Health care workers showed an extremely low risk for occupational tuberculosis infection in a low-incidence setting, according to recently published findings.
Researchers wrote that the findings indicated regular TB testing for health care workers is unnecessary.
“In most countries with a low incidence of TB, [health care workers] routinely undergo screening for latent TB infection with a tuberculin skin test and/or an interferon gamma release assay at the time of starting employment (baseline testing) and at regular intervals and/or after potential exposure thereafter,” Claudia C. Dobler, MD, PhD, of the Evidence-Based Practice Center at the Mayo Clinic, and colleagues wrote. “In [health care workers] with a negative baseline test, it is therefore generally possible to determine whether infection occurred during employment, although it is not always possible to ascertain whether infection was related to exposure at the workplace.”
Dobler and colleagues performed a retrospective cohort study of health care workers at the Mayo Clinic in Rochester, Minnesota, who were tested for TB between Jan. 1, 1998, and May 31, 2014. All of the workers in the study were screened using tuberculin skin testing.
A total of 40,142 health care workers underwent testing, the researchers reported. Of these, only 123 had a conversion during the study period. Of the health care workers who converted, only 7% (n = 9) were suspected to have been exposed to TB at work. None of them developed an active case of TB.
Among those who had a tuberculin skin test conversion, most (66%) tested negative with the QuantiFERON-TB Gold test at the time of conversion, Dobler and colleagues wrote.
“In conclusion, based on the results of our study in a low-incidence setting of TB with a very low risk of nosocomial TB transmission, the [tuberculin skin test] seems to be an appropriate test with only a small proportion of conversions (a majority of which might not indicate true TB infection),” the researchers wrote. “In this setting, testing low-risk [health care workers] at baseline and when TB exposure occurs only, rather than at regular intervals, should be considered.”
Dobler CC, et al. Clin Infect Dis. 2017;doi:10.1093/cid/cix861.
Source: Healio