In a rare occurrence of locally acquired typhoid fever in Canada, health officials in Ottawa recently traced an outbreak back to a chronic Salmonella Typhi carrier working as a food handler. The outbreak involved seven confirmed cases from Oct. 2018 to May 2022 and was linked to the asymptomatic carrier through whole genome sequencing (WGS) and social network analysis.
Typically, cases of typhoid fever in Canada are linked to international travel, making this localized outbreak unusual. The investigation led by Ottawa Public Health underscores the potential for chronic carriers, who may shed bacteria without symptoms and unintentionally transmit the disease over an extended period. All eight outbreak-related isolates matched genetically, confirming the cluster.
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