Rifampicin Resistant Tuberculosis in Lesotho: Diagnosis, Treatment Initiation and Outcomes

Abstract

the Lesotho guidelines for the management of drug-resistant tuberculosis (tB) recommend initiation of patients diagnosed with rifampicin resistant (RR)-tB on a standardized drug resistant regimen while awaiting confirmation of rifampicin resistant TB (RR-TB) and complete drug susceptibility test results. Review of diagnostic records between 2014 and 2016 identified 518 patients with RR-TB. Only 314 (60.6%) patients could be linked to treatment records at the Lesotho MDR hospital. The median delay in treatment initiation from the availability of Xpert MTB/RIF assay result was 12 days (IQR 7-19). Only 32% (101) of patients had a documented first-line drug resistant test. MDR-TB was detected in 56.4% of patients while 33.7% of patients had rifampicin mono-resistance. Only 7.4% of patients assessed for second-line resistance had a positive result (resistance to fluoroquinolone). Treatment success was 69.8%, death rate was 28.8%, loss to follow up was 1.0%, and 0.4% failed treatment. Death was associated with positive or unavailable sputum smear at the end of first month of treatment (Fisher exact p < 0.001) and older age (p = 0.007). Urgent attention needs to be given to link patients with RR-tB to care worldwide. the association of death rate with positive sputum smear at the end of the first month of treatment should trigger early individualization of treatment.

Linkage to care and treatment outcomes for patients diagnosed with drug-susceptible tuberculosis using Xpert MTB/RIF assay in Thaba-Tseka district in Lesotho

“…A multi-centre study conducted in South Africa and Uganda reported a linkage to care rate of 55% (12/22) amongst HIV-positive patients diagnosed with active drug-susceptible TB, while a study in Malawi reported a linkage to care rate of 40% (23/58) amongst hospitalized patients diagnosed with TB in Lilongwe ( Chawla et al., 2016 ; Shapiro et al., 2018 ). In Lesotho, a study assessing treatment initiation of patients diagnosed with rifampicin-resistant TB using the GeneXpert assay reported a linkage to care rate of 60.6% (314/528) ( Katende et al., 2020 ).…”

“…A study analysing the Lesotho TB diagnostic network reported a national linkage to care rate of 82%, with 2806 of the 3435 patients diagnosed with TB in 2016 initiated on treatment; the remaining 18% of patients could not be traced ( Albert et al., 2020 ). Another study assessing the impact of GeneXpert implementation on the diagnosis, treatment initiation and treatment outcomes of patients with rifampicin-resistant TB reported a linkage to care rate of 61% amongst patients diagnosed between 2014 and 2016; it is likely that the remaining 39% of patients never initiated drug-resistant treatment ( Katende et al., 2020 ).…”

Evaluation of the use of GeneXpert MTB/RIF in a zone with high burden of tuberculosis in Thailand

“…The increase in treatment initiation is similar to what was observed in a nationwide retrospective cohort study in Johannesburg, South Africa, which was reported in 2011 and 2013, when GeneXpert MTB/RIF was implemented across districts and provinces. The results showed that the proportion of patients in whom appropriate TB resistance treatment was initiated increased from 6% to 19% [ 37 ]. Some studies found that the usage of GeneXpert MTB/RIF among patients at risk of drug-resistant TB was low [ 38 – 41 ].…”

Whole-genome sequencing of Mycobacterium tuberculosis for prediction of drug resistance

“…Drug susceptibility tests were performed by laboratory technologists from the TB laboratory using a fully automated Mycobacterial Growth Indicator Tube (MGIT) 960 liquid culture system (Becton Dickinson, USA). The critical concentrations of anti-TB drugs in these specific assays were as follows: rifampicin, 1.0 μg/ml (MGIT); isoniazid, 0.1 μg/ml (MGIT); ethambutol, 5.0 μg/ml (MGIT); streptomycin, 1.0 μg/ml (MGIT); ofloxacin, 1.5 μg/ ml (MGIT); capreomycin, 2.5 μg/ml (MGIT); and amikacin, 1.0 μg/ml (MGIT) [7]. All experimental methods conformed to standardised clinical laboratory procedures and operating regulations.…”