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

Abstract

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.

Mycobacterium tuberculosis Genotypes and Drug Susceptibility Test Results from Timor-Leste: A Pilot Study

“…The recovered MTB study isolates were all phenotypically and genotypically susceptible to rifampicin, isoniazid, pyrazinamide, and ethambutol. These findings are consistent with data from the national anti-TB DRS, where low rates of resistance to first-line TB drug and MDR-TB were reported [ 5 , 18 ]. However, the small sample size and convenience sampling mean that resistance rates in Timor-Leste cannot be inferred from this study.…”

“…In 2012, the GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) polymerase chain reaction (PCR) assay was introduced into the country. Since then, access to PCR testing has expanded, with the availability of 11 GeneXpert machines [ 5 ] in 8/13 municipalities, coordinated by the National Tuberculosis Control Program (NTP) and supported by the National TB Reference Laboratory (NTRL) at the National Health Laboratory (NHL).…”

“…The extent of TB drug resistance in Timor-Leste was poorly described prior to 2019. In 2019, a National Anti-Tuberculosis Drug Resistance Survey (DRS) was conducted, showing low rates of resistance to first-line drugs with multidrug-resistant TB (MDR-TB) making up less than 2% of culture-confirmed cases [ 5 ].…”

Prevalence of non-tuberculous mycobacteria among people presumed to have tuberculosis, positive for acid-fast bacilli in Mali

“…The rate of sputum AFB-positive patients and MTBc detected by Xpert in our study was slightly lower than the rate reported in other drug-resistance surveys, ranging from 95.8% −97.7%(14–17).…”

Strategi Intervensi untuk Mengeliminasi Kasus Tuberkulosis

“…Peran investigasi kontak serumah sangat kritikal dalam pengontrolan kasus TB secara global dan dibutuhkan untuk disesuaikan dengan latar belakang negara baik dengan beban TB yang rendah maupun tinggi (Yerramsetti et al, 2022). Program Penanggulangan TB mengubah strategi penemuan pasien TB tidak hanya "secara pasif dengan aktif promotif" tetapi juga melalui penemuan aktif secara intensif dan masif berbasis keluarga dan masyarakat (Lopes et al, 2022).…”