, UK
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Leão L, Puty B, Dolabela MF, Povoa MM, Né YGDS, Eiró LG, Fagundes NCF, Maia LC, Lima RR. Association of cerebral malaria and TNF-α levels: a systematic review. BMC Infect Dis 2020; 20:442. [PMID: 32576141 PMCID: PMC7310527 DOI: 10.1186/s12879-020-05107-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 05/18/2020] [Indexed: 02/06/2023] Open
Abstract
Background Cerebral malaria is the most severe form of infection with Plasmodium falciparum characterized by a highly inflammatory response. This systematic review aimed to investigate the association between TNF-α levels and cerebral malaria. Methods This review followed the Preferred Reporting of Systematic Review and Meta-analyses (PRISMA) guidelines. The search was performed at PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey and Google Scholar. We have included studies of P. falciparum-infected humans with or without cerebral malaria and TNF-α dosage level. All studies were evaluated using a risk of bias tool and the GRADE approach. Results Our results have identified 2338 studies, and 8 articles were eligible according to this systematic review inclusion criteria. Among the eight articles, five have evaluated TNF- α plasma dosage, while two have evaluated at the blood and one at the brain (post-Morten). Among them, only five studies showed higher TNF-α levels in the cerebral malaria group compared to the severe malaria group. Methodological problems were identified regarding sample size, randomization and blindness, but no risk of bias was detected. Conclusion Although the results suggested that that TNF-α level is associated with cerebral malaria, the evidence is inconsistent and imprecise. More observational studies evaluating the average TNF-alpha are needed.
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Affiliation(s)
- Luana Leão
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 01 Augusto Correa Street, Guama, Belem, PA, 66075-900, Brazil
| | - Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 01 Augusto Correa Street, Guama, Belem, PA, 66075-900, Brazil
| | - Maria Fâni Dolabela
- Postgraduate Program in Pharmaceutical Sciences, Institute of Health Sciences, Federal University of Pará, Belém, Brazil
| | | | - Yago Gecy De Sousa Né
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 01 Augusto Correa Street, Guama, Belem, PA, 66075-900, Brazil
| | - Luciana Guimarães Eiró
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 01 Augusto Correa Street, Guama, Belem, PA, 66075-900, Brazil
| | | | - Lucianne Cople Maia
- Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 01 Augusto Correa Street, Guama, Belem, PA, 66075-900, Brazil.
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Mfueni E, Devleesschauwer B, Rosas-Aguirre A, Van Malderen C, Brandt PT, Ogutu B, Snow RW, Tshilolo L, Zurovac D, Vanderelst D, Speybroeck N. True malaria prevalence in children under five: Bayesian estimation using data of malaria household surveys from three sub-Saharan countries. Malar J 2018; 17:65. [PMID: 29402268 PMCID: PMC5800038 DOI: 10.1186/s12936-018-2211-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 01/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is one of the major causes of childhood death in sub-Saharan countries. A reliable estimation of malaria prevalence is important to guide and monitor progress toward control and elimination. The aim of the study was to estimate the true prevalence of malaria in children under five in the Democratic Republic of the Congo, Uganda and Kenya, using a Bayesian modelling framework that combined in a novel way malaria data from national household surveys with external information about the sensitivity and specificity of the malaria diagnostic methods used in those surveys-i.e., rapid diagnostic tests and light microscopy. METHODS Data were used from the Demographic and Health Surveys (DHS) and Malaria Indicator Surveys (MIS) conducted in the Democratic Republic of the Congo (DHS 2013-2014), Uganda (MIS 2014-2015) and Kenya (MIS 2015), where information on infection status using rapid diagnostic tests and/or light microscopy was available for 13,573 children. True prevalence was estimated using a Bayesian model that accounted for the conditional dependence between the two diagnostic methods, and the uncertainty of their sensitivities and specificities obtained from expert opinion. RESULTS The estimated true malaria prevalence was 20% (95% uncertainty interval [UI] 17%-23%) in the Democratic Republic of the Congo, 22% (95% UI 9-32%) in Uganda and 1% (95% UI 0-3%) in Kenya. According to the model estimations, rapid diagnostic tests had a satisfactory sensitivity and specificity, and light microscopy had a variable sensitivity, but a satisfactory specificity. Adding reported history of fever in the previous 14 days as a third diagnostic method to the model did not affect model estimates, highlighting the poor performance of this indicator as a malaria diagnostic. CONCLUSIONS In the absence of a gold standard test, Bayesian models can assist in the optimal estimation of the malaria burden, using individual results from several tests and expert opinion about the performance of those tests.
