Risk for Prison-to-Community Tuberculosis Transmission, Thailand, 2017-2020.

To determine contributions of previously incarcerated persons to tuberculosis (TB) transmission in the community, we performed a healthcare facility-based cohort study of TB patients in Thailand during 2017-2020. We used whole-genome sequencing of Mycobacterium tuberculosis isolates from patients to identify genotypic clusters and assess the association between previous incarceration and TB transmission in the community. We identified 4 large genotype clusters (>10 TB patients/cluster); 28% (14/50) of the patients in those clusters were formerly incarcerated. Formerly incarcerated TB patients were more likely than nonincarcerated patients to be included in large clusters. TB patients within the large genotype clusters were geographically dispersed throughout Chiang Rai Province. Community TB transmission in the community was associated with the presence of formerly incarcerated individuals in Thailand. To reduce the risk for prison-to-community transmission, we recommend TB screening at the time of entry and exit from prisons and follow-up screening in the community.

Integrating services for HIV and multidrug-resistant tuberculosis: A global cross-sectional survey among ART clinics in low- and middle-income countries.

Tuberculosis (TB) is the leading cause of death among PLHIV and multidrug-resistant-TB (MDR-TB) is associated with high mortality. We examined the management for adult PLHIV coinfected with MDR-TB at ART clinics in lower income countries. Between 2019 and 2020, we conducted a cross-sectional survey at 29 ART clinics in high TB burden countries within the global IeDEA network. We used structured questionnaires to collect clinic-level data on the TB and HIV services and the availability of diagnostic tools and treatment for MDR-TB. Of 29 ART clinics, 25 (86%) were in urban areas and 19 (66%) were tertiary care clinics. Integrated HIV-TB services were reported at 25 (86%) ART clinics for pan-susceptible TB, and 14 (48%) clinics reported full MDR-TB services on-site, i.e. drug susceptibility testing [DST] and MDR-TB treatment. Some form of DST was available on-site at 22 (76%) clinics, while the remainder referred testing off-site. On-site DST for second-line drugs was available at 9 (31%) clinics. MDR-TB treatment was delivered on-site at 15 (52%) clinics, with 10 individualizing treatment based on DST results and five using standardized regimens alone. Bedaquiline was routinely available at 5 (17%) clinics and delamanid at 3 (10%) clinics. Although most ART clinics reported having integrated HIV and TB services, few had fully integrated MDR-TB services. There is a continued need for increased access to diagnostic and treatment options for MDR-TB patients and better integration of MDR-TB services into the HIV care continuum.

Risk factors associated with large clusters of tuberculosis patients determined by whole-genome sequencing in a high-tuberculosis-burden country.

Whole-genome sequencing (WGS) analysis has great discriminative power for detecting similar molecular fingerprints of suspected tuberculosis (TB) clusters. The proportion of TB cases within clusters and the associated risk factors are important epidemiological parameters guiding appropriate outbreak control strategies in endemic settings. We conducted a hospital-based TB case-cohort study between 2003 and 2011 in the northernmost province of Thailand. We identified TB clusters by Mycobacterium tuberculosis WGS and analysed the risks of TB clustering and the characteristics of large clusters compared with small clusters. Among 1146 TB isolates, we identified 77 clusters with 251 isolates defined by a 5-single-nucleotide variant (SNV) cutoff and 112 clusters with 431 isolates defined by a 12-SNV cutoff. Twelve large clusters with 6 isolates or more in each cluster were identified by a 12-SNV cutoff. Sublineage 2.2.1 (both Ancestral and Modern) strains and imprisonment were independently associated with large clusters. Furthermore, although large clusters of Lineage 2.2.1/Ancestral strains included a high number of prisoners, Lineage 2.2.1/Modern strain clusters were only associated with treatment failures and drug resistance. Heterogeneity among lineage strains was observed with respect to large-cluster characteristics. Patients with an increased TB-transmission tendency should be priority targets for contact investigations and outbreak interventions to prevent ongoing transmission.

Contact tracing for tuberculosis, Thailand.

PROBLEM: Despite implementation of universal health coverage in Thailand, gaps remain in the system for screening contacts of tuberculosis patients. APPROACH: We designed broader criteria for contact investigation and new screening practices and assessed the approach in a programme-based operational research study in 2017-2018. Clinic staff interviewed 100 index patients and asked them to give household and non-household contacts an invitation for a free screening and chest X-ray. Contact persons who attended received 250 Thai baht (about 8 United States dollars) allowance for transport. LOCAL SETTING: Chiang Rai province, Thailand, has high rates of tuberculosis notification and a high number of people living in poverty. The coverage of contact investigation in under 5-year-olds was only 33.2% (222 screened out of 668 contacts) over 2011-2015. RELEVANT CHANGES: Index patients identified 440 contacts in total and gave invitation cards to 227 of them. The contact investigation coverage was 81.1% (184/227) and tuberculosis detection among contacts screened was 6.0% (11/184). Of the 11 contacts with active tuberculosis, three did not have tuberculosis symptoms, three were non-household contacts and three were contacts of non-smear-positive tuberculosis patients. The contact investigation coverage of the contacts younger than 5 years was 100% (14/14) and the yield of tuberculosis detection in this age group was 21.4% (3/14). LESSONS LEARNT: High coverage of contact investigation with a high yield of tuberculosis detection among contacts can be achieved by applying broader criteria for contact investigation and providing financial support for transportation.