Prevalence of positive TST among Healthcare workers in a high-burden TB setting in Peru

Abstract

Background Tuberculosis (TB) transmission has long been recognized as an important occupational hazard for healthcare workers (HCWs). HCWs possess a 5.8% annual risk of exposure and three times greater risk of developing active TB than the general population.Methods We conducted an observational cross-sectional study between September 2014 and March 2015 among HCWs in a high-burden TB setting in Lima to estimate the prevalence of positive Tuberculin Skin Test (TST) and to investigate factors associated with a positive TST.Results 240 participants were included in the analysis; TST was administered to 190 (79.2%) while the rest were exempted due to a previous positive TST result, history of TB or refused the test. A positive TST result was found among 56.2% of participants (95% CI: 49.22% - 63.55%). When considering those who had a previous positive TST result and those with a history of TB, the prevalence of a positive TST was 64.3% (95% CI: 57.8% - 70.3%). No significant differences of TST results were observed between clinical/paramedical and administrative staff in the health center. The use of N95 mask during work hours was reported by 142 (69.9%) participants. Prevalence ratios (PR) show that workers with more than 120 months as a HCW were 1.44 times more likely to be TST positive. The multivariate analysis found that HCWs with over 10 years of service were 1.62 times more likely to be TST positive.Conclusion This study supports previous reports that TB infection is an occupational hazard for HCWs. Prevention of TB transmission through control measures, as well as timely diagnosis of LTBI in this selected risk group, is critical for the individual and for public health.