Close contacts to infectious patients with tuberculosis had high rates of tuberculosis, with most disease diagnosed before or within 3 months after the index patient' diagnosis. Contact investigations need to be prompt to detect tuberculosis and maximize the opportunity to identify and treat latent infection, to prevent disease.

BACKGROUND: Video directly observed therapy (vDOT) was introduced to increase flexibility and meet patient-specific needs for TB treatment. This study aimed to assess the reach and effectiveness of vDOT for TB treatment under routine conditions in Alameda County, CA, USA, a busy, urban setting, from 2018 to 2020.METHODS: We prospectively evaluated routinely collected data to estimate 1) reach (proportion of patients initiated on vDOT vs. in-person DOT); and 2) effectiveness (proportion of prescribed doses with verified administration by vDOT vs. in-person DOT).RESULTS: Among 163 TB patients, 94 (58%) utilized vDOT during treatment, of whom 54 (57%) received exclusively vDOT. Individuals receiving vDOT were on average younger than those receiving in-person therapy (46 vs. 61 years; P < 0.001). The median time to vDOT initiation was 2.2 weeks (IQR 1.1–10.0); patients were monitored for a median of 27.0 weeks (IQR 24.6–31.9). vDOT led to higher proportions of verified prescribed doses than in-person DOT (68% vs. 54%; P < 0.001). Unobserved self-administration occurred for all patients on weekends based on clinic instructions, but a larger proportion of doses were self-administered during periods of in-person DOT than of vDOT (45% vs. 24%; P < 0.001).CONCLUSION: A TB program successfully maintained vDOT, reaching the majority of patients and achieving greater medication verification than in-person DOT.

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 &lt; .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 &lt; .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 &lt; .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.

High rates of HIV were detected among patients and contacts. Despite structured procedures to offer HIV testing, some patients and most contacts did not accept testing. Strategies are needed to improve testing acceptance rates.