Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Jul 15:44:e78.
doi: 10.26633/RPSP.2020.78. eCollection 2020.

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

Claudia Munoz-Zanzi  1 , Emily Groene  1 , Bozena M Morawski  1 , Kimberly Bonner  1 , Federico Costa  2 , Eric Bertherat  3 , Maria Cristina Schneider  4
Affiliations
Review

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

Claudia Munoz-Zanzi et al. Rev Panam Salud Publica. .

Abstract
in English, Spanish

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.

Objetivo: Describir la distribución geográfica y temporal, los métodos de detección y otras características epidemiológicas de los brotes de leptospirosis publicados con el fin de fundamentar los esfuerzos tendientes a estandarizar las prácticas empleadas en la notificación de brotes.

Métodos: Se llevó a cabo una revisión sistemática de los brotes de leptospirosis notificados en la bibliografía científica y en ProMED entre 1970 y 2012. Se utilizaron criterios predefinidos para identificar y clasificar los brotes y se empleó un formulario estándar para extraer la información.

Resultados: Entre 1970 y 2012 se identificaron 318 brotes (promedio: 7 brotes/año; rango: 1-19), la mayoría de ellos en América Latina y el Caribe (36%), región seguida por Asia meridional (13%) y América del Norte (11%). La mayoría de los brotes se localizaron en ecorregiones tropicales y subtropicales (55%). La clasificación cualitativa reveló que en el 40% de los brotes había una clara descripción de los casos confirmados por laboratorio. Entre ellos, el tamaño promedio del brote fue de 82 casos (rango: 2-2259 casos) pero alcanzó los 253 casos en ecorregiones tropicales o subtropicales. Entre los factores de riesgo frecuentes figuraban las actividades laborales al aire libre (25%), la exposición a agua proveniente de inundaciones (23%) y la exposición a agua con fines recreativos (22%). En el 80% de los brotes se realizaron investigaciones epidemiológicas, principalmente entrevistas de casos. La mortalidad específica de los casos fue del 5% (rango: 0%-60%).

Conclusiones: La notificación de brotes aumentó durante el período de estudio, y los brotes abarcaron regiones tropicales y no tropicales. Los brotes fueron diferentes en cuanto a su tamaño, el entorno y los factores de riesgo; sin embargo, los datos examinados con frecuencia incluían una información limitada respecto del diagnóstico y la epidemiología. Se recomiendan directrices para elaborar procedimientos estandarizados para las investigaciones diagnósticas y epidemiológicas durante un brote y para su notificación.

Keywords: Leptospira; Leptospirosis; disease outbreaks; public health surveillance; zoonoses.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest. The authors declare no conflict of interest.

Figures

FIGURE 1.
FIGURE 1.. Flow chart of a systematic literature review of leptospirosis outbreaks reported in scientific literature from 1970 to 2012
FIGURE 2.
FIGURE 2.. Global distribution of human leptospirosis outbreaks reported in the literature by ecoregion obtained from a systematic literature review from 1970 to 2012
FIGURE 3.
FIGURE 3.. Number of human leptospirosis outbreaks by setting obtained from a systematic review of literature between 1970 and 2012 (n = 306)a
See this image and copyright information in PMC

References

    1. Costa F, Hagan JE, Calcagno J, Kane M, Torgerson P, Martinez-Silveira MS. Global morbidity and mortality of leptospirosis: A systematic review. PLoS Negl Trop Dis. 2015;9(9):e0003898. - PMC - PubMed
    2. 1. Costa F, Hagan JE, Calcagno J, Kane M, Torgerson P, Martinez-Silveira MS, et al. Global morbidity and mortality of leptospirosis: A systematic review. PLoS Negl Trop Dis. 2015;9(9):e0003898. - PMC - PubMed
    1. Rood EJJ, Goris MGA, Pijnacker R, Bakker MI, Hartskeerl RA. Environmental risk of leptospirosis infections in the Netherlands: Spatial modelling of environmental risk factors of leptospirosis in the Netherlands. PLoS One. 2017;12(10):e0186987. - PMC - PubMed
    2. 2. Rood EJJ, Goris MGA, Pijnacker R, Bakker MI, Hartskeerl RA. Environmental risk of leptospirosis infections in the Netherlands: Spatial modelling of environmental risk factors of leptospirosis in the Netherlands. PLoS One. 2017;12(10):e0186987. - PMC - PubMed
    1. Sumi A, Telan EF, Chagan-Yasutan H, Piolo MB, Hattori T, Kobayashi N. Effect of temperature, relative humidity and rainfall on dengue fever and leptospirosis infections in Manila, the Philippines. Epidemiol Infect. 2017;145(1):78–86. - PMC - PubMed
    2. 3. Sumi A, Telan EF, Chagan-Yasutan H, Piolo MB, Hattori T, Kobayashi N. Effect of temperature, relative humidity and rainfall on dengue fever and leptospirosis infections in Manila, the Philippines. Epidemiol Infect. 2017;145(1):78–86. - PMC - PubMed
    1. Amilasan AS, Ujiie M, Suzuki M, Salva E, Belo MC, Koizumi N. Outbreak of leptospirosis after flood, the Philippines, 2009. Emerg Infect Dis. 2012;18(1):91–4. - PMC - PubMed
    2. 4. Amilasan AS, Ujiie M, Suzuki M, Salva E, Belo MC, Koizumi N, et al. Outbreak of leptospirosis after flood, the Philippines, 2009. Emerg Infect Dis. 2012;18(1):91–4. - PMC - PubMed
    1. Lau CL, Smythe LD, Craig SB, Weinstein P. Climate change, flooding, urbanisation and leptospirosis: fuelling the fire? Trans R Soc Trop Med Hyg. 2010;104(10):631–8. - PubMed
    2. 5. Lau CL, Smythe LD, Craig SB, Weinstein P. Climate change, flooding, urbanisation and leptospirosis: fuelling the fire? Trans R Soc Trop Med Hyg. 2010;104(10):631–8. - PubMed

LinkOut - more resources