Healthcare workers should be tested for tuberculosis (TB) when they are hired and should be retested only after an occupational exposure, according to new guidelines issued by the Centers for Disease Control and Prevention (CDC).
The recommendations are a departure from the previous CDC guidelines, published in 2005, for preventing Mycobacterium tuberculosis transmission in healthcare settings, which recommended that all healthcare workers undergo routine annual TB screening.
The revision comes at a time when testing and treatment for TB have improved and the risk for exposure in healthcare settings has declined, Lynn E. Sosa, MD, of the Connecticut Department of Public Health and the National Tuberculosis Controllers Association (NTCA), in Smyrna, Georgia, and colleagues report in an article published online today in Morbidity and Mortality Weekly Report.
To update the guidelines, an NTCA-CDC work group conducted a systematic review of literature published from January 2006 through November 2017 that reported prevalence rates of latent TB infection (LTBI), rates of conversion or reversion of TB test results, or TB transmission rates among healthcare workers in high-income countries in which the incidence of TB was low.
The collective data show that approximately 3% of US healthcare workers test positive for M tuberculosis at baseline when tested with the tuberculin skin test (TST); 5% test positive when tested with interferon-gamma release assay (IGRA). Additionally, in less than 1% of this population do negative baseline TST results convert to positive on serial testing. With IGRA, the conversion rate is 4%. With TST, approximately 62% of those who test positive at baseline subsequently test negative on serial testing. With IGRA, the reversion rate is 48%.
Moreover, no healthcare workers in the studies developed active TB. The evidence was insufficient to assess the incidence and transmission of TB on the basis of occupational and nonoccupational risk.
The updated recommendations reflect these findings. As in the 2005 guideline, the new guideline recommends on-hire TB testing of all healthcare personnel by either IGRA or TST, but it also recommends an individual TB risk assessment and symptom evaluation at baseline.
The recommendations regarding serial screening and testing differentiate between individuals who might have occupational or nonoccupational risks for TB exposure. For example, although routine serial testing of all healthcare workers is no longer recommended, healthcare facilities can consider using it for specific groups of workers who might be at increased occupational risk for TB exposure, such as pulmonologists, respiratory therapists, or individuals working in healthcare settings in which transmissions have previously occurred, such as emergency departments, the authors write. In deciding whether to conduct such testing, consideration should be given to regional infection/prevalence rates and other individualized factors.
When healthcare workers are at increased risk for nonoccupational TB exposure, healthcare facilities should consider conducting periodic risk assessments, as well as testing when new risks are identified. "If these risks are unrecognized, these healthcare personnel might experience TB disease and transmit TB to patients, coworkers, or other contacts," the authors write. "Therefore, healthcare facilities should educate all healthcare personnel annually about TB, including risk factors, signs, and symptoms; facilities also should encourage healthcare personnel to discuss any potential occupational or nonoccupational TB exposure with their primary care provider and occupational health clinician," the authors state.
The revised guideline provides recommendations for follow-up when test results are positive. It strongly recommends that workers whose TB test results are positive undergo chest imaging, symptom assessment, and further evaluation for TB as needed.
In addition, "[h]ealthcare personnel with LTBI and no prior treatment should be offered, and strongly encouraged to complete, treatment with a recommended regimen, including short-course treatments, unless a contraindication exists," the authors write. They note that increasing treatment of LTBI in this population might further decrease the transmission of TB in healthcare settings. "These healthcare personnel also should be educated about the signs and symptoms of TB disease that should prompt an immediate evaluation between screenings," they state.
The guideline authors urge healthcare facilities to work with public health agencies to identify LTBI among healthcare workers. "Public health agencies can serve as a source for technical assistance, medical consultation regarding diagnosis and treatment of LTBI, and clarification of state or local regulations, surveillance requirements, and guidelines," they write. "Sharing information and experiences with public health agencies is necessary for understanding the impact of these recommendations on the overall incidence of TB and LTBI in the United States and the need to revise future recommendations for health care personnel."
Sosa has disclosed no relevant financial relationships. Other authors' financial relationships are listed in the original article.
Morb Mortal Wkly Rep. Published online May 17, 2019. Full text