Stool or blood culture? A search for a gold standard for isolation of salmonella typhi from patients with clinical symptoms of enteric fever in Bauchi state tertiary hospital

Abstract

Introduction: Salmonella typhi (S. typhi) infection is endemic in Nigeria. In recent time, blood culture and stool were the most common diagnostic means of confirming salmonella infection in humans, since it is based on culture for isolation, identification among others. Although, there is lack of reliable and standard method of culture for its isolation. This study aimed to determine the gold standard between blood and stool for the cultural isolation of S. typhi. Methods: The study used laboratory-based cross-sectional study; patients who presented symptoms of enteric fever visiting Abubakar Tafawa Balewa University Teaching Hospital (ATBUTH) during the period of the study were recruited. Informed consent of volunteers and guardians were obtained and in addition confidentially of the results were ensured. A total of 150 patients samples were collected and cultured including adults and children. The bacterial isolated were identified by gram’s reaction and biochemical characteristics. Result: Out of 150 samples examined, 7 (4.1%) tested positive for S. typhi comprising of 5(71.4%) culture from blood and 2(28.6%) culture from stool. The result of this study shows a significant mean difference (t-value = 2.95, p-value = 0.026) between Blood culture and stool culture at 5% level of significance. The culture from blood was found to be more sensitive than the culture from stool. It is therefore recommended gold standard for S. typhi isolation. Conclusion: The study revealed cultures from blood specimen’s yielded highest number of S.typhi isolates when related to culture from stool samples. Therefore, culture from blood sample should be of priority in the isolation of S. typhi for easy identification of the bacteria. Culture from blood sample remains the gold standard method for isolation of S. typhi when it comes to blood or stool sample.