A brucellosis outbreak and risk factors in a dairy farm

ObjectiveTo understand the causes of a brucellosis outbreak and associated risk factors in a dairy farm in 2017.

MethodsAll the workers in the dairy farm were surveyed by using a self-administrated questionnaire in face to face interviews. For each worker, blood sample was collected for tube agglutination test.

ResultsA total of 99 workers were surveyed. Twelve workers were positive in serological tube agglutination test, and the infection rate in milkers was highest (5/20, 25.00%). Nine brucellosis cases were confirmed. The cases were aged between 23 and 55 years, the main clinical symptoms were joint or muscle pain and fatigue without fever; and the antibody titers of 3 latent infection cases were all 1∶100++. Risk factors associated with brucellosis were contact with livestock apoblema（RR＝3.73, 95% CI: 1.07–7.27）, contact with sick cattle（RR＝4.07, 95% CI: 1.07–7.33）, vaccinating livestock（RR＝9.11, 95% CI: 1.37–21.22）, repeated use of gloves（RR＝5.09, 95% CI: 1.16–14.63）.

ConclusionExposure to livestock apoblema, vaccinating livestock and repeated use of gloves might be main risk factors for brucellosis in the workers. It is necessary to strengthen the prevention and control of animal brucellosis epidemic and health education about brucellosis in occupational groups. Close attention should be paid to the supervision of milk production process.