A cluster of co-occurring cases of leptospirosis and brucellosis in a pastoral community of dairy farmers, India, 2023-2024: an epidemiological investigation.

OBJECTIVE

A cluster of leptospirosis and brucellosis cases in a semi-nomadic, pastoral community was reported in October 2023 from Village A, Uttarakhand State, India. This cluster was investigated to describe the epidemiology and potential exposures.

METHODS

Suspected cases were residents with sudden-onset fever or myalgia occurring from 1 August 2023 to 7 January 2024; confirmed cases were suspected cases with laboratory confirmation. Suspected cases were identified through a house-to-house case search and were interviewed regarding sociodemographic variables, symptoms and exposures. Those who consented were tested. Data were cleaned and analysed in Microsoft Excel.

RESULTS

Fifty suspected cases were identified among a total of 300 residents across 85 households. Among these, 27 agreed to be tested, and 25 were confirmed (13 with leptospirosis, 7 with brucellosis and 5 with both leptospirosis and brucellosis). The cases began in September 2023 following flooding and continued until January 2024, with no deaths. The median age (range) of cases was 30 (17-82) years for leptospirosis, 39 (25-56) years for brucellosis and 39 (22-50) years for coinfection. Altogether, females accounted for 92% (12/13) of leptospirosis cases, 57% (4/7) of brucellosis cases and 80% (4/5) of coinfections. Symptoms included fever, myalgia and arthralgia. All cases reported contact with floodwater and animal abortus.

DISCUSSION: This was a laboratory-confirmed co-occurring cluster of leptospirosis and brucellosis, including five cases of coinfection, following flooding, predominantly affecting female Van Gujjar dairy farmers. Education was provided to the community about the hygienic disposal of animal waste.