Leptospirosis Seroconversion Surveillance Among US Marines Assigned to Japan, 2011–2015

Abstract

Abstract Introduction: Leptospirosis is a global zoonotic disease spread through contact with contaminated water/soil. The US soldiers at the military bases in these countries are extremely vulnerable, as most of them are immunologically naïve to the responsible pathogen. No recent sero-epidemiological data of leptospirosis among US Marines stationed in Japan were available. Materials and Methods: In this study, we analyzed the presence of leptospirosis in US Marines stationed in Japan. One thousand posttour sera samples were analyzed by enzyme-linked immunosorbent assay for Leptospira-specific Immunoglobulin G. Results: Among these 1,000 posttour samples, 85 of them were positive and corresponding pretour samples were analyzed by enzyme-linked immunosorbent assay also. Seroconversion occurred for 35 (3.5%) Marines during their assignment to Japan. These results also indicate that 50 Marine personnels were exposed to leptospires before their assignment to Japan, perhaps because of previous exposure to leptospires at home. Conclusion: The 5% rate of seroconversion in 2013 and 2014 suggests that leptospirosis is a potential threat for Marines in the endemic region in Japan.