Active case finding of tuberculosis among patients with diabetes mellitus attending diabetes clinic at Webuye County Hospital

Abstract

Background: Tuberculosis (TB) is the leading cause of death from a single infectious agent above Human Immunodeficiency Virus / Acquired Immunodeficiency Syndrome (HIV/AIDS) and it is one of the top ten causes of death with millions of people getting sick from the disease each year. Diabetes Mellitus (DM) is now one of the most common non-communicable diseases. DM increases the risk of TB by at least two to three fold. In Kenya and Webuye in particular, little is known about the prevalence of TB among the population with DM. This study therefore, tries to provide insights into the prevalence of TB among patients with DM and to outline associated risk factors at Webuye County Hospital (WCH). Objective: To assess the prevalence of tuberculosis among patients with diabetes, the proportion of TB cases among presumptive TB cases and association between the occurrence of TB and socio-demographic factors among adult patients with diabetes at WCH. Methods: This was a hospital-based cross-sectional study in which 975 adult patients attending diabetes out-patient clinic at WCH who were recruited using a consecutive sampling method between January 2021 and August 2021. Peduzzi et al. formula for sample size calculation was used to arrive at the sample size. Patient socio-demographic characteristics and co-morbidities were collected using a pretested structured, interviewer administered questionnaire. TB symptoms screening questionnaire was used to identify presumptive TB patients. Sputum samples were collected from presumptive TB cases and subjected to GeneXpert test for TB confirmation. Data was entered in Statistical Package for Social Sciences (SPSS) version 19 software and analysed using STATA statistical software for data science. Categorical and continuous variables were summarized using proportions, medians and interquartile ranges. Bivariate and multivariate analysis were done to test for association between TB diagnosis and socio-demographic characteristics and comorbidities. A p-value <0.05 was considered statistically significant. Results: Of the 975 patients with DM sampled, 27.1% were male and 72.9% were female. The mean age of the participants was 57.527 (SD=12.34). A total of 83participants reported to have one of 8 symptoms that were suggestive of TB thus the prevalence of presumptive TB was 8.5% (95%CI: 6.8, 10.4). The prevalence of TB among those subjected to GeneXpert was 16.7% (95%CI: 9.2, 26.8), while for the whole study sample, prevalence was 1.3 % (95%CI: 0.7, 2.3). Male gender and smoking were associated, p-values of 0.05, 0.02 respectively, with confirmed TB and patients with DM in WCH. Among the comorbidities, having asthma was associated with having TB among patients with DM (p-value=0.01). Conclusion: The prevalence of TB among presumptive TB patients with DM was 16.7% (13, N=78) and the prevalence of bacteriologically confirmed TB using GeneXpert among patients living with DM in WCH was 1.3% (13, N=975). Male gender, smoking, and having asthma were associated with increased risk of developing TB among patients with DM at WCH Recommendation: Routine active case finding among DM patients should be strengthened to reduce the risk of TB infection among patients with DM. Male patients, those who smoke, and those with asthma should be closely monitored for TB.