The increase in occurrence of typhoid fever in Cameroon: overdiagnosis due to misuse of the Widal test?

This study investigates the cause of an apparent increase in occurrence of typhoid fever in Cameroon. The reasons explored include an overdiagnosis of the illness related to poor performance of the Widal test in laboratories and interpretation by prescribers. Questionnaires were used in 1996 to evaluate the use and interpretation of the Widal test, and checklists were used to assess its laboratory performance in 2 of the 10 provinces in Cameroon. The majority of prescribers from 20 health facilities (an average of 76% of the doctors and 61% of the nurses) could detect patients who truly had positive Widal tests and needed treatment. However, an average of 48% of the doctors and 84% of the nurses would treat patients who did not require treatment based on the Widal test result. Patients may therefore be treated unnecessarily. Most (88%) of the visited laboratories performed the Widal rapid slide agglutination test as opposed to the conventional tube agglutination test. About 14% of the laboratories that performed the rapid slide agglutination test had a score above average for each criterion evaluated. Misdiagnosis of typhoid fever leads to unnecessary expenditure and exposure of patients to the side-effects of antibiotics. In addition, misdiagnosis may result in delayed diagnosis and treatment of malaria, and other acute febrile illness.