Etiology and epidemiology of community-acquired pneumonia in adults requiring hospital admission: A prospective study in rural Central Philippines

Background: Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality among adults worldwide. However, the distribution of the etiology of CAP varies from one country to another, with limited data from rural areas. Methods: A prospective hospital-based study on adult CAP was conducted in Leyte, Central Philippines from May 2010 to May 2012. Blood, sputum, and nasopharyngeal samples obtained from patients were used to identify pathogens using standard microbiological culture methods and PCR. Results: Of the 535 patients enrolled, 38% were younger than 50 years old. More than half of the patients had an underlying disease, including pulmonary tuberculosis (22%). The detection rate was higher for bacteria (40%) than viruses (13%). Haemophilus influenzae (12%) was the most commonly detected bacterium and influenza virus (5%) was the most commonly detected virus. The proportion of CAP patients with Mycobacterium tuberculosis infection was higher in the younger age group than in the older age group. Among CAP patients, 14% died during hospitalization, and drowsiness on admission and SpO ₂ <90% were independent risk factors for mortality. Conclusions: Bacterial infections contribute substantially to the number of hospitalizations among CAP patients in rural Philippines. This study also highlights the importance of treatment of tuberculosis in reducing the burden of adult CAP in the country.