Investigation of a leptospirosis outbreak in triathlon participants, Réunion Island, 2013

Abstract

We report herein the investigation of a leptospirosis outbreak occurring in triathlon competitors on Réunion Island, Indian Ocean. All participants were contacted by phone or email and answered a questionnaire. Detection and molecular characterization of pathogenic Leptospira was conducted in inpatients and in rodents trapped at the vicinity of the event. Of the 160 athletes competing, 101 (63·1%) agreed to participate in the study. Leptospirosis was biologically confirmed for 9/10 suspected cases either by real-time PCR or serological tests (MAT or ELISA). The total attack rate, children's attack rate, swimmers' attack rate, and the attack rate in adult swimmers were respectively estimated at 8·1% [95% confidence interval (CI) 4·3-14·7], 0%, 12·7% (95% CI 6·8-22·4) and 23·1% (95% CI 12·6-33·8). Leptospirosis cases reported significantly more wounds [risk ratio (RR) 4·5, 95% CI 1·6-13], wore complete neoprene suits less often (RR 4·3, 95% CI 1·3-14·5) and were most frequently unlicensed (RR 6·6, 95% CI 2·9-14·8). The epidemiological investigation supported that some measures such as the use of neoprene suits proved efficient in protecting swimmers against infection. PCR detection in rats revealed high Leptospira infection rates. Partial sequencing of the 16S gene and serology on both human and animal samples strongly suggests that rats were the main contaminators and were likely at the origin of the infection in humans.

Multi-locus sequence analyses reveal a clonal L. borgpetersenii genotype in a heterogeneous invasive Rattus spp. community across the City of Johannesburg, South Africa

“…varies widely in Africa (4), the prevalence (44%, 75/171) identi ed here, and in a previous study undertaken in Cape Town (7), are amongst the highest identi ed in similar contexts in the region. For example, the prevalence noted in this surveillance study is similar to that identi ed in surveillance-based sampling undertaken in urban Antananarivo in Madagascar (49%, 47/96) (26) while the prevalence (67%, 8/12) identi ed in R. norvegicus during an outbreak in Cape Town (7) is similar to that identi ed during an outbreak investigation (68%, 17/25) undertaken in Reunion Island (27).…”

Muskrats are greater carriers of pathogenic Leptospira than coypus in ecosystems with temperate climates

“…Leptospirosis outbreaks have previously been associated with recreational activities (canoeing, kayaking, water rafting, triathlon, and swimming) that bring people into close contact with water contaminated with pathogenic leptospires [6,7]. The climatic conditions in intertropical zones promote outbreak events [8,9]. In temperate zones such as Western Europe, leptospirosis outbreaks were rare in previous decades and were generally limited in their extent [10].…”

Leptospirosis among Returned Travelers: A GeoSentinel Site Survey and Multicenter Analysis—1997–2016

“…With increasing popularity of tourism in tropical areas, 32 including active, environmental exposures like rafting, canoeing, and triathlons, the risk of leptospirosis acquisition among travelers may be increasing, as illustrated in previous case reports. 37,41,42 Known high-risk areas, such as Southeast Asia and Central America, were the most common regions of exposure in our database. The top countries where leptospirosis was acquired, Thailand, Costa Rica and Laos, are not necessarily known to be most endemic, 1,43 but rather have higher numbers of travelers who are potentially engaged in freshwater recreational activities.…”