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 these patients 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.