Community-acquired pneumonia in the central desert and north-western tropics of Australia

Background: Community-acquired pneumonia (CAP) results in significant morbidity in central and north-western Australia. However, the nature, management and outcome of CAP are poorly documented. The aim of the study was to describe CAP in the Kimberley and Central Desert regions of Australia. Methods: Prospective and retrospective cohort studies of inpatient management of adults with CAP at Alice Springs Hospital and six Kimberley hospitals were carried out. We documented demographic data, comorbidities, investigations, causes, CAP severity, outcome and concordance between prescribed and protocol-recommended antibiotics. Results: Two hundred and ninety-three subjects were included. Aboriginal Australians were overrepresented (relative risk 8.1). Patients were notably younger (median age 44.5 years) and disease severity lower than in urban Australian settings. Two patients died within 30 days of admission compared with expected mortality based on Pneumonia Severity Index predictions of seven deaths (κ ², P = 0.09). Disease severity and outcome did not differ between regions. Management differences were identified, including significantly more investigations, higher rates of critical care and broader antibiotic cover in Central Australia compared with the Kimberley. Sputum culture results showed Gram-negative organisms in both regions. However, Streptococcus pneumoniae was the most frequent organism isolated in the Kimberley and Haemophilus influenzae in Central Australia. Conclusion: CAP in this setting is an Aboriginal health issue. The low mortality observed and results of microbiology investigations support the use of existing antibiotic protocols. Larger studies investigating CAP aetiology are warranted. Addressing social and environmental disadvantage remains the key factors in dealing with the burden of CAP in this setting.