Accuracy of negative tuberculin skin test in predicting in-hospital TB mortality
SAN DIEGO, October 06, 2017 — Malnutrition, increasing age, and negative tuberculin skin test (TST) results are factors that may weaken the immune system and subsequently increase in-hospital mortality in hospitalized people with tuberculosis (TB), according to results from a retrospective study presented at IDWeek 2017.
Investigators retrospectively evaluated 961 hospitalized people with TB and assessed in-hospital mortality rates among those who received either a negative or positive TST result. A negative TST result was defined as less than 10 mm in duration. Researchers also evaluated associations among clinical and sociodemographic factors, TST, and in-hospital mortality.
According to the findings, 19.2% of patients had negative TST results. In addition, 2.9% of analyzed patients experienced in-hospital mortality. Characteristics of the patients who died with a negative TST result included a positive acid-fast bacilli smear (48.7%), foreign birth (47.9%), malnutrition (22.7%), homelessness (18.0%), TB history (16.7%), positive HIV diagnosis (2.5%), and multidrug-resistant TB (1.7%).
In total, only negative TST results, malnutrition, and age demonstrated a significant correlation with in-hospital mortality (all P <.005). Compared with patients with a positive TST, participants who had a negative TST result had a 2.2-fold higher risk for in-hospital death (95% CI, 1.1-4.2).
According to Dr Joo and colleagues, the findings reflect a possible "weakened cellular immune reaction to Mycobacterium tuberculosis antigens," and the use of TST results may possess utility as a prognostic tool for identifying patients with a higher risk for mortality in the hospital setting.
Reference
Joo SJ, Kim J, Cegielski P. Risk factors associated with in-hospital mortality among patients with active TB disease: 25-year experience in the US. Presented at: IDWeek 2017; October 4-8, 2017; San Diego, CA. Poster 2424.
Source: Infectious Disease Advisor
