National cross-sectional cluster survey of tuberculosis prevalence in Timor-Leste: a study protocol.

INTRODUCTION: Timor-Leste has one of the world's highest estimated tuberculosis (TB) incidences, yet the data which informs this estimate is limited and the true burden of TB disease is not known. TB prevalence surveys offer the best means of determining robust estimates of disease burden. This study aims to provide an estimate of the prevalence of bacteriologically confirmed pulmonary TB in Timor-Leste and provide additional insights into diagnostic coverage and health-seeking behaviour of persons with symptoms suggestive of TB. METHODS AND ANALYSIS: A national population-based cross-sectional cluster survey will be conducted in which participants aged 15 years and older will be screened for pulmonary TB using an algorithm consisting of symptom screening and digital X-ray of the chest with computer-aided detection software for X-ray interpretation. Xpert Ultra and liquid culture methods will be used to confirm survey TB cases. Additional data will be collected from persons reporting symptoms suggestive of TB to assess health-seeking behaviour and access to TB diagnosis and care. The survey aims to screen a target sample population of 20 068 people, living within 50 clusters, representing every municipality of Timor-Leste. Bacteriologically confirmed pulmonary TB prevalence will be estimated using WHO-recommended methods. ETHICS AND DISSEMINATION: Research ethics approval has been granted by the human research ethics committee of the Northern Territory, Australia, and the Instituto Nacional da Saúde, Timor-Leste. The results will be published in a peer-reviewed scientific journal and disseminated with relevant stakeholders. TRIAL REGISTRATION NUMBER: ACTRN12623000718640.

Experience on the first national anti-TB drug resistance survey (DRS) in Timor-Leste.

BACKGROUND: A national drug resistance survey (DRS) was implemented for the first time in Timor-Leste (TL) in 2019. The primary objective of the survey was to assess the prevalence of drug resistance among new and previously treated pulmonary TB patients in the country. METHODS: This nation-wide cross-sectional survey was conducted in 2019 targeting all new and previously treated sputum smear-positive pulmonary TB patients. Sputum samples were submitted to the National TB Reference Laboratory for confirmation of TB and to determine resistance to rifampicin by Xpert MTB/RIF. Culture was performed on solid media, and culture isolates of confirmed TB cases were shipped to the WHO Supranational TB Reference Laboratory in Chennai, India for whole genome sequencing (WGS). Survey summary statistics, data cross-tabulations and analysis of potential risk factors of rifampicin-resistant TB (RR-TB) were conducted using R statistical software (version 3.5.2). RESULTS: A total of 953 sputum-smear positive patients were enrolled, of which 917 were confirmed as positive for TB by either Xpert MTB/RIF or culture. An electronic web-based system was used for entry and storage of the data. Rifampicin resistance was detected among 0.6% (95% CI 0.2-1.3) of new cases and 2.7% (95% CI 0.5- 8.2) of previously treated cases. WGS was conducted for validation purposes on 65 randomly selected isolates (29% of RR-TB (2/7) and 7% of RS-TB (63/910) by Xpert MTB/RIF or pDST). The original test results agreed with the WGS validation results for 62/64 isolates (97%). CONCLUSION: The prevalence of RR-TB in Timor-Leste is relatively low compared to the estimated proportions of RR-TB in the WHO South-East Asia Region (2.5% [95% CI 1.9-3.3] among new cases and 14% [95% CI 7.7-21] among previously treated cases). The rapid sputum collection and transportation mechanism implemented in the survey demonstrates its feasibility in low resource settings and should be replicated for routinely transporting TB specimens from microscopy labs to GeneXpert sites. Establishment of in-country capacity for rapid molecular diagnostics for both first- and second-line DST is an immediate need for achieving universal drug susceptibility testing (DST) to guide appropriate patient management.