Daily Ards Research Analysis
Three clinically oriented studies stand out today. A Swedish target trial emulation across 575,817 births maps gestational-age thresholds that minimize neonatal respiratory distress risk for induction and elective cesarean. Norway’s nationwide registry-based SARI surveillance demonstrates timely, multi-pathogen nowcasting utility, while Argentina’s multicenter RSV cohort details post-pandemic seasonality shifts and high-risk predictors supporting maternal immunization strategies.
Summary
Three clinically oriented studies stand out today. A Swedish target trial emulation across 575,817 births maps gestational-age thresholds that minimize neonatal respiratory distress risk for induction and elective cesarean. Norway’s nationwide registry-based SARI surveillance demonstrates timely, multi-pathogen nowcasting utility, while Argentina’s multicenter RSV cohort details post-pandemic seasonality shifts and high-risk predictors supporting maternal immunization strategies.
Research Themes
- Optimal timing of planned birth to reduce neonatal respiratory distress
- Real-time surveillance for severe respiratory infections (SARI) including ARDS
- Post-pandemic RSV epidemiology and maternal immunization implications
Selected Articles
1. Respiratory distress after planned births compared to expectant management - Target trial emulation.
In a target trial emulation of 575,817 Swedish singleton births, induction of labor carried no excess neonatal respiratory distress risk from 38 weeks onward, whereas elective cesarean reached risk neutrality only from 40 weeks. Earlier elective cesarean was associated with markedly higher absolute and relative risks and increased odds of Apgar <7.
Impact: This analysis provides actionable gestational-age thresholds to minimize respiratory morbidity from planned births, potentially informing national policies and scheduling practices. The day-by-day risk estimates strengthen individualized decision-making.
Clinical Implications: Prefer induction from ≥38 weeks and elective cesarean from ≥40 weeks when medically reasonable to reduce neonatal respiratory distress and low Apgar risk. Avoid early elective cesarean (<38 weeks) without compelling indications.
Key Findings
- No excess respiratory distress risk for induction from 38 weeks and for elective cesarean from 40 weeks versus expectant management.
- At 37 weeks, absolute respiratory distress risk was 12.4% for elective cesarean (aRR 5.7, 95% CI 4.8–6.5) and 4.0% for induction (aRR 1.7, 95% CI 1.5–2.0).
- Elective cesarean at 39 weeks had 3.2% absolute risk (aRR 1.6, 95% CI 1.3–1.8), and elective cesarean <38 weeks increased risk of Apgar <7.
Methodological Strengths
- Nationwide, very large registry-based cohort with day-by-day gestational-age risk estimation
- Target trial emulation design with adjusted relative risks
Limitations
- Observational registry study susceptible to residual confounding and indication bias
- Generalizability may be limited outside Sweden; exclusions may omit higher-risk populations
Future Directions: Replicate in other health systems; integrate maternal outcomes and stratify by indications; assess impacts of policy changes on respiratory morbidity.
OBJECTIVE: The primary aim of this study was to determine the appropriate gestational age for planned births by elective cesarean section (ECS) or induction of labor (IOL) in relation to no excess risk of neonatal respiratory distress. STUDY DESIGN: Register-based Swedish cohort study including 575,817 singleton live births at 36 weeks or later. Births not eligible for vaginal delivery, preterm premature rupture of membranes and infants with congenital anomalies were excluded. The primary outcome was respiratory distress, and a secondary outcome was Apgar score <7 at five minutes. The risk of outcomes according to onset of birth was calculated for each day from gestational week 36 to 41 and compared with expectant management (EM), defined as births at least one day later.
2. Registry-Based Surveillance of Severe Acute Respiratory Infections in Norway During 2021-2024.
Among 214,730 SARI cases, testing coverage was high (82% SARS-CoV-2, 73% influenza, 53% RSV) and epidemic peaks were driven by these pathogens. Median time to ICD-10 coding was 5 days, while nowcasting and alternative case definitions improved timeliness, especially in younger populations where including URIs increased capture.
Impact: Demonstrates scalable, registry-based SARI surveillance integrating PCR data and nowcasting to support rapid situational awareness and resource allocation. It provides a blueprint for permanent national systems.
Clinical Implications: Implement permanent registry-based SARI surveillance with nowcasting to detect surges early, guide ICU capacity, and tailor responses across age groups; include URI codes to improve case capture in younger populations.
Key Findings
- Identified 214,730 SARI cases; testing coverage was 82% for SARS-CoV-2, 73% for influenza, and 53% for RSV.
- Median time from admission to SARI ICD-10 coding was 5 days (IQR 3–10); nowcasting and alternative case definitions improved timeliness.
- ICD-10 codes for LRIs and COVID-19 captured only ~55% of cases in ages 0–29 compared with definitions including URIs.
Methodological Strengths
- Nationwide linkage of administrative and laboratory PCR datasets across multiple pathogens
- Formal evaluation of timeliness and impact of alternative case definitions including nowcasting
Limitations
- Dependent on coding accuracy and completeness; limited clinical granularity and severity metrics
- Temporary system; external validity to other health systems may vary
Future Directions: Establish permanent SARI surveillance with real-time dashboards; integrate outcomes (ICU, mortality), vaccination status, and genomic data to refine attribution and forecasting.
BACKGROUND: In 2021, the Norwegian Institute of Public Health established temporary registry-based surveillance of severe acute respiratory infections (SARI). We aimed to describe the surveillance system and evaluate selected attributes to inform the establishment of a permanent SARI surveillance system. METHODS: SARI cases were defined using ICD-10 discharge codes from national health and administrative registries, including codes for acute upper or lower respiratory infection (URI and LRI), COVID-19, acute respiratory distress syndrome, pertussis or otitis media. Data from polymerase chain reaction (PCR) analyses were available for 10 respiratory pathogens including SARS-CoV-2, influenza virus and respiratory syncytial virus (RSV). We included data from 28 September 2020 to 31 March 2024 and calculated the following parameters: the proportion of cases tested for SARS-CoV-2, influenza virus and/or RSV; time between admission and registration of a SARI-related ICD-10 code; and proportion of