The epidemiology of hospitalized pneumonia in rural Kenya: the potential of surveillance data in setting public health priorities

Introduction: Surveillance data from inpatient health facilities can be useful for prioritization of public health initiatives, but often are not collected or analyzed in developing countries. We evaluated data on hospitalized patients diagnosed with pneumonia in rural western Kenya to characterize pneumonia epidemiology and mortality. Methods: Data were obtained from admission registers of all inpatient facilities from 2001 to 2003 in Bondo District (estimated 2003 population: 255901), which is holoendemic for malaria and has high HIV rates. Inpatients with diagnoses compatible with acute pneumonia were included, and census data (1999) were used to calculate incidence rates by age, sex, season, and residence. Results: From 2001 to 2003, a total of 2466 patients diagnosed with pneumonia were hospitalized with 282 deaths (11.4%). Incidence peaked at 698 per 100 000 person-years among children <5 years of age. A second peak occurred among 20-29 year-olds at 356 per 100 000 person-years; rates were twice as high in women as men in this age group (p < 0.001). The incidence in persons >65 years was 121 per 100 000 person-years. Pneumonia incidence peaked during the twice-yearly high malaria seasons, 1-2 months after peak rainfall. Rates of pneumonia decreased with increasing distance of residence from the district hospital (p < 0.0001). Discussion: In Bondo District, the pneumonia burden is greatest among young children and middle-aged adults, the latter peak reflecting the area's HIV epidemic. Access to care likely influenced hospital utilization and thus pneumonia rates, particularly among the elderly. Our findings show that hospital-based data can provide useful information for public health priority setting, such as the introduction of new pneumonia vaccines for children and accelerating the introduction of antiretroviral medications.