Severe community-acquired Acinetobacter baumannii pneumonia: An emerging highly lethal infectious disease in the Asia–Pacific

Background and objective:  Patients with community-acquired Acinetobacter baumannii (AB) pneumonia have been reported from subtropical countries. We investigated the epidemiology, clinical and microbiological characteristics of community-acquired pneumonia (CAP) due to AB in Singapore. Method:  A retrospective case series was performed over a 21-month period at two institutions. Results:  From 1 January 2007 to 30 September 2008, eight patients were diagnosed with CAP due to AB. Seven had bacteraemia and five were sputum culture-positive. The median age at presentation was 58.5 years (range 45–76 years). Five patients (71.4%) acquired the pneumonia in the warmer months of June to September. Presentation was acute, with a median duration of 2.5 days (range 1–7 days). The median Acute Physiology and Chronic Health Evaluation II score was 28.5 (range 6–36). Six patients presented with septic shock, lactic acidosis, acute kidney injury and respiratory failure, necessitating ICU care; five of thesepatients eventually died. All patients received empirical antibiotics, including third-generation cephalosporins, which were inactive against the organism. All isolates were susceptible to ampicillin/sulbactam, ciprofloxacin, co-trimoxazole, aminoglycosides and imipenem. Conclusions:  Community-acquired AB pneumonia have a fulminant course. In a region endemic for melioidosis and severe community-acquired Klebsiella pneumoniae, the challenge lies in rapid identification and initiation of appropriate empirical antibiotics to improve the survival of patients with AB CAP.