OA Epidemiology

Identification of Hotspots of Malaria Transmission; Paving the Road for Targeted and Effective Intervention Strategies

Proceedings of the 2013 annual meeting of the Netherlands Epidemiology Society

Volume 1 Issue S1 Abstract 9

 

Amrish Y. Baidjoe, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
Jennifer Stevenson, London School of Hygiene and Tropical Medicine, London
Gillian Stresman, London School of Hygiene and Tropical Medicine, London
Will Stone, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
Chrispin Owaga, Kenya Medical Research Institute, Kisumu, Kenya
Euniah Makori, Kenya Medical Research Institute, Kisumu, Kenya
Shehu Shagari, Kenya Medical Research Institute, Kisumu, Kenya
Pauline China, Kenya Medical Research Institute, Kisumu, Kenya
Wycliffe Odongo, Kenya Medical Research Institute, Kisumu, Kenya
Robert Sauwerwein, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
Chris Drakeley, London School of Hygiene and Tropical Medicine, London
Jonathan Cox, London School of Hygiene and Tropical Medicine, London
Teun Bousem, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands

Background
Malaria risk is not uniformly distributed between districts, villages and
even households from the same village. Whilst mean levels of malaria transmission may decline in an area, strongholds of intense transmission may persist. In the highlands of western Kenya, malaria transmission is highly variable despite universal high coverage rates with insecticide treated nets (ITNs) and indoor residual spraying (IRS). The extent to which heterogeneity has an impact on effective malaria control remains unknown.

Methods
We identified micro-epidemiological patterns in malaria transmission in a
large cross-sectional survey. We collected blood samples from 17506 individuals residing in 3,218 compounds, distributed over an area of 100km2. GPS coordinates of every household were recorded. Hotspots of malaria transmission were identified by determining spatial patterns in the prevalence of P. falciparum  parasites, determined by PCR analyses and serological markers of malaria exposure.

Results
Spatial clustering based on PCR analyses (23% positive, 95% CI 22.1-
24.0%) and serological markers of malaria exposure based on the levels of AMA-1 (44.4%, 95% CI 43.6-45.2%)  and MSP-119 (34.4%, 95% CI 33.7-35.1%)  revealed hotspots of intense malaria transmission. 29.3% of the people  (95% CI 28.7-30.0%) lives inside hotspots of more intense malaria. Hotspots were not only located around rivers and persistent water bodies but also around less intuitive places.

Conclusions
We identified areas of persistent malaria prevalence in the low transmission season. These ‘hotspots’ of malaria were used for a targeted intervention strategy which is currently under evaluation. Results of the survey and the intervention will be presented.

Published: 06 Jun, 2013

 
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)