Objective: To determine the clinical presentations, radiographic chest findings, and their correlation in patients with leptospirosis.
Design: A cross sectional study.
Setting: Between July 2001- December 2002 at 3 hospitals in North Eastern Thailand.
Material and Method: Two hundred and forty patients with laboratory confirmed leptospirosis.
Results: Two hundred and nine (87.1%) patients were males. The mean age was 37.53 years (range 13-76). The median duration of fever was 3 days (range 1-13). Overall, 154 patients (64.2%) had respiratory symptoms and 26 (10.8%) patients had hemoptysis. Jaundice was detected in 76 (31.7%) patients, hypotension in 50 (20.8%), renal dysfunction in 80 (30%), and multiorgan dysfunction in 62 (25.8%) on admission. One hundred and fifty-four (64.17%) patients had abnormal chest radiographs on admission (classified as cardiovascular, pulmonary, and mixed cardio-pulmonary involvement in 40 (25.97%), 41 (26.62%), and 73 (47.4%) patients, respectively). Jaundice was significantly associated with the likelihood of having abnormal chest radiography on admission. Air- space nodules detected on the chest radiograph were significantly more common in patients with renal dysfunction and patients who required mechanical ventilation.
Conclusion: Pulmonary and cardiovascular involvements are common in leptospirosis. Air-space nodules detected by chest radiography may indicate severe leptospirosis.

Keywords: Leptospirosis, Chest radiograph, Pulmonary