Geographical patterns of malaria transmission based on serological markers for falciparum and vivax malaria in Ratanakiri, CambodiaReport as inadecuate




Geographical patterns of malaria transmission based on serological markers for falciparum and vivax malaria in Ratanakiri, Cambodia - Download this document for free, or read online. Document in PDF available to download.

Malaria Journal

, 15:510

First Online: 19 October 2016Received: 28 July 2016Accepted: 07 October 2016DOI: 10.1186-s12936-016-1558-1

Cite this article as: Kerkhof, K., Sluydts, V., Heng, S. et al. Malar J 2016 15: 510. doi:10.1186-s12936-016-1558-1

Abstract

BackgroundMalaria transmission is highly heterogeneous, especially in low endemic countries, such as Cambodia. This results in geographical clusters of residual transmission in the dry, low transmission season, which can fuel the transmission to wider areas or populations during the wet season. A better understanding of spatial clustering of malaria can lead to a more efficient, targeted strategy to reduce malaria transmission. This study aims to evaluate the potential of the use of serological markers to define spatial patterns in malaria exposure.

MethodsBlood samples collected in a community-based randomized trial performed in 98 high endemic communities in Ratanakiri province, north-eastern Cambodia, were screened with a multiplex serological assay for five serological markers three Plasmodium falciparum and two Plasmodium vivax. The antibody half-lives range from approximately six months until more than two years. Geographical heterogeneity in malaria transmission was examined using a spatial scan statistic on serology, PCR prevalence and malaria incidence rate data. Furthermore, to identify behavioural patterns or intrinsic factors associated with malaria exposure antibody levels, risk factor analyses were performed by using multivariable random effect logistic regression models. The serological outcomes were then compared to PCR prevalence and malaria incidence data.

ResultsA total of 6502 samples from two surveys were screened in an area where the average parasite prevalence estimated by PCR among the selected villages is 3.4 %. High-risk malaria pockets were observed adjacent to the ‘Tonle San River’ and neighbouring Vietnam for all three sets of data serology, PCR prevalence and malaria incidence rates. The main risk factors for all P. falciparum antigens and P. vivax MSP1.19 are age, ethnicity and staying overnight at the plot hut.

ConclusionIt is possible to identify similar malaria pockets of higher malaria transmission together with the potential risk factors by using serology instead of PCR prevalence or malaria incidence data. In north-eastern Cambodia, the serological markers show that malaria transmission occurs mainly in adults staying overnight in plot huts in the field. Pf.GLURP.R2 showed a shrinking pocket of malaria transmission over time, and Pf.MSP1.19, CSP, PvAMA1 were also informative for current infection to a lesser extent. Therefore, serology could contribute in future research. However, further in-depth research in selecting the best combination of antigens is required.

KeywordsMalaria Serological markers Geographical patterns Malaria pockets Heterogeneous transmission Cambodia Electronic supplementary materialThe online version of this article doi:10.1186-s12936-016-1558-1 contains supplementary material, which is available to authorized users.

Download fulltext PDF



Author: Karen Kerkhof - Vincent Sluydts - Somony Heng - Saorin Kim - Myrthe Pareyn - Laura Willen - Lydie Canier - Siv Sovannaroth

Source: https://link.springer.com/







Related documents