Changing malaria intervention coverage, transmission and hospitalization in Kenya

Area of Science:

• Epidemiology
• Public Health
• Malariology

Background:

• Reports indicate a transition in malaria epidemiology across Africa, with declining disease burden in some regions.
• The direct impact of scaled-up interventions on this epidemiological transition remains uncertain.

Purpose of the Study:

• To analyze changes in pediatric malaria hospitalization rates in Kenya before and after scaled intervention implementation.
• To identify potential drivers influencing temporal trends in malaria incidence.

Main Methods:

• Paediatric admission data from eight Kenyan hospitals (2003-2009) were analyzed using interrupted time series (ITS) models.
• Models adjusted for rainfall and community hospital use to assess changes in malaria hospitalization.
• Temporal factors were examined, compared, and ranked for explanatory power.

Main Results:

• Six out of eight sites showed a decline in malaria admission rates (18%-69%); two sites saw increases (35%-55%).
• ITS models indicated significant declines in malaria admissions at four sites post-intervention.
• Changes in trends varied by site; rainfall and insecticide-treated net (ITN) coverage partially explained variations.

Conclusions:

• Significant heterogeneity exists in malaria disease burden trends within and between locations in Kenya.
• Complex, retrospectively difficult-to-measure mechanisms likely drive changes in malaria incidence.