Artisan fresh cheese from raw cow's milk as a possible route of transmission in a toxoplasmosis outbreak, in Brazil

BACKGROUND: The objective of this study was to report an outbreak of human toxoplasmosis occurring in the municipality of Montes Claros de Goias, Goias, Brazil, from December 2015 to August 2016. Seven acute cases in June 2016 triggered the subsequent search. METHODS: A total of 251 individuals were selected through an active search, of which 114 (45.4%) agreed to participate in the research and blood collection. For serological diagnosis were used enzyme-linked immunosorbent assay (ELISA) for IgG and IgM and avidity tests. RESULTS: Of the 114 serum samples evaluated, 12.3% (14/114) showed antibodies against Toxoplasma gondii, with a profile indicative of acute infection. Samples of artisan fresh cheese, public water, vegetables and irrigation water were collected. Toxoplasma gondii DNA fragments were amplified using the polymerase chain reaction from two samples of artisan fresh cheese and a sample of irrigation water from the vegetable garden. A control case study was carried out, and the variable cow's artisan fresh cheese consumption was statistically significant (p = .01). CONCLUSIONS: The results showed that cheese analysed and/or irrigated water of vegetable represented an important route of transmission for the disease. This is the first reported outbreak possibly caused by cow's artisan fresh cheese. It is difficult to prove that these routes were the cause of the outbreak; however, the findings allow us to infer that the individuals involved in the outbreak were in contact with these risk factors.