[Outbreak of nephritis by Streptococcus equi subspecies zooepidemicus: case-control study in the municipality of Monte Santo de Minas, Minas Gerais, Brazil, 2013].

Objective: to investigate an outbreak of nephritis by Streptococcus zooepidemicus in Monte Santo de Minas, Minas Gerais State, Brazil.

Methods: a case-control study and attempt to isolate the bacterial agent were carried out from January to April 2013, using clinical and laboratory data, interviews and inspections.

Results: 417 suspected cases were reported, of which 175 (42.0%) were confirmed; 90.9% lived in that municipality, of which 67.4% were female, with median age of 36 years; 24% of cases were hospitalized; three ice cream shops in the municipality used type A milk; there was significant association between the illness and the consumption of type A milk (odds ratio [OR]=4.16/95%CI: 1.55;11.18), one of the ice cream made with this milk (OR=3.09/95%CI: 1.39;6.86) and milk shake of non-processed milk (OR=3.25/95%CI: 1.13;9.36); the bacterium was not detected in rural properties.

Conclusion: the outbreak of nephritis by Streptococcus zooepidemicus was associated with the consumption of milk and dairy products.