In-hospital contact investigation among health care workers after exposure to pulmonary tuberculosis in an intermediate tuberculosis prevalence area: A prospective study

ABSTRACT

We carried out in-hospital contact investigations of patients with pulmonary tuberculosis and analyzed the prevalence of latent tuberculosis infection (LTBI) among health care workers (HCWs) after TB exposure. A prospective study was conducted of 872 HCWs who were exposed to 55 index cases diagnosed with active pulmonary TB. HCWs after TB exposure were evaluated both TST and chest X-ray at the time of enrollment and 12 weeks after exposure; 625 HCWs (71.6%) underwent both initial assessments; 41 HCWs (6.6%) had a positive TST result. After 12 weeks, 71.1% of HCWs with initial negative TST (n = 415) underwent a second assessment. Ten HCWs had TST conversion. One HCW (0.2%) developed active pulmonary TB. In multivariable analysis, age over 30 years was associated with TST conversion (p = .02). Point prevalence of latent TB was 6.6%, and incidence of LTBI was estimated as 2.4 per 100 HCWs. Strict infection control measures should be emphasized in intermediate TB-burden, BCG-vaccinated countries, especially in HCWs with high risk for TB exposure.

KEYWORDS:

• Health care worker
• infection control
• tuberculin skin test
• tuberculosis

Funding

This study was supported by Research Fund of Seoul St. Mary's Hospital, The Catholic University of Korea. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.