A systematic literature review of leptospirosis outbreaks worldwide, 1970–2012

Abstract

Objective. This review describes the geographic and temporal distribution of, detection methods for, and other epidemiological features of published leptospirosis outbreaks, with the aim of informing efforts to standardize outbreak-reporting practices. Methods. We conducted a systematic review of leptospirosis outbreaks reported in the scientific literature and ProMED during 1970–2012. Predefined criteria were used to identify and classify outbreaks and a standard form was used to extract information. Results. During 1970–2012, we identified 318 outbreaks (average: 7 outbreaks/year; range: 1–19). Most outbreaks were reported in the Latin America and the Caribbean region (36%), followed by Southern Asia (13%), and North America (11%). Most outbreaks were located in tropical and subtropical ecoregions (55%). Quality classification showed that there was clear description of laboratory-confirmed cases in 40% of outbreaks. Among those, the average outbreak size was 82 cases overall (range: 2–2 259) but reached 253 cases in tropical/subtropical ecoregions. Common risk factors included outdoor work activities (25%), exposure to floodwaters (23%), and recreational exposure to water (22%). Epidemiologic investigation was conducted in 80% of outbreaks, mainly as case interviews. Case fatality was 5% overall (range: 0%–60%). Conclusions. Outbreak reporting increased over the study period with outbreaks covering tropical and non-tropical regions. Outbreaks varied by size, setting, and risk factors; however, data reviewed often had limited information regarding diagnosis and epidemiology. Guidelines are recommended to develop standardized procedures for diagnostic and epidemiological investigations during an outbreak and for reporting.

Epidemiology of human leptospirosis in urban and rural areas of Brazil, 2000–2015

“…Several outbreaks have been reported in urban areas around the world after heavy rainfall and flood events, which bring the bacteria and their animal hosts in closer contact with humans, including in Guyana, India, Indonesia, Italy, Philippines and Malaysia [12][13][14][15][16][17]. A systematic review of leptospirosis outbreaks identified that out of 318 leptospirosis outbreaks from 1970 to 2012, among the ones that had information about the settings, 16% occurred in urban and 15% in rural areas [18]. Endemic transmission of leptospirosis is reported in rural areas and is frequently associated with specific occupational groups therein, as described in Argentina, Brazil, Nicaragua, Lao, Mexico, New Zealand and Sri Lanka [19][20][21][22][23][24][25][26][27].…”

Molecular and serological characterization of pathogenic Leptospira spp. isolated from symptomatic dogs in a highly endemic area, Brazil

“…Leptospirosis is a bacterial zoonotic disease of worldwide distribution, potentially lethal and capable of causing epidemic outbreaks in human and domestic animal populations [ 1 , 2 ]. Dogs can act as an important source of infection for humans and other mammals, as they are able to excrete the pathogen into the environment via urine and other body fluids [ 3 ].…”

Molecular and Serological Characterization of Pathogenic Leptospira Spp. Isolated From Symptomatic Dogs in a Highly Endemic Area, Brazil

“…Leptospirosis is a bacterial zoonotic disease of worldwide distribution, potentially lethal and capable of causing epidemic outbreaks in human and domestic animal populations (1,2). Dogs can act as an important source of infection for humans and other mammals, as they are able to eliminate the pathogen into the environment via urine and other body uids (3).…”