Risk Factors for Tuberculosis and Effect of Preventive Therapy Among Close Contacts of Persons With Infectious Tuberculosis. (24th May 2019)

• Record Type: Journal Article
• Authors: Reichler, Mary R; Khan, Awal; Sterling, Timothy R; Zhao, Hui; Chen, Bin; Yuan, Yan; Moran, Joyce; McAuley, James; Mangura, Bonita
• Is Part Of: Clinical infectious diseases. Volume 70:Number 8(2020)
• Page Start: 1562
• Page End: 1572
• Publication Date: 2019-05-24
• Subjects: tuberculosis -- risk factors -- contacts -- preventive therapy -- contact investigation; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciz438
• Languages: English
• ISSNs: 1058-4838

Abstract

Abstract: Background: Close contacts of persons with pulmonary tuberculosis (TB) have high rates of TB disease. Methods: We prospectively enrolled TB patients and their close contacts at 9 US/Canadian sites. TB patients and contacts were interviewed to identify index patient, contact, and exposure risk factors for TB. Contacts were evaluated for latent TB infection (LTBI) and TB, and the effectiveness of LTBI treatment for preventing contact TB was examined. Results: Among 4490 close contacts, multivariable risk factors for TB were age ≤5 years, US/Canadian birth, human immunodeficiency virus infection, skin test induration ≥10 mm, shared bedroom with an index patient, exposure to more than 1 index patient, and index patient weight loss ( P < .05 for each). Of 1406 skin test–positive contacts, TB developed in 49 (9.8%) of 446 who did not initiate treatment, 8 (1.8%) of 443 who received partial treatment, and 1 (0.2%) of 517 who completed treatment (1951, 290, and 31 cases/100 000 person-years, respectively; P < .001). TB was diagnosed in 4.2% of US/Canadian-born compared with 2.3% of foreign-born contacts ( P = .002), and TB rates for US/Canadian-born and foreign-born contacts who did not initiate treatment were 3592 and 811 per 100 000 person-years, respectively ( P < .001). Conclusions: Treatment for LTBI was highly effective in preventing TB among close contacts of infectious TB patients. Several index patient, contact, and exposure characteristics associated with increased risk of contact TB were identified. These findings help inform contact investigation, LTBI treatment, and other public health prevention efforts. Abstract : In our prospective, multisite study, we identified several index patient, contact, and exposure characteristics associated with increased risk of contact tuberculosis. Tuberculosis rates were 4-fold higher among US/Canadian-born than foreign-born contacts, and treatment for latent infection was highly effective in preventing TB.