Investigation of a Suspected Autochthonous Cholera Case in Brazil After an 18-Year Absence of Reported Cases.

Cholera has caused multiple pandemics and remains a significant global public health threat. After 18 years without autochthonous transmission in Brazil, a 60-year-old man with no travel history presented with abdominal discomfort and acute watery diarrhea. Laboratory testing detected Vibrio cholerae O1 Ogawa, prompting classification as a suspected cholera case. However, genomic analysis showed that the strain lacked the toxigenic virulence factor required to cause cholera, leading to its reclassification as a non-cholera case. This investigation highlights the importance of clinical suspicion, advanced laboratory diagnostics, and continuous epidemiological surveillance for accurate case identification and an appropriate public health response.