Time to Review Your Hospital Tuberculosis Control Plan: Updated CDC Guidance
This is a guest post by Jorge Salinas, MD, Hospital Epidemiologist at University of Iowa Hospitals and Clinics.
The previous guidelines (2005) called for tuberculosis screening for all healthcare workers upon hire and yearly if working in medium-risk settings. The setting risk was calculated based on the number of TB cases seen in the previous year. While most United States Hospitals were considered low risk, many large academic medical centers and hospitals in states with a higher incidence of TB were considered medium-risk. Fortunately, a number of studies performed in developed settings show that the rate of latent TB infection among healthcare workers is not different than the general population. In the updated guidance, hospitals previously considered medium-risk would continue testing upon hire but discontinue yearly TB screening (tuberculin skin testing or interferon gamma-release essay). This recommendation is welcomed as employee health resources can then be allocated to other emerging concerns (e.g., maximizing immunizations among healthcare workers).
The new guidance does not reduce the requirement for fit testing likely because the current TB infection prevention measures (administrative and environmental controls and personal protective equipment use) are likely the reason for such low levels of TB transmission among healthcare workers. As more data is gathered, next research steps could involve studying the necessary frequency of fit testing or the best method used (qualitative or quantitative methods).
These new recommendations will need to be accompanied by adequate contact investigations in healthcare settings. In the past, even if some contacts were not identified, the routine yearly screening would detect those patients within one year of the exposure. Now, an unidentified contact could go unnoticed until TB disease occurs. This increases the importance of training and knowledge of TB contact investigations in healthcare settings. However, TB contact investigations in healthcare settings are not straightforward: healthcare workers may have baseline positive skin testing and it is difficult to quantify the exposure risk (there is no standard recommended threshold for distance from patient or duration of exposure). Even if there was a recommended threshold, it would likely vary depending on other factors such as patient infectiousness (cavities, smear positivity) and healthcare worker immune status. Out of caution, healthcare workers may also tend to overreport exposures potentially overwhelming infection prevention programs. Another unique aspect of TB in healthcare settings involves extrapulmonary TB. Although in public health settings extrapulmonary TB is deemed likely not transmissible, it may lead to exposures in healthcare settings, especially during wound care, or procedures that may generate aerosols or splashes (irrigation, or bone surgery).
Congratulations and thank you to NTCA and CDC for their updated recommendations in light of new evidence. Those on the frontlines (Employee Health and Infection Prevention programs) will be able to reallocate resources and put their TB contact investigations skills to test.