Performance of Widal test and stool culture in the diagnosis of typhoid fever among suspected patients in Dar es Salaam, Tanzania

Abstract

Objective We set an experiment to determine the diagnostic performance of the Widal test and stool culture in typhoid-suspected cases attending tertiary hospitals in Dar es Salaam, Tanzania using blood culture as a golden standard. We also evaluated the agreement between Widal, stool and blood culture. Results This was a cross-sectional study conducted between June and September 2018, in three Regional Referral Hospitals in Dar es Salaam, Tanzania. A total of 158 typhoid-suspected cases were enrolled, after obtaining an informed consent. Of the 158 patients participated in the study, 128 (81%) tested positive for the Widal test and 17 (11%) patients were stool culture positive. Widal test recorded 81.5% sensitivity, 18.3% specificity, 10.1% positive predictive value and 89.7% negative predictive value. Stool culture showed 31.3% sensitivity, 91.5% specificity, 29% positive predictive value and 91.5% negative predictive value. In conclusion, Widal test is not reliable for diagnosis of typhoid fever since false positive and negative results are common. In addition, Widal test recorded poor agreement with the blood culture (kappa = 0.014, p < 0.05) while stool culture had strong agreement with the blood culture (kappa = 0.22, p < 0.05).

Clinical presentations, diagnostics, treatments and treatment costs of children and adults with febrile illness in a tertiary referral hospital in south-eastern Guinea: a retrospective longitudinal cohort study.

“…Widal TO/TH agglutination test is widely used and plays a major role in ascertaining this diagnosis. While this low-cost point-of-care test may be indicative of enteric fever in certain clinical situations and may be used according to Guinean national guidelines, its use is often discouraged due to its low speci city [43,44]. In our study, 18.2% of all inpatients had a positive Widal TO/TH test result and a considerable proportion of patients was treated with antimicrobial drugs commonly used for gastroenteritis, namely ampicillin, metronidazole and ceftriaxone.…”

The Optimum Cut-off Value of the Nelwan Score to Diagnose Typhoid Fever in Adults

“…20,21,22 False negative in PCR may result from small numbers of bacteria, gene mutation, and inhibitory substances in the sample. 21,22,23,24…”

Epidemiological investigation of a typhoid fever outbreak in Sekhukhune District, Limpopo province, South Africa – 2017

“…16 The use of Widal test may result in misdiagnosis and mismanagement of patients. 9,10,27 During the investigation period, in-service training on clinical management and public health response of typhoid fever were conducted in the district after it became known that there was no uniformity in patient management amongst clinicians. Typhoid fever management guidelines were distributed to all hospitals to ensure the proper management of patients.…”

“…However, the Widal test is not a recommended confirmatory test because of its low sensitivity, specificity and positive predictive value. 9,10 The World Health Organization (WHO) estimates that approximately 21 million cases and 222 000 typhoid-related deaths occur annually worldwide. 11 South Africa has observed mixed patterns of endemic disease and sporadic cases in more industrialised areas of the country through active laboratory-based surveillance, conducted by GERMS-SA of the National Institute for Communicable Diseases (NICD).…”