Diagnostic utility of a single Widal test in the diagnosis of typhoid fever at Aga Khan University Hospital (AKUH), Nairobi, Kenya.

Typhoid fever is a systemic illness caused by Salmonella enterica serovar typhi (S. typhi) and is endemic in Kenya, where a single Widal test done on an acute phase serum is the most commonly used test. Using a cut-off value of 1:320 for both O and H agglutinins as being diagnostic of S. typhi, only 18 (26%) of our patients had diagnostic titres; 37 (53.6%) had O and H titres less than 1:40. Our study showed that Widal testing done on an acute phase serum of a patient suspected to have typhoid fever had limited diagnostic capability given its low sensitivity.