Taiwan CDC rules out first local typhoid case due to lab error

The Taiwan Centers for Disease Control (CDC) has officially ruled out the year’s first reported local case of typhoid fever, revealing it was a laboratory misdiagnosis. Following a report in late July regarding a female patient in her 70s from central Taiwan presenting with fever and diarrhea, the CDC conducted whole-genome sequencing on the sample.

The sequencing confirmed the strain was actually non-typhoidal Salmonella rather than Salmonella Typhi. This marks the first time in the country’s history that a confirmed typhoid case has been subsequently overturned after a misdiagnosis.

The error was attributed to human misinterpretation during a serum agglutination test. The CDC noted that weak positive reactions can occur due to cross-reactivity with other bacteria, insufficient operator experience, or improper reagent handling. While no punitive measures are planned, the CDC has mandated that accredited laboratories implement a ‘double-check’ mechanism to verify biochemical characteristics and test data before releasing results. The patient has since recovered and been discharged.