Prevalence and correlates of latent tuberculosis infection in adult population in Nigeria: Monitoring a silent epidemic

Background: Tuberculosis (TB) is a chronic disease caused by Mycobacterium tuberculosis. Latent TB infection (LTBI) is an asymptomatic state. This study aimed to measure the prevalence of latent tuberculosis infection using Interferon Gamma Release Assay (IGRA), among asymptomatic individuals in the general population in Ogun State, Nigeria from the 1st of January, 2022 to the 30th of June, 2023 and correlate the results of the IGRA with their socio-demographic characteristics. Methods: Participants were recruited from the 3 senatorial districts with convenience sampling techniques. An interviewer-administered questionnaire was used to collect data on socio-demographic characteristics, clinical assessment for TB, history of past of chronic lung diseases and TB. Blood sample was taken from each participant for QuantiFERON TB Gold Plus testing. The data was analyzed with SPSS version 22.0. The level of significance was set at P <0.05. Results: A total of 390 individuals participated in this study: 162 (41.5%) males and 228 (58.5%) females. The mean age was 45.63±2.33. The prevalence of latent TBI was 19.7%. Gender (p=0.033), BMI (p=0.036), type of housing unit (p=0.027), and number of rooms persons per room (p=0.001) were the factors associated with a positive IGRA test. However, multiple regression analysis showed that BMI was the only factor that predicts latent TBI (OR = -12.12 + 0.26). Conclusion: Although our results showed a low prevalence of latent TBI in individuals asymptomatic for TB, with statistically significance associations between IGRA results and some socio-demographic characteristics, this depicts a low level of exposure to TB in Ogun State, Nigeria.