Multidrug-resistant tuberculosis surveillance and cascade of care in Madagascar: a five-year (2012–2017) retrospective study

Abstract

Background: In Madagascar, the multidrug-resistant tuberculosis (MDR-TB) surveillance programme was launched in late 2012 wherein previously treated TB cases and symptomatic MDR-TB contacts (hereafter called presumptive MDR-TB cases) undergo drug susceptibility testing. This retrospective review had per aim to provide an update on the national MDR-TB epidemiology, assess and enhance programmatic performance and assess Madagascar's MDR-TB cascade of care. Methods: For 2012-2017, national TB control programme notification, clinical management data and reference laboratory data were gathered. The development and coverage of the surveillance programme, the MDR-TB epidemiology and programmatic performance indicators were assessed using descriptive, logistic and spatial statistical analyses. Data for 2017 was further used to map Madagascar's TB and MDR-TB cascade of care. Results: The geographical coverage and diagnostic and referral capacities of the MDR-TB surveillance programme were gradually expanded whereas regional variations persist with regard to coverage, referral rates and sample referral delays. Overall, the rate of MDR-TB among presumptive MDR-TB cases remained relatively stable, ranging between 3.9% in 2013 and 4.4% in 2017. Most MDR-TB patients were lost in the second gap of the cascade pertaining to MDR-TB cases reaching diagnostic centres but failing to be accurately diagnosed (59.0%). This poor success in diagnosis of MDR-TB is due to both the current use of low-sensitivity smear microscopy as a first-line diagnostic assay for TB and the limited access to any form of drug susceptibility testing. Presumptive MDR-TB patients' sample referral took a mean delay of 28 days before testing. Seventy-five percent of diagnosed MDR-TB patients were appropriately initiated on treatment, and 33% reached long-term recurrence-free survival.

Tuberculosis care cascade in Zambia - identifying the gaps in order to improve outcomes: a population-based analysis

“…This represents the fourth national TB care cascade that has been characterised from a high-burden TB country and builds on similar analyses from South Africa, India and Madagascar. [7][8][9] Our overall TB care cascade results are similar to those from these countries, which each found that only about 50% of all patients with TB were progressing through all steps of the care cascade and completing TB treatment. In India the largest losses in the care cascade were among those who did not access TB testing (28% of all cases).…”

“…In India the largest losses in the care cascade were among those who did not access TB testing (28% of all cases). 7 In Madagascar the largest losses in the cascade were among those who were not diagnosed with TB despite seeking care and accessing a TB diagnostic facility (26% of all cases), 9 while in South Africa steady losses were seen prior to TB diagnosis (12% of all cases), prior to starting TB treatment (13% of all cases) and prior to successful completion of TB therapy (17% of all cases). 8 In Zambia, 40% were estimated to have not accessed TB testing, while 4%–5% of all TB cases were lost at each subsequent step of the care cascade.…”

“…5 6 However, to date, only three high-burden TB countries-South Africa, India and Madagascar-have undertaken and published national-level TB care cascade analyses. [7][8][9] We sought to construct a national TB cascade of care for Zambia to evaluate care delivery for individuals with active TB disease through enumeration of gaps in the overall care cascade in 2018 as well as disaggregated by rifampicin susceptibility results and HIV status. Estimates were derived using multiple data sources, and the overall approach was informed by a recently published methodology for constructing TB care cascades.…”

Epidemiology of tuberculosis and susceptibility to antituberculosis drugs in Reunion Island

“…In these high-risk patients, only 4.5% of patients had MDR tuberculosis and none of them had XDR tuberculosis. However, authors estimated that only two thirds of Malagasy patients were diagnosed and that only 1% of them were tested for genotypic drug resistance [ 21 ]. Our study is one of the few which systematically tested phenotypic and genotypic anti tuberculosis drug resistance in Malagasy people, reporting a very low frequency of resistance (10.3%).…”

Nanopore sequencing for Mycobacterium tuberculosis drug susceptibility testing and outbreak investigation

“…Section S8). 16 In Madagascar, the indirect proportion method on Löwenstein-Jensen medium was performed to test the susceptibility of positive cultures against streptomycin, isoniazid, rifampicin, ethambutol, kanamycin, amikacin and capreomycin. The critical concentrations used were 4, 0.2, 40, 2, 30, 30, and 40 μg/ml, respectively.…”