A case-control study of community-acquired Acinetobacter baumannii pneumonia and melioidosis pneumonia in northeast Thailand: an emerging fatal disease with unique clinical features.

Acinetobacter baumannii is the emerging cause of severe and often fatal gram-negative, community-acquired pneumonia (CAP-AB) in Thailand. Due to its rarity, its specific clinical features are ill defined. In this retrospective study, we compared the demographic data, risk factors, clinical characteristics, radiographic pattern, and microbiological data between CAP-AB and Burkholderia pseudomallei CAP (CAP-BP) to identify the clinical features and risk factors of CAP-AB. CAP-AB was associated with a more productive cough and a shorter duration of symptoms, while CAP-BP was associated with more musculoskeletal symptoms. The white blood cell and neutrophil counts were significantly lower in the CAP-AB group. Gram staining of the sputum revealed a significantly higher amount of bacteria in the CAP-AB group. Lobar infiltration and unilateral right lung involvement were the most common radiographic patterns in the CAP-AB group. CAP-AB is associated with severe pneumonia and has unique clinical features that distinguish it from CAP-BP.