Effectiveness of control measures to prevent transmission of tuberculosis infection to healthcare workers: A systematic review

Article type
Authors
Schmidt B1, Engel ME2, Abdullahi L3, Ehrlich R4
1School of Public Health and Family Medicine, University of Cape Town
2Department of Medicine, University of Cape Town
3Vaccines for Africa, Institute of Infectious Disease and Molecular Medicine & Division of Medical Microbiology, University of Cape Town
4Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town
Abstract
Background: To prevent transmission of tuberculosis (TB) infection in healthcare workers (HCWs), the World Health Organization (WHO) recommends a range of controls. However, assessment of the evidence for their effectiveness is limited, particularly in high TB burden settings.

Objectives: To conduct a systematic review evaluating whether WHO recommended administrative, environmental and personal protective measures are effective in preventing tuberculin skin test conversion among HCWs.

Methods: Using pre-defined inclusion criteria, we searched a number of electronic databases, complemented by hand-searching of reference lists and contacting experts. Reviewers independently selected studies, extracted data and assessed study and overall evidence quality.

Results: Ten before-after studies, including two from high TB burden countries, were included in the review. All reported a decline in tuberculin conversion frequency after the intervention. All were assessed as having ‘unclear’ or high risk of bias on relevant EPOC criteria. The quality of evidence was rated as 'moderate' using GRADE criteria.

Conclusions: This systematic review provides moderate quality of evidence for the effectiveness of a combination of control measures to reduce TB transmission in HCWs in both low and high TB burden settings. However, more studies in low resource, high TB burden settings are needed, with explicit attention to methodological quality. Such studies should also focus on control measures that are appropriate to the resources and capabilities of the health system.