Evaluation of a simple and rapid dipstick assay for the diagnosis of typhoid fever in Indonesia

To support the clinical diagnosis of typhoid fever in Indonesia, where most hospitals and health centres have no facilities for culture, a rapid dipstick assay for the detection of Salmonella typhi-specific IgM antibodies was evaluated on serum samples from 127 patients clinically suspected of having typhoid fever. In a single blood sample collected on admission to hospital, the sensitivity of the dipstick assay was 69.8% when compared with bone marrow culture and 86.5% when compared with blood culture. The specificity as calculated for the group of patients with suspected typhoid fever but a negative culture result was calculated to be 88.9%. Of 80 patients with febrile illnesses other than typhoid fever, reactivity was observed in only three patients with dengue haemorrhagic fever. The assay uses stabilised components that can be stored outside the refrigerator, does not require special equipment, and may be of use in remote health facilities that have no culture facilities.