The changing burden of malaria in sub-Saharan Africa
The coast of Kenya experienced declining malaria morbidity for over a decade. Careful examination of hospital records over 20 years allowed us to document for the first time changes in the epidemiology of severe malaria under declining transmission. Our work showed that the first evidence of changing transmission was an increase in the mean age of afflicted children, which preceded any reduction in disease burden by more than five years. These findings have since been confirmed in several other settings. However, we could not attribute the decline in transmission to specific interventions. This led us to review changes in malaria burden and intervention coverage across sub-Saharan Africa. We found several examples of temporal dissociation between changes in malaria burden and scale-up of intervention coverage.
Measuring the impact of malaria control is essential for mapping progress towards elimination but is extremely difficult in countries where health information systems are weak. Furthermore, malaria transmission becomes more heterogeneous as transmission declines, requiring more finely grained information than country-level trends or individual sentinel sites. Our goal is to develop tools that can identify a breakdown in the efficacy of malaria prevention strategies before an up-tick in malaria burden. These tools must be rapid, community-based, and locally deploy-able in order to be effective and must include entomological, environmental, behavioral, and biological components.
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- W. P. O’Meara, J. Mangeni, R. Steketee, B. Greenwood, “The changing burden of malaria in Sub-Saharan Africa” Lancet Infectious Diseases 10(8): 545-555 (2010)
- W. P. O’Meara, P. Bejon, T. W. Mwangi, E. Okiro, N. Peshu, R. W. Snow, C. Newton, K. Marsh, “Effect of a fall in malaria transmission on morbidity and mortality in Kiliﬁ, Kenya” Lancet 372:1555-1562 (2008)
- W. P. O’Meara, T. Mwangi, T. Williams, F.E. McKenzie, R. Snow, K. Marsh “Relationship between exposure, clinical malaria and age in an area of changing transmission intensity” American Journal of Tropical Medicine and Hygiene 79(2):185-191 (2008).
- J.N. Mangeni, D. Menya, A.A. Obala, A. Platt, W. P. O’Meara, “Development and piloting of an evidence-based rapid assessment tool for malaria prevention”, Malaria Journal 15:544 (2016)