Workplace risk factors associated with extra-pulmonary tuberculosis among healthcare workers in eThekwini health district, KwaZulu-Natal.

Abstract

Background Tuberculosis (TB) can be categorized as pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB) involving other organs besides the lungs. Healthcare workers (HCWs) are at increased risk of tuberculosis exposure. The average burden among healthcare workers is 2% compared to 0.9% in the general population. EPTB constitutes about 16% of all TB cases. This study aimed to examine occupational, environmental, and demographic risk factors associated with EPTB among healthcare workers.

Methods This was a retrospective case referent type study with two control groups (one without tuberculosis and the other with pulmonary tuberculosis) and cases defined as those with EPTB. 282 records of healthcare workers were reviewed from January 2009 to December 2017.The study reviewed available medical records of healthcare workers from various categories and departments, both clinical and non-clinical. in health facilities within eThekwini Health District, Durban, South Africa. Data was analysed using a chi-square test, t- test and multivariet analysis.

Results The mean incidence of TB in 2016 was 908/100 000 and for EPTB, was estimated at 87.2/100 000 HCWs in eThekwini Health District. Cases without respiratory protective equipment (RPE) use were more than three-fold suceptible (aOR 3.5 95%CI 1.0 – 11.4) compared to a PTB control. Working in a clinical department increased the odds for developing EPTB almost three-fold when compared to those with PTB (aOR 2.9 95% CI 0.6 – 13.2) than among those with no TB (aOR 1.4 95%CI 0.1– 13.8). As expected, HCWs diagnosed with HIV were almost two-fold likely to be exposed to EPTB when compared to thosed with PTB (aOR: 1.9 95% CI 0.9 – 4.0), however, when comparing EPTB to no TB, HIV positivity had a wide confidence interval (aOR: 23.4 95% CI 8.1 – 67.7) rendering the results indeterminate.

Conclusion Occupational risk factors for EPTB are similar to that of pulmonary tuberculosis, however, risk estimates may be greater than those for PTB. Human immunodeficiency virus/ acquired immunodeficiency syndrome (HIV/AIDS) infection increases the odds of exposure to EPTB in HCWs.