Workflow may get a little smoother for infection preventionists who also wear an occupational health hat. The CDC is expected to soon issue new tuberculosis testing guidelines for healthcare workers that will end routine annual TB screening in favor of a baseline test on hire and retesting after an occupational exposure, Hospital Infection Control & Prevention has learned.
The revisions come as TB testing and treatment have improved, while the routine risk of healthcare workers acquiring TB at work has steadily declined.
“There is no literature to support that healthcare workers are at occupational risk of contracting TB from their patients anymore,” says co-author of the guidelines, Wendy Thanassi, MD, MA, MRO, a professor at Stanford University and chief of occupational health Services at the VA Palo Alto Health Care System.
Other factors in the decline of TB as an occupational threat are the engineering controls and prevention measures that have become routine in many hospitals.
“Hospitals have done such a good job with environmental controls — negative pressure rooms, air filters, air circulation, and identifying patients and wearing masks early,” she says. “We have seen transmission decline because of these environmental controls.”
The CDC reported 9,093 new cases of TB in the United States in 2017.1 That translates to a rate of 2.8 cases per 100,000 people, a decline of 2% from 2016 that continues a trend of TB reduction.
For example, in 2000, there were 16,308 new cases of TB, a rate of 5.8 per 100,000 people. However, TB is still a threat, and IPs should remain vigilant.
“Active TB has a 10% mortality rate,” Thanassi says. “But it is very rare that we find it incidentally in a healthcare worker without finding it first in a source [patient].”
Some healthcare workers from countries with higher TB prevalence may have been administered the Bacillus Calmette-Guérin (BCG) TB vaccine, which is not routinely administered in the U.S. Those vaccinated may have a cross-reaction to a TB skin test, registering a false positive. The CDC currently recommends use of the TB blood tests for workers who have been immunized with BCG.
The new guidelines are expected to encourage broader use of the TB blood tests over the traditional skin tests, which often are performed in a more labor-intensive two-step approach to ensure accuracy. However, the new guidelines will likely state that those using traditional skin tests can continue to do so, as the CDC typically defers to local preferences rather than a one-size-fits-all approach in its recommendations.
Having used the TB blood tests exclusively for years, Thanassi says the focus should be using the blood tests on hire and treating latent TB at that point rather than conducting routine screening thereafter.
There also are new effective treatments of shorter duration for healthcare workers with latent TB, which can remain dormant for years before activating.
As this report was filed, the CDC had not issued the new guidelines. While Thanassi expected they would be released soon, a CDC spokesman was less definitive.
“We are reviewing the current guidelines and may update them later this year,” says Scott Bryan of the CDC National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention.
As of press time, the current CDC guidelines2 say facilities can use the TB skin test or blood test for healthcare workers at baseline, and then retest thereafter depending on risk categories. Risk factors include the prevalence of TB in the patient population and the community. Hospitals at medium risk are recommended to test healthcare workers annually.
The new CDC guidelines are expected to drop the risk categories, essentially conflating them down to the low-risk recommendation of retesting healthcare workers only if there has been a TB exposure incident, Thanassi says.
- Stewart RJ, Tsang CA, Pratt RH, et al. Tuberculosis — United States, 2017. MMWR 2018;67:317–323.
- CDC. Testing Health Care Workers. Available at: https://bit.ly/2VvLa5J.
