Comparison of Selected Rapid Diagnostic Kits and Stool Culture in Cholera Diagnosis among Patients Presenting with Diarrhoea Symptoms Attending Nairobi Womens Hospital (Adams)

Abstract

Cholera is an acute watery diarrhoea disease caused mainly by Vibrio Cholerae O1 and less commonly by Vibrio Cholerae O139. Cholera can lead to severe disease and death if untreated. It is transmitted through faecal oral contamination and is thus predominantly associated with lack of safe drinking water, improper sanitation and personal hygiene. Cholera is an important public health concern in many parts of America, Asia and Africa. Globally 3-5 million cases and over 100,000 deaths occur annually due to cholera. This study evaluated the performance of three selected rapid diagnostic kits against stool culture as a gold standard in cholera diagnosis among patients, presenting with diarrhoea symptoms attending The Nairobi Womens Hospital (Adams). In order to achieve these objectives, the study adopted a descriptive cross-sectional method which provided data on the participant’s demographic characteristics and distribution. Performance of the selected rapid diagnostic kits results was compared against stool culture which was used as the reference standard. Kits were Boson, Bioline and Star Diagnostics. Same samples were inoculated in Triple Sugar Iron media for culture analysis. The sample size determination was calculated using Mittal formula (2015) formula with a confidence interval of 95% and a margin error of 5% which gave 293 participants. Data obtained was presented using tables and graphs. Statistical tools applied for data analysis included frequencies, percentages, Pearson Chi-square, ROC curve and Kappa tests. Project approval was obtained and principles of ethics observed throughout the study. The kits used in the study i.e. Boson, Bioline and Star Diagnostics had sensitivity of 87.1% 82.5% and 76.6% respectively. In addition, they achieved a specificity of 96.6%, 95.5% and 93.8 % respectively. The three achieved a substantial level of agreement on Kappa Test (> 0.60).Achieving the recommended cut-off values of 75% sensitivity and 93.6% specificity. Boson was the most sensitive kit as compared to Star Diagnostic kit which was least sensitive. In terms of specificity, Boson also performed better than the three while Star Diagnostic was the least specific. This qualifies the selected Rapid Diagnostic Kits used in this study Ideal for testing. In this regard therefore, since the selected Rapid Diagnostic Tests for Vibrio Cholera are available in the market should be validated and recommended for screening as well as diagnostic purposes.