Risk of Legionnaires' Disease from Cleaning Grease Traps

A 61-year-old man presented with a 3-days' history of fever and headache. On admission, his body temperature was 40°C, pulse rate was 99/min, and respiratory rate was 25/min. Serum CRP was elevated, and chest X-ray showed an opacity in the left upper lung field. Under the suspected diagnosis of community-acquired pneumonia, the patient was initiated on treatment with ampicillin/sulbactam, and oxygen supplementation via a nasal cannula at 2L/min. A review of the history revealed that his current occupation was maintenance of grease traps, which are chambers for removing grease from food waste before it enters the sewer pipe. Four days before onset of his symptoms, he had worked on a very dirty restaurant grease trap while wearing a poorly equipped face mask. Legionnaires' disease was suspected, and urinary antigen testing revealed a positive result. Sputum culture and PCR were also positive for Legionella pneumophila serogroup 1, the most common causative Legionella genus of acute pneumonic illness. The antibiotic was switched to intravenous levofloxacin at 500mg/day on day 2 of admission, and the patient's symptoms improved.