Detect to Prevent: Evaluating Testing and Treatment Practices for Latent Tuberculosis Infection in Long-Term Care Facilities

Characteristics of TB cases without documented sputum culture in the United States, 2011-2021

BACKGROUND

Culture-based diagnostics are the gold standard for diagnosing pulmonary TB (PTB). We characterized culture practices by comparing cases with documented sputum culture to those without.

METHODS

Using multivariable logistic regression, we examined associations between PTB case characteristics and no documented sputum culture reported to the U.S. National TB Surveillance System during 2011-2021.

RESULTS

Among 69,538 PTB cases analyzed, no sputum culture attempt was documented for 5,869 (8%). Non-sputum culture specimens were documented for 54%, 80%, and 89% of cases without documented sputum culture attempts among persons aged <15 years, 15-64, and 65+ years, respectively; bronchial fluid and lung tissue were common non-sputum specimens among cases in persons >15 years old. Having no documented sputum culture was associated with age <15 years (aOR 23.84, 99% CI 20.09-28.27) or ≥65 years (aOR 1.22, 99% CI 1.07-1.39), culture of a non-sputum specimen (aOR 6.57, 99% CI 5.93-7.28), residence in a long-term care facility (aOR 1.58, 99% CI 1.23-2.01), and receiving TB care outside of a health department (aOR 1.79, 99% CI 1.61-1.98).

CONCLUSIONS

Inability to obtain sputum from children and higher diagnostic suspicion for disease processes that require tissue-based diagnostics could explain these findings..

Review of Evidence for Using Chest X-Rays for Active Tuberculosis Screening in Long-Term Care in Canada

Background: People living in long-term care facilities (LTCF) are at high risk to develop active tuberculosis primarily as a result of reactivation of a latent TB infection, or endemic transmission between residents. Current national guidelines in Canada are to use a posterior-anterior and lateral chest X-ray to screen for TB for those over 65 years old, upon admission to a LTCF.

Objective: To assess the available evidence for cost benefits of universal chest X-ray screening for new LTCF residents.

Methodology: We conducted a search for all articles published until September 2018, in PubMed and WorlCat databases, in English, using a combination of key words: chest X-ray, chest radiography or CXR, long-term care, elderly, screening, and tuberculosis. We also reviewed publicly available guidelines for screening new residents to LTCF from across Canada. We report on a qualitative synthesis of the evidence in the documents retrieved.

Results: The final review yielded four cost-effectiveness studies (2 of 4 conducted in countries with low incidence), one systematic review, one recommendation/editorial, and one cohort study. We found that in a tuberculosis low-incidence country the CXR cost per identified case was $672,298 CAD. Enacting a more targeted screening program, perhaps one that tests only those who previously had TB, or other high-risk medical conditions may enhance the cost-effectiveness.

Recommendations: We suggest reviewing the screening policy for active TB in people entering LTCF, which is based on a CXR. The results indicate that a targeted search for active TB in people with symptoms or other high-risk medical conditions may be more cost-effective.