Daily Respiratory Research Analysis
Three high-impact studies advance respiratory health: a Bangladeshi prospective cohort links betel quid use to higher respiratory and COPD mortality independent of smoking; a national Moldovan analysis shows alarming baseline and acquired resistance to fluoroquinolones, bedaquiline, and linezolid driving MDR/RR-TB treatment failure; and a population-based Catalan cohort demonstrates sustained protection of nirsevimab against severe RSV outcomes across two seasons without rebound severity.
Summary
Three high-impact studies advance respiratory health: a Bangladeshi prospective cohort links betel quid use to higher respiratory and COPD mortality independent of smoking; a national Moldovan analysis shows alarming baseline and acquired resistance to fluoroquinolones, bedaquiline, and linezolid driving MDR/RR-TB treatment failure; and a population-based Catalan cohort demonstrates sustained protection of nirsevimab against severe RSV outcomes across two seasons without rebound severity.
Research Themes
- Behavioral risk factors and respiratory mortality
- Antimicrobial resistance in tuberculosis and treatment failure
- Respiratory virus immunoprophylaxis effectiveness in real-world settings
Selected Articles
1. Association Between Betel Quid Consumption and Respiratory Disease Mortality in a Prospective Bangladeshi Cohort.
In a 20,033-participant prospective cohort in Bangladesh, betel quid use was associated with higher respiratory disease mortality, especially COPD, with a clear dose-response and effects persisting in women and never-smokers. The population attributable fraction for COPD deaths due to betel use was 16.3%, underscoring substantial public health implications.
Impact: This study identifies a prevalent, modifiable exposure linked to excess COPD and respiratory mortality independent of smoking, providing strong evidence to inform prevention policies in South and Southeast Asia and beyond.
Clinical Implications: Clinicians should screen for betel quid use, counsel cessation, and incorporate it into COPD risk assessment, especially for women and never-smokers. Public health programs should target betel cessation alongside tobacco control.
Key Findings
- Ever betel quid use increased respiratory disease mortality (HR 1.38; 95% CI 1.13–1.69).
- COPD mortality was higher among betel users (HR 1.56; 95% CI 1.19–2.05) with dose-response: low vs high consumption HRs 1.46 and 2.47.
- Associations persisted in women (HR 3.63) and never-smokers (HR 3.44); population attributable fraction for COPD deaths due to betel use was 16.3%.
Methodological Strengths
- Large, long-term prospective cohort with standardized data collection and multivariable Cox modeling.
- Robust dose-response analyses and subgroup evaluations (women, never-smokers).
Limitations
- Self-reported betel use may introduce misclassification; intensity metrics may be imperfect.
- Residual confounding and limited generalizability beyond the study region are possible.
Future Directions: Evaluate biological mechanisms linking betel constituents to COPD pathogenesis; implement and trial cessation interventions; expand to multi-country cohorts to assess generalizability.
2. High rates of acquired resistance to fluoroquinolones, bedaquiline, and linezolid in patients failing treatment against drug-resistant tuberculosis in the Republic of Moldova.
National surveillance data from Moldova show that treatment failure in MDR/RR-TB is strongly driven by high baseline and acquired resistance to fluoroquinolones, bedaquiline, and linezolid. Acquired resistance occurred in 39.6% of failures (notably bedaquiline 30.9%), with baseline FQ resistance (OR 4.7) and any acquired Group A resistance (OR 63.5) associated with failure.
Impact: Highlights rapidly emerging resistance to cornerstone second-line anti-TB agents in a high-burden setting, with direct implications for regimen design, surveillance, and stewardship to avert extensively drug-resistant TB.
Clinical Implications: Routine baseline and serial DST for Group A drugs, adherence support, and rapid regimen modification are critical. Programs should enhance pharmacovigilance for bedaquiline and linezolid resistance and consider individualized regimens guided by timely DST.
Key Findings
- Treatment failure occurred in 5.3% (55/1034) with 67.1% success.
- Baseline resistance was markedly higher in failures vs successes: FQs 66.7% vs 18.3%, bedaquiline 12.5% vs 0.6%, linezolid 25.0% vs 0.6% (all p < 0.0001).
- Acquired resistance in failures: any 39.6%; bedaquiline 30.9%, linezolid 16.7%, FQs 25.0%; baseline FQ resistance (OR 4.7) and any acquired Group A resistance (OR 63.5) were strongly associated with failure.
Methodological Strengths
- Nationwide cohort leveraging surveillance data with both baseline and follow-up DST.
- Multivariable modeling quantifying associations with treatment failure.
Limitations
- Retrospective design with potential missing data and unmeasured confounders (e.g., adherence, PK variability).
- Generalizability may be limited to similar high-burden settings.
Future Directions: Implement prospective resistance surveillance with rapid DST and adherence monitoring; evaluate modified regimens and companion diagnostics to mitigate emergence of resistance.
3. Impact of nirsevimab immunoprophylaxis on respiratory syncytial virus-related outcomes in hospital and primary care after two consecutive seasons: a population-based retrospective cohort study in infants in their second year of life in Catalonia, Spain.
In a population-based cohort of 51,154 Catalan infants, nirsevimab immunization was associated with markedly lower RSV-related hospitalizations and PICU admissions over two seasons, with no evidence of rebound severity in season two. Primary care RSV infections were slightly higher in season two among immunized infants but without increased severe outcomes.
Impact: Provides robust real-world effectiveness and safety signals across consecutive seasons, informing infant RSV immunization policy and addressing concerns regarding disease rebound.
Clinical Implications: Supports broad infant nirsevimab rollout prior to first RSV season with monitoring across seasons; reinforces prioritization for hospitalization prevention without evidence for rebound severity.
Key Findings
- Among 51,154 infants, 89.9% received nirsevimab prior to or during the first season.
- By study end, RSV-related hospital admissions were 9.57 vs 35.56 per 1,000 (RR 0.27), and PICU admissions 1.90 vs 9.08 per 1,000 (RR 0.21) for immunized vs non-immunized.
- Primary care RSV infection rates were not significantly different (RR 0.81), and no significant differences in aHR across outcomes during the second season were observed.
Methodological Strengths
- Population-based design with very large sample and inverse probability-weighted Kaplan–Meier estimation.
- Assessment across two consecutive seasons with multiple clinically relevant outcomes.
Limitations
- Retrospective observational design with potential residual confounding and differential care-seeking.
- Non-randomized immunization; aHRs in season two were not statistically significant.
Future Directions: Evaluate durability, waning, and optimal timing across diverse settings; integrate genomic surveillance for RSV to monitor strain effects; economic evaluations to inform policy.