Research

The decline in paediatric malaria admissions on the coast of Kenya

Emelda A Okiro¹ , Simon I Hay^1,2 , Priscilla W Gikandi¹ , Shahnaaz K Sharif³ , Abdisalan M Noor¹ , Norbert Peshu⁴ , Kevin Marsh^4,5 and Robert W Snow^1,5

¹Malaria 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

²Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK

³Ministry of Health, Afya House, Cathedral Road, P.O. Box 30016, 00100 GPO, Nairobi, Kenya

⁴Centre for Geographic Medicine – Coast, Kenya Medical Research Institute, P.O. Box 230, Kilifi, Kenya

⁵Centre for Tropical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK

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Malaria Journal 2007, 6:151doi:10.1186/1475-2875-6-151

Published:	15 November 2007

Abstract

Background

There is only limited information on the health impact of expanded coverage of malaria control and preventative strategies in Africa.

Methods

Paediatric admission data were assembled over 8.25 years from three District Hospitals; Kilifi, Msambweni and Malindi, situated along the Kenyan Coast. Trends in monthly malaria admissions between January 1999 and March 2007 were analysed using several time-series models that adjusted for monthly non-malaria admission rates and the seasonality and trends in rainfall.

Results

Since January 1999 paediatric malaria admissions have significantly declined at all hospitals. This trend was observed against a background of rising or constant non-malaria admissions and unaffected by long-term rainfall throughout the surveillance period. By March 2007 the estimated proportional decline in malaria cases was 63% in Kilifi, 53% in Kwale and 28% in Malindi. Time-series models strongly suggest that the observed decline in malaria admissions was a result of malaria-specific control efforts in the hospital catchment areas.

Conclusion

This study provides evidence of a changing disease burden on the Kenyan coast and that the most parsimonious explanation is an expansion in the coverage of interventions such as the use of insecticide-treated nets and the availability of anti-malarial medicines. While specific attribution to intervention coverage cannot be computed what is clear is that this area of Kenya is experiencing a malaria epidemiological transition.