Therapeutic strategies and outcomes of MDR and pre-XDR-TB in Italy: a nationwide study

A Profile of Drug-Resistant Mutations in Mycobacterium tuberculosis Isolates from Guangdong Province, China

Guangdong Province, China's largest economy, has a high incidence of tuberculosis (TB). At present, there are few reports on the distribution, transmission and drug resistance of Mycobacterium tuberculosis (Mtb) strains in this region. In this study, we performed minimum inhibitory concentration testing for 14 anti-TB drugs and whole-genome sequencing of 713 clinical Mtb isolates from 20,662 sputum culture-positive tuberculosis patients registered at 31 tuberculosis drug resistance surveillance sites covering 20 cities in Guangdong Province from 2016 to 2018. Moreover, we evaluated genome-wide associations between mutations and drug resistance, and further investigated the differences in the MICs of mutations. The epidemiology, drug-resistant phenotypes and whole genome sequencing data of 713 clinical Mtb isolates were analyzed, revealing the lineage distribution and drug-resistant gene profiles in Guangdong Province. WGS combined with quantitative MIC measurements identified several novel loci associated with resistance, of which 16 loci were found to be related to resistance to more than one drug. This study analyzed the lineage distribution, prevalence characteristics and resistance-corresponding gene profiles of Mtb isolates in Guangdong province, and provided a theoretical basis for the formulation of tuberculosis prevention and control policy in the province.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-024-01236-3.

Tuberculosis in migrants: epidemiology, resistance and outcome in Milan, Italy

BACKGROUND

Human migration and the ever-changing geopolitical scenarios are redefining the epidemiology and the management of tuberculosis (TB), especially in low-TB burden countries welcoming high rates of people from high-TB burden countries.

METHODS

We conducted an observational retrospective mono-centric study in a Northern-Italy TB reference centre from 1 January 1990 to 31 December 2019, focusing on the differences in epidemiology, resistance patterns and treatment outcomes between Italians and migrants with active TB. Data were collected from medical records.

RESULTS

A total of 10555 patients were included, 4614 Italians and 5941 migrants. Among migrants, higher rates of rifampin-resistant (RR) or multidrug-resistant (MDR) TB were reported, as well as higher rates of loss to follow-up. Among Italians, higher mortality rates and a higher number of extrapulmonary TB cases were found.

CONCLUSION

Our study describes one of the largest cohorts of patients with active TB in Italy, highlighting the need for tailored approaches in native and migrant populations.

Long-term treatment outcomes in patients with multidrug-resistant tuberculosis

OBJECTIVES

To describe long-term treatment outcomes in patients with multi-drug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB) and validate established outcome definitions for MDR/RR-TB treatment.

METHODS

Among patients with MDR/RR-TB admitted to a German MDR/RR-TB referral centre from 1 September 2002 to 29 February 2020, we compared long-term treatment outcomes derived from individual patient follow-up with treatment outcomes defined by WHO-2013, WHO-2021 and the Tuberculosis Network European Trials Group-2016.

RESULTS

In a total of 163 patients (mean age, 35 years; standard deviation, 13 years; 14/163 [8.6%] living with HIV; 109/163 [66.9%] men, 149/163 [91.4%] migrating to Germany within 5 years), the treatment of culture-confirmed MDR/RR-TB was initiated. Additional drug resistance to a fluoroquinolone or a second-line injectable agent was present in 15 of the 163 (9.2%) Mycobacterium tuberculosis strains; resistance against both the drug classes was present in 29 of the 163 (17.8%) strains. The median duration of MDR/RR-TB treatment was 20 months (interquartile range, 19.3-21.6 months), with a medium of five active drugs included. The median follow-up time was 4 years (47.7 months; interquartile range, 21.7-65.8 months). Among the 163 patients, cure was achieved in 25 (15.3%), 82 (50.3%) and 95 (58.3%) patients according to the outcome definitions of WHO-2013, WHO-2021, and the Tuberculosis Network European Trials Group-2016, respectively. The lost to follow-up rate was 17 of 163 (10.4%). Death was more likely in patients living with HIV (hazard ratio, 4.28; 95% confidence interval, 1.26-12.86) and older patients (hazard ratio, 1.08; 95% confidence interval, 1.05-1.12; increment of 1 year). Overall, 101/163 (62.0%) patients experienced long-term, relapse-free cure; of those, 101/122 (82.8%) patients with a known status (not lost to-follow-up or transferred out) at follow-up.

CONCLUSION

Under optimal management conditions leveraging individualized treatment regimens, long-term, relapse-free cure from MDR/RR-TB is substantially higher than cure rates defined by current treatment outcome definitions.

Diagnosis and Treatment Pathway of MDR/RR-TB in Taizhou, Zhejiang Province, China

This study aims to understand MDR/RR-TB patients' experience from seeking TB-related health care to diagnosis and treatment completion, as well as the social determinants with the waiting time for DST and treatment, pre-treatment attrition, and treatment outcome based on a retrospective cohort study. Univariate and multi-variate logistic regressions were used to analyze the associated factors. The median time of waiting time for DST and treatment was 24.00 and 30.00 days, respectively. Non-residential patients (aOR: 2.89, 95% CI: 1.14-7.70), registered before 2018 (aOR: 19.93, 95% CI: 8.99-48.51), first visited a county-level hospital (aOR: 4.65, 95% CI: 1.08-21.67), sputum smear-negative (aOR: 3.54, 95% CI: 1.28-10.16), and comorbid with pneumoconiosis (aOR: 7.10, 95% CI: 1.23-47.98) had a longer DST delay. The pre-treatment attrition was 26.9% (82/305). Elderly, non-residential patients and patients registered before 2018 were more likely to refuse MDR/RR treatment. However, in housekeeping/unemployment and farmer/fisherman, recurrent patients tended to take therapeutic measures actively. The successful treatment rate was 62.1% (105/169). Elderly, comorbidity with diabetes and sputum smear conversion time >1 month may lead to poorer outcomes. Immediate interventions should be taken to smooth diagnosis and treatment pathways and improve the social protections further so as to encourage patients to cooperate with the treatment actively.

Revised Definitions of Tuberculosis Resistance and Treatment Outcomes, France, 2006-2019

Definitions of resistance in multidrug-resistant tuberculosis (MDR TB) and extensively drug-resistant tuberculosis (XDR TB) have been updated. Pre-XDR TB, defined as MDR TB with additional resistance to fluoroquinolones, and XDR TB, with additional resistance to bedaquiline or linezolid, are frequently associated with treatment failure and toxicity. We retrospectively determined the effects of pre-XDR/XDR TB resistance on outcomes and safety of MDR TB treatment in France. The study included 298 patients treated for MDR TB at 3 reference centers during 2006-2019. Of those, 205 (68.8%) cases were fluoroquinolone-susceptible MDR TB and 93 (31.2%) were pre-XDR/XDR TB. Compared with fluoroquinolone-susceptible MDR TB, pre-XDR/XDR TB was associated with more cavitary lung lesions and bilateral disease and required longer treatment. Overall, 202 patients (67.8%) had favorable treatment outcomes, with no significant difference between pre-XDR/XDR TB (67.7%) and fluoroquinolone-susceptible MDR TB (67.8%; p = 0.99). Pre-XDR/XDR TB was not associated with higher risk for serious adverse events.