Leptospirosis Risk among Occupational Groups in Brazil, 2010-2015

Leptospirosis is a zoonotic disease that is primarily transmitted through close contact with contaminated environments or infected animals. Brazil has the highest number of reported cases of leptospirosis in the Americas (approximately 4,000 annual cases). The purpose of this study is to identify the occupational groups with a higher risk of leptospirosis in Brazil from 2010 through 2015 among suspected cases reported to the national surveillance system. Confirmed and unconfirmed cases of leptospirosis with laboratory diagnosis, 20,193 and 59,034 respectively, were classified into 12 occupational groups. Confirmed cases were predominantly male (79.4%), between 25 and 59 years of age (68.3%), white (53.4%), illiterate or with incomplete primary education (51.1%), and participating in agricultural work (19.9%). After controlling for age, sex, race, and area of residency, the multivariate analysis identified that between confirmed and unconfirmed cases of leptospirosis reported to the Brazilian national surveillance system, five occupational groups are at higher risk for leptospirosis: garbage and recycling collectors (odds ratio [OR] = 4.10; 95% CI = 3.36-4.99); agricultural, forestry, and fishery workers (OR = 1.65; 95% CI = 1.49-1.84); prisoners (OR = 1.56; 95% CI = 1.04-2.35); building workers (OR = 1.36; 95% CI = 1.22-1.51); cleaners and mining workers (OR = 1.25; 95% CI = 1.07-1.45). This is the first nationwide study to examine leptospirosis risk by occupational group in Brazil using national surveillance data. Our results suggest that among suspected cases there was an increased risk among occupational groups with low income and low educational levels.