Daily Respiratory Research Analysis
Three impactful studies reshape respiratory infectious disease control: a Lancet Infectious Diseases RCT shows that 8-week tuberculosis regimens increase relapse versus standard therapy, emphasizing the need for post-treatment monitoring if used. A multicenter diagnostic study demonstrates high-accuracy noninvasive tongue-swab PCR and targeted NGS for TB and drug resistance. An integrated wastewater study links respiratory virus loads with pharmacy markers to quantify symptom treatment and uncov
Summary
Three impactful studies reshape respiratory infectious disease control: a Lancet Infectious Diseases RCT shows that 8-week tuberculosis regimens increase relapse versus standard therapy, emphasizing the need for post-treatment monitoring if used. A multicenter diagnostic study demonstrates high-accuracy noninvasive tongue-swab PCR and targeted NGS for TB and drug resistance. An integrated wastewater study links respiratory virus loads with pharmacy markers to quantify symptom treatment and uncover unmonitored outbreaks.
Research Themes
- TB regimen shortening and relapse risk
- Noninvasive TB diagnostics with tongue swabs and tNGS
- Integrated wastewater surveillance for respiratory pathogens and symptom treatment
Selected Articles
1. Efficacy and safety of 8-week regimens for the treatment of rifampicin-susceptible pulmonary tuberculosis (TRUNCATE-TB): a prespecified exploratory analysis of a multi-arm, multi-stage, open-label, randomised controlled trial.
In this prespecified analysis of the TRUNCATE-TB RCT (n=674 ITT), 8-week regimens had higher unfavorable outcomes (mostly relapse) than standard 24-week therapy. The bedaquiline+linezolid regimen had a smaller difference (adjusted +9.3%) than high-dose rifampicin+linezolid (+21.0%). Grade 3–4 adverse events were similar across groups.
Impact: This large, well-conducted RCT provides definitive evidence that 8-week TB regimens increase relapse risk versus standard therapy, while informing which shortened regimen performs relatively better.
Clinical Implications: Eight-week regimens should not be used as routine replacements for standard therapy; if deployed, they require structured post-treatment monitoring and prompt re-treatment. Bedaquiline-linezolid performed best among shortened regimens but still had inferior efficacy.
Key Findings
- Unfavorable outcome: 4% with standard therapy vs 25% with high-dose rifampicin+linezolid (adjusted difference 21.0%, 95% BCI 14.3–28.1)
- Unfavorable outcome: 14% with bedaquiline+linezolid (adjusted difference 9.3%, 95% BCI 4.3–14.9)
- Grade 3–4 adverse events: 14% (standard) vs 11% (rifampicin+linezolid) vs 12% (bedaquiline+linezolid)
Methodological Strengths
- Multi-arm, multi-stage randomized controlled design with prespecified analysis
- Bayesian estimation of differences and intention-to-treat analysis across regimens
Limitations
- Open-label design may introduce performance bias
- Exploratory focus on 8-week regimens; not powered to compare all regimens head-to-head
Future Directions: Optimize shortened regimens (e.g., longer than 8 weeks, or alternative drug combinations) and evaluate implementation with structured relapse surveillance.
BACKGROUND: WHO recommends a 2-month optimal duration for new drug regimens for rifampicin-susceptible tuberculosis. We aimed to investigate the efficacy and safety of the 8-week regimens that were assessed as part of the TRUNCATE management strategy of the TRUNCATE-TB trial. METHODS: TRUNCATE-TB was a multi-arm, multi-stage, open-label, randomised controlled trial in which participants aged 18-65 years with rifampicin-susceptible pulmonary tuberculosis were randomly assigned via a web-based system, using permuted blocks, to 24-week standard treatment (rifampicin, isoniazid, pyrazinamide, and ethambutol) or the TRUNCATE management strategy comprising initial 8-week treatment, then post-treatment monitoring and re-treatment where needed. The four 8-week regimens comprised five drugs, modified from standard treatment: high-dose rifampicin and linezolid, or high-dose rifampicin and clofazimine, or bedaquiline and linezolid, all given with isoniazid, pyrazinamide, and ethambutol; and rifapentine, linezolid, and levofloxacin, given with isoniazid and pyrazinamide. Here, we report the efficacy (proportion with unfavourable outcome; and difference from standard treatment, assessed via Bayesian methods) and safety of the 8-week regimens, assessed in the intention-to-treat population. This prespecified exploratory analysis is distinct from the previously reported 96-week outcome of the strategy in which the regimens were deployed. This trial is registered with ClinicalTrials.gov (NCT03474198). FINDINGS: Between March 21, 2018, and March 26,
2. Insights into respiratory illness at the population level through parallel analysis of pharmaceutical and viral markers in wastewater.
Across ten Swiss catchments (23% population, 2021–2024), loads of cough/fever/pain pharmaceuticals (e.g., dextromethorphan, acetaminophen, codeine) strongly correlated with SARS-CoV-2, RSV, and influenza A/B signals in wastewater. Periods with elevated pharmaceuticals but low viral loads indicated symptomatic illness from unmonitored pathogens.
Impact: This study pioneers integrated wastewater surveillance linking pharmaceutical markers with respiratory viral loads, enabling quantification of symptom treatment and detection of outbreaks beyond existing surveillance.
Clinical Implications: Public health programs can complement virological wastewater monitoring with pharmaceutical markers to gauge community symptom burden, guide healthcare resource allocation, and flag untracked respiratory outbreaks.
