Legionnaires’ Disease Caused by Legionella pneumophila Serogroups 5 and 10, China (http://wwwnc.cdc.gov/eid/article/20/7/13-1343)

摘要

To the Editor: Legionnaires’ disease is a systemic infection caused by gram-negative bacteria belonging to the genus Legionella. The primary clinical manifestation is pneumonia. Legionella spp. are typically found in natural and artificially hydrated environments. Legionella pneumophila is the species responsible for ≈90% of human cases of infection. L. pneumophila is divided into 15 serogroups, among which serogroup 1 is the most prevalent disease-causing variant (1). In contrast, rare cases are caused by other serogroups. We describe a case of Legionnaires’ disease caused by co-infection with L. pneumophila serogroups 5 and 10 and the genotype characteristics of these strains. The case-patient was a 77-yearold man who had chronic hepatitis B for 50 years, ankylosing spondylitis for 40 years, and chronic cholecystitis for 5 years. On September 17, 2012, he was admitted to Wuxi People’s Hospital (Wuxi, China) for treatment after a continuous cough for 15 days and a high fever for 2 days. At admission, the patient had a blood pressure of 130/65 mm Hg, a pulse rate of 102 beats/minute, and a body temperature of 37.4°C, which increased to 38.4°C four hours later. Laboratory tests showed a leukocyte count of 9,200 cells/μL (88.7% neutrophils) and a C-reactive protein level of 31 mg/L in serum. Lung inflammation was identified by computed tomography. The result of a urinary antigen test for L. pneumophila serogroup 1 (Binax, Portland, ME, USA) was negative. Bronchoalveolar lavage was performed, and fluid was collected for bacterial culture and molecular analysis.