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Affiliation(s)
- Elvire Mfueni
- Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Brecht Devleesschauwer
- Department of Public Health and Surveillance, Scientific Institute of Public Health (WIV-ISP), Brussels, Belgium.
| | - Angel Rosas-Aguirre
- Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Carine Van Malderen
- Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Patrick T Brandt
- School of Economic, Political and Policy Sciences, The University of Texas, Dallas, TX, USA
| | | | - Robert W Snow
- Population & Health Theme, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Léon Tshilolo
- Centre Hospitalier Monkole, Kinshasa, Democratic Republic of the Congo
| | - Dejan Zurovac
- Population & Health Theme, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Dieter Vanderelst
- Department of Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Niko Speybroeck
- Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
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Ratmanov P, Mediannikov O, Raoult D. Vectorborne diseases in West Africa: geographic distribution and geospatial characteristics. Trans R Soc Trop Med Hyg 2013; 107:273-84. [PMID: 23479360 DOI: 10.1093/trstmh/trt020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This paper provides an overview of the methods in which geographic information systems (GIS) and remote sensing (RS) technology have been used to visualise and analyse data related to vectorborne diseases (VBD) in West Africa and to discuss the potential for these approaches to be routinely included in future studies of VBDs. GIS/RS studies of diseases that are associated with a specific geographic landscape were reviewed, including malaria, human African trypanosomiasis, leishmaniasis, lymphatic filariasis, Loa loa filariasis, onchocerciasis, Rift Valley fever, dengue, yellow fever, borreliosis, rickettsioses, Buruli ulcer and Q fever. RS data and powerful spatial modelling methods improve our understanding of how environmental factors affect the vectors and transmission of VBDs. There is great potential for the use of GIS/RS technologies in the surveillance, prevention and control of vectorborne and other infectious diseases in West Africa.
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Affiliation(s)
- Pavel Ratmanov
- Aix Marseille Université, URMITE, UMR CNRS 7278, IRD 198, INSERM 1095, 27 Boulevard Jean Moulin, 13385 Marseille cedex 05, France
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Epidemiology of malaria in endemic areas. Mediterr J Hematol Infect Dis 2012; 4:e2012060. [PMID: 23170189 PMCID: PMC3499992 DOI: 10.4084/mjhid.2012.060] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 09/21/2012] [Indexed: 11/08/2022] Open
Abstract
Malaria infection is still to be considered a major public health problem in those 106 countries where the risk of contracting the infection with one or more of the Plasmodium species exists. According to estimates from the World Health Organization, over 200 million cases and about 655.000 deaths have occurred in 2010. Estimating the real health and social burden of the disease is a difficult task, because many of the malaria endemic countries have limited diagnostic resources, especially in rural settings where conditions with similar clinical picture may coexist in the same geographical areas. Moreover, asymptomatic parasitaemia may occur in high transmission areas after childhood, when anti-malaria semi-immunity occurs. Malaria endemicity and control activities are very complex issues, that are influenced by factors related to the host, to the parasite, to the vector, to the environment and to the health system capacity to fully implement available anti-malaria weapons such as rapid diagnostic tests, artemisinin-based combination treatment, impregnated bed-nets and insecticide residual spraying while waiting for an effective vaccine to be made available.
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Taylor SM, Messina JP, Hand CC, Juliano JJ, Muwonga J, Tshefu AK, Atua B, Emch M, Meshnick SR. Molecular malaria epidemiology: mapping and burden estimates for the Democratic Republic of the Congo, 2007. PLoS One 2011; 6:e16420. [PMID: 21305011 PMCID: PMC3031549 DOI: 10.1371/journal.pone.0016420] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 12/15/2010] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Epidemiologic data on malaria are scant in many high-burden countries including the Democratic Republic of the Congo (DRC), which suffers the second-highest global burden of malaria. Malaria control efforts in regions with challenging infrastructure require reproducible and efficient surveillance. We employed new high-throughput molecular testing to characterize the state of malaria control in the DRC and estimate childhood mortality attributable to excess malaria transmission. METHODS AND FINDINGS The Demographic and Health Survey was a cross-sectional, population-based cluster household survey of adults aged 15-59 years in 2007 employing structured questionnaires and dried blood spot collection. Parasitemia was detected by real-time PCR, and survey responses measured adoption of malaria control measures and under-5 health indices. The response rate was 99% at the household level, and 8,886 households were surveyed in 300 clusters; from 8,838 respondents molecular results were available. The overall prevalence of parasitemia was 33.5% (95% confidence interval [C.I.] 32-34.9); P. falciparum was the most prevalent species, either as monoinfection (90.4%; 95% C.I. 88.8-92.1) or combined with P. malariae (4.9%; 95% C.I. 3.7-5.9) or P. ovale (0.6%; 95% C.I. 0.1-0.9). Only 7.7% (95% CI 6.8-8.6) of households with children under 5 owned an insecticide-treated bednet (ITN), and only 6.8% (95% CI 6.1-7.5) of under-fives slept under an ITN the preceding night. The overall under-5 mortality rate was 147 deaths per 1,000 live births (95% C.I. 141-153) and between clusters was associated with increased P. falciparum prevalence; based on the population attributable fraction, 26,488 yearly under-5 deaths were attributable to excess malaria transmission. CONCLUSIONS Adult P. falciparum prevalence is substantial in the DRC and is associated with under-5 mortality. Molecular testing offers a new, generalizable, and efficient approach to characterizing malaria endemicity in underserved countries.
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Affiliation(s)
- Steve M Taylor
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America.
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Abstract
In this introduction to volume 32 of Epidemiologic Reviews, the authors highlight the diversity and complexity of global health concerns, and they frame the 12 articles included in this issue within the diverse topics of research in this emerging and ever-expanding field. The authors emphasize the need for ongoing research related to the methods used in global health and for comprehensive surveillance, and they offer suggestions for future directions in global health research.
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Affiliation(s)
- Thomas C Quinn
- Johns Hopkins University Center for Global Health, Rangos Building, 855 North Wolfe Street, Suite 530, Baltimore, MD 21205, USA.
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