A comparison of population-based pneumonia surveillance and health-seeking behavior in two provinces in rural Thailand

OBJECTIVES: Pneumonia is a leading cause of death worldwide, but there are limited population-based data on the burden of disease. We sought to determine the incidence of pneumonia in rural Thailand. METHODS: Active, population-based surveillance for hospitalized, radiologically-confirmed pneumonia was conducted in two rural Thai provinces. Incidence rates were calculated using census data. Residents of each province were surveyed regarding healthcare utilization for pneumonia. Survey results were used to adjust the incidence of hospitalized pneumonia for incomplete use of hospital care. RESULTS: In the province of Nakhon Phanom, active surveillance identified 1457 radiologically-confirmed, hospitalized pneumonia cases during the period September 2003-August 2004. The unadjusted incidence was 201/100,000/year; adjusted for incomplete radiography, the incidence was 485/100,000/year. Incidence was highest in persons aged or=65 years (1573/100,000/year). The community survey found that 58% of persons with probable pneumonia reported seeking healthcare at hospital facilities. Adjusted for healthcare access, pneumonia incidence in Nakhon Phanom was 831/100,000/year, compared with 495/100,000/year in the province of Sa Kaeo during 2002-2003. CONCLUSIONS: The incidence of pneumonia in rural Thailand is high. Ongoing surveillance can guide and evaluate prevention strategies. Community surveys complement pneumonia surveillance data by providing a more complete estimate of disease burden.