Occupational Tuberculosis Among Laboratory Workers in South Africa: Applying a Surveillance System to Strengthen Prevention and Control

Abstract

Background: Tuberculosis (TB) is recognized as an important health risk for health workers, however, the absence of occupational health surveillance has created knowledge gaps regarding occupational infection rates and contributing factors. This study aimed to determine the rates and contributing factors of active TB cases in laboratory healthcare employees at the National Health Laboratory Service (NHLS) in South Africa, as identified from an occupational surveillance system. Methods: TB cases were reported on the Occupational Health and Safety Information System (OHASIS), which recorded data on occupation type and activities and factors leading to confirmed TB. Data collected from 2012 to 2019 were used to calculate and compare TB risks within NHLS occupational groups. Results: During the study period, there were 92 cases of TB identified in the OHASIS database. General workers, rather than skilled and unskilled laboratory workers and medical staff, had the highest incidence rate (422 per 100,000 person-years). OHASIS data revealed subgroups that seemed to be well protected, while pointing to exposure situations that beckoned policy development, as well as identified subgroups of workers for whom better training is warranted. Conclusions: Functional occupational health surveillance systems can identify subgroups most at risk as well as areas of programme success and areas where increased support is needed, helping to target and monitor policy and procedure modification and training needs.

Reducing the risk of tuberculosis transmission for HCWs in high incidence settings

“…This was primarily associated with a low proportion, around 40%, of experienced and trained HCWs in these facilities [25]. Garnett et al [26] reported that laboratory workers were also at high risk of acquiring TB infection. Despite the least contact with patients, laboratory staff had a persistent exposure to TB specimens.…”

“…Garnett et al [ 26 ] reported that laboratory workers were also at high risk of acquiring TB infection. Despite the least contact with patients, laboratory staff had a persistent exposure to TB specimens.…”

“…Despite the least contact with patients, laboratory staff had a persistent exposure to TB specimens. National Health Laboratory Service (NHLS) in South Africa collected data between 2012 and 2019 to evaluate the risk of TB within different occupational groups [ 26 ]. Laboratory workers had a higher incidence rate (160 per 100,000 person-years) compared to medical staff (133 per 100,000 person-years).…”

“…The lack of training, knowledge and awareness of TB transmission was identified as the main factors for high disease incidence in this group. This was also linked to inappropriate sample handling and good laboratory practice not being followed [ 26 ]. These findings suggest that clinical and non-clinical HCWs may have different levels of education and TB IPC training, which consequently contribute to their ability to recognise and respond to potential Mtb exposure.…”

Current Guidelines for Protecting Health Workers from Occupational Tuberculosis Are Necessary, but Not Sufficient: Towards a Comprehensive Occupational Health Approach

“…This suggests that a useful starting point for collaboration between occupational health and IPC is an information system able to track and investigate active TB in health workers for the purposes of risk assessment and targeted IPC. An example is the Occupational Health and Safety Information System (OHASIS), developed through a collaboration of occupational health and IPC professionals at the University of British Columbia with the National Institute for Occupational Health in South Africa, and applied in the National Health Laboratory Service of South Africa [54,55].…”