Key Findings
- Strong correlations between virus loads (SARS-CoV-2, RSV, influenza A/B) and pharmaceuticals (e.g., dextromethorphan, acetaminophen, codeine, pheniramine, clarithromycin)
- Pharmaceutical-only surges (2021, 2024) without viral increases marked symptomatic illness likely due to unsurveilled pathogens
- Feasibility of estimating pathogen-specific and cumulative symptom treatment at population scale
Methodological Strengths
- Multi-site, multi-year longitudinal wastewater surveillance covering 23% of national population
- Parallel measurement of four respiratory viruses and 15 pharmaceuticals enabling cross-signal validation
Limitations
- Ecological data cannot attribute pharmaceuticals to specific clinical diagnoses
- Potential confounding from non-respiratory uses of some pharmaceuticals and seasonal behaviors
Future Directions: Standardize integrated wastewater surveillance, expand panels to additional pathogens/symptom markers, and link with clinical data to improve outbreak attribution and forecasting.
Wastewater as a medium contains information on both circulating pathogens and drug consumption at the population level. This study combines tracking of respiratory viruses and quantification of pharmaceuticals as untargeted indicators of symptoms related to acute respiratory infections and influenza-like illnesses such as coughing, fever and pain. From January 2021 to June 2024, raw wastewater samples from ten locations covering 23% of the Swiss population were analysed. This encompassed 15 pharmaceuticals and four priority respiratory viruses including severe acute respiratory syndrome coronavirus virus-2 (SARS-CoV-2), respiratory syncytial virus (RSV), influenza A and influenza B viruses. The pharmaceutical compounds dextromethorphan, pheniramine, clarithromycin, acetaminophen and codeine showed a strong correlation with respiratory virus loads in wastewater. This enabled the estimation of pathogen-specific and cumulative symptom treatment in the population. In 2021 and 2024, notable increases in pharmaceutical loads without corresponding increases in viral loads signalled high community symptoms linked to unsurveilled pathogens. This study demonstrates that pharmaceutical surveillance can inform respiratory disease burden and highlights the value of integrated surveillance for assessing emerging public health threats beyond those routinely monitored.
3. Tongue swab-based molecular diagnostics for pulmonary tuberculosis and drug resistance in adults: A prospective multicenter diagnostic accuracy study.
In five Chinese TB hospitals (n=720), tongue-swab PCR showed sensitivity 88.6% and specificity 98.3% versus microbiologic reference standards, and 95.1% concordance with Xpert. Targeted NGS on tongue swabs reliably detected drug resistance at lower Ct thresholds, supporting noninvasive resistance profiling.
Impact: Provides strong multicenter evidence that tongue swabs can accurately diagnose pulmonary TB and support resistance detection, enabling broader case finding where sputum collection is difficult.
Clinical Implications: Integrate tongue swab PCR and tNGS into TB diagnostic pathways for patients unable to expectorate or with paucibacillary disease; may facilitate community screening and resistance surveillance.
Key Findings
- Diagnostic accuracy vs microbiological reference: sensitivity 88.6% (95% CI 85.3–91.8), specificity 98.3% (95% CI 97.0–99.7)
- Concordance with Xpert MTB/RIF: 95.1% (95% CI 93.2–96.5)
- tNGS resistance detection rates by Ct: 98.66% (<30), 91.53% (30–33), 84.62% (33–34), 57.14% (34–35)
Methodological Strengths
- Prospective multicenter design across five TB-designated hospitals
- Head-to-head comparison with microbiological reference standards and Xpert
Limitations
- All participants could provide sputum; real-world performance in sputum-scarce settings needs confirmation
- Ct-dependent tNGS performance may limit resistance detection at low pathogen loads
Future Directions: Optimize swab collection and amplification to improve yield at higher Ct, assess community-based implementation, and evaluate cost-effectiveness.
BACKGROUND: Tongue swabs have emerged as a promising non-invasive alternative for TB diagnosis. This study aimed to evaluate the diagnostic performance of tongue swab-based assays for detecting Mycobacterium tuberculosis (MTB) and anti-TB drug resistance. METHODS: We conducted a multicenter study in five TB-designated hospitals in China from May to August 2024. Tongue swabs and sputum samples were collected from 720 adults with symptoms suggestive of pulmonary TB. PCR-based tongue swab testing targeting MTB-specific sequences was evaluated against microbiological reference standards (MRS) and Xpert MTB/RIF. Tongue swab-based targeted next generation sequencing was conducted to diagnose the drug-resistant TB. RESULTS: Tongue swab testing demonstrated high diagnostic accuracy, with a concordance rate of 95.1% (95% CI: 93.2-96.5) compared to Xpert MTB/RIF, and with a sensitivity of 88.6% (95% CI: 85.3-91.8) and specificity of 98.3% (95% CI: 97.0-99.7) compared to MRS. Tongue swabs supported the detection of drug-resistant MTB using targeted next-generation sequencing, with detection rates of 98.66% for Ct <30, 91.53% for Ct 30-33, and 84.62% for Ct 33-34, declining sharply to 57.14% for Ct 34-35. CONCLUSION: PCR-based tongue swab testing offers a rapid, non-invasive alternative for TB diagnosis with high accuracy, particularly in paucibacillary cases or individuals unable to provide sputum. Although all participants in this study were able to provide sputum, tongue swabs may offer an alternative in situations where sputum collection is challenging. Further optimization of sampling and molecular techniques is essential to improve reliability and support broader implementation. Integrating tongue swab diagnostics with existing TB control programs could enhance the detection accuracy, improve drug resistance monitoring and reduce transmissions.