Establishing the extent of malaria transmission and challenges facing pre-elimination in the Republic of Djibouti

BMC Infectious Diseases

Research Article

Margaret J Mackinnon¹  Mary Nyonda¹  Christopher J Drakeley²  Jackie Cook²  Maoulid B Mohamed³  Cleopatra K Mugyenyi⁴  Caroline W Kabaria⁴  Robert W Snow⁵  Abdisalan M Noor⁵  Hawa H Guessod⁶  Mouna A Osman⁶  Ifrah A Ahmed⁶ 

[1] Centre for Geographic Medicine Research - Coast, Kenya Medical Research, Institute/Wellcome Trust Research Programme, P.O. Box 230, Kilifi, Kenya;Department of Immunity and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK;Direction de l'Epidémiologie et de l'Information Sanitaire, Ministère de la Sante, P.O. Box 438, Djibouti, Djibouti;Malaria Public Health & Epidemiology Group, Centre for Geographic Medicine Research - Coast, Kenya Medical Research Institute/Wellcome Trust Research Programme, P.O. Box 43640, 00100 GPO, Nairobi, Kenya;Malaria Public Health & Epidemiology Group, Centre for Geographic Medicine Research - Coast, Kenya Medical Research Institute/Wellcome Trust Research Programme, P.O. Box 43640, 00100 GPO, Nairobi, Kenya;Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, CCVTM, Oxford, UK;Programme National de Lutte Contre le Paludisme, Ministère de la Sante, P.O. Box 1157, Djibouti, Djibouti;

关键词: Malaria;    Malaria Transmission;    Parasite Prevalence;    Falciparum Infection;    Malaria Elimination;   

DOI  :  10.1186/1471-2334-11-121

 received in 2011-01-14, accepted in 2011-05-11,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundCountries aiming for malaria elimination require a detailed understanding of the current intensity of malaria transmission within their national borders. National household sample surveys are now being used to define infection prevalence but these are less efficient in areas of exceptionally low endemicity. Here we present the results of a national malaria indicator survey in the Republic of Djibouti, the first in sub-Saharan Africa to combine parasitological and serological markers of malaria, to evaluate the extent of transmission in the country and explore the potential for elimination.MethodsA national cross-sectional household survey was undertaken from December 2008 to January 2009. A finger prick blood sample was taken from randomly selected participants of all ages to examine for parasitaemia using rapid diagnostic tests (RDTs) and confirmed using Polymerase Chain Reaction (PCR). Blood spots were also collected on filter paper and subsequently used to evaluate the presence of serological markers (combined AMA-1 and MSP-119) of Plasmodium falciparum exposure. Multivariate regression analysis was used to determine the risk factors for P. falciparum infection and/or exposure. The Getis-Ord G-statistic was used to assess spatial heterogeneity of combined infections and serological markers.ResultsA total of 7151 individuals were tested using RDTs of which only 42 (0.5%) were positive for P. falciparum infections and confirmed by PCR. Filter paper blood spots were collected for 5605 individuals. Of these 4769 showed concordant optical density results and were retained in subsequent analysis. Overall P. falciparum sero-prevalence was 9.9% (517/4769) for all ages; 6.9% (46/649) in children under the age of five years; and 14.2% (76/510) in the oldest age group (≥ 50 years). The combined infection and/or antibody prevalence was 10.5% (550/4769) and varied from 8.1% to 14.1% but overall regional differences were not statistically significant (χ2 = 33.98, p = 0.3144). Increasing age (p < 0.001) and decreasing household wealth status (p < 0.001) were significantly associated with increasing combined P. falciparum infection and/or antibody prevalence. Significant P. falciparum hot spots were observed in Dikhil region.ConclusionMalaria transmission in the Republic of Djibouti is very low across all regions with evidence of micro-epidemiological heterogeneity and limited recent transmission. It would seem that the Republic of Djibouti has a biologically feasible set of pre-conditions for elimination, however, the operational feasibility and the potential risks to elimination posed by P. vivax and human population movement across the sub-region remain to be properly established.

【 授权许可】

CC BY   
© Noor et al; licensee BioMed Central Ltd. 2011