Phylogenetic lineages of tuberculosis isolates and their association with patient demographics in Tanzania.

BACKGROUND: Mycobacterium tuberculosis presents several lineages each with distinct characteristics of evolutionary status, transmissibility, drug resistance, host interaction, latency, and vaccine efficacy. Whole genome sequencing (WGS) has emerged as a new diagnostic tool to reliably inform the occurrence of phylogenetic lineages of Mycobacterium tuberculosis and examine their relationship with patient demographic characteristics and multidrug-resistance development. METHODS: 191 Mycobacterium tuberculosis isolates obtained from a 2017/2018 Tanzanian drug resistance survey were sequenced on the Illumina Miseq platform at Supranational Tuberculosis Reference Laboratory in Uganda. Obtained fast-q files were imported into tools for resistance profiling and lineage inference (Kvarq v0.12.2, Mykrobe v0.8.1 and TBprofiler v3.0.5). Additionally for phylogenetic tree construction, RaxML-NG v1.0.3(25) was used to generate a maximum likelihood phylogeny with 800 bootstrap replicates. The resulting trees were plotted, annotated and visualized using ggtree v2.0.4 RESULTS: Most [172(90.0%)] of the isolates were from newly treated Pulmonary TB patients. Coinfection with HIV was observed in 33(17.3%) TB patients. Of the 191 isolates, 22(11.5%) were resistant to one or more commonly used first line anti-TB drugs (FLD), 9(4.7%) isolates were MDR-TB while 3(1.6%) were resistant to all the drugs. Of the 24 isolates with any resistance conferring mutations, 13(54.2%) and 10(41.6%) had mutations in genes associated with resistance to INH and RIF respectively. The findings also show four major lineages i.e. Lineage 3[81 (42.4%)], followed by Lineage 4 [74 (38.7%)], the Lineage 1 [23 (12.0%)] and Lineages 2 [13 (6.8%)] circulaing in Tanzania. CONCLUSION: The findings in this study show that Lineage 3 is the most prevalent lineage in Tanzania whereas drug resistant mutations were more frequent among isolates that belonged to Lineage 4.

The second national anti-tuberculosis drug resistance survey in Tanzania, 2017-2018.

OBJECTIVE: To determine the levels and patterns of resistance to first- and second-line anti-tuberculosis (TB) drugs among new and previously treated sputum smear positive pulmonary TB (PTB) patients. METHODS: We conducted a nationally representative cross-sectional facility-based survey in June 2017-July 2018 involving 45 clusters selected based on probability proportional to size. The survey aimed to determine the prevalence of anti-TB drug resistance and associated risk factors among smear positive PTB patients in Tanzania. Sputum samples were examined using smear microscopy, Xpert MTB/RIF, culture and drug susceptibility testing (DST). Logistic regression was used to account for missing data and sampling design effects on the estimates and their standard errors. RESULTS: We enrolled 1557 TB patients, including 1408 (90.4%) newly diagnosed and 149 (9.6%) previously treated patients. The prevalence of multidrug-resistant TB (MDR-TB) was 0.85% [95% confidence interval (CI): 0.4-1.3] among new cases and 4.6% (95% CI: 1.1-8.2) among previously treated cases. The prevalence of Mycobacterium tuberculosis strains resistant to any of the four first-line anti-TB drugs (isoniazid, rifampicin, streptomycin and ethambutol) was 1.7% among new TB patients and 6.5% among those previously treated. Drug resistance to all first-line drugs was similar (0.1%) in new and previously treated patients. None of the isolates displayed poly-resistance or extensively drug-resistant TB (XDR-TB). The only risk factor for MDR-TB was history of previous TB treatment (odds ratio = 5.7, 95% CI: 1.9-17.2). CONCLUSION: The burden of MDR-TB in the country was relatively low with no evidence of XDR-TB. Given the overall small number of MDR-TB cases in this survey, it will be beneficial focusing efforts on intensified case detection including universal DST.

Knowledge of Tuberculosis preventive treatment among people living with HIV: A cross-sectional survey in selected regions of Tanzania.

BACKGROUND: Tuberculosis remains a significant global health concern, especially for People Living with HIV, who are at an increased risk of severe TB disease. Despite the availability of TB Preventive Treatment, knowledge gaps persist among People Living with HIV regarding its importance, accessibility, and administration. The study aimed to assess TPT knowledge levels and determinants among People Living with HIV in Tanzania. METHODS: A cross-sectional survey was conducted from April to May 2023 in 12 regions of mainland Tanzania. The study included PLHIV aged 18 years and above, receiving HIV care in selected Care and Treatment Centers. Data were collected through face-to-face interviews using a semi-structured questionnaire covering sociodemographic characteristics and Tuberculosis preventive treatment knowledge. Descriptive statistics, chi-square tests, and logistic regression analyses were employed for data analysis. RESULTS: Out of the 391 People Living with HIV interviewed, 71.4% demonstrated adequate Tuberculosis preventive treatment knowledge. Female participants, those attending urban health facilities, and individuals with longer durations of HIV care exhibited higher Tuberculosis preventive treatment knowledge levels. However, knowledge disparities persisted based on demographic characteristics such as gender and location of health facilities. CONCLUSION: While a considerable portion of People Living with HIV demonstrated adequate higher Tuberculosis preventive treatment knowledge, addressing gaps among those with lower understanding is crucial. Targeted education campaigns tailored to the needs of People Living with HIV, especially in rural areas and among male populations, are essential. Collaborative efforts between national health programs and community organizations are vital to integrate Tuberculosis preventive treatment awareness effectively into comprehensive HIV care programs, ultimately reducing the burden of Tuberculosis among People Living with HIV and the general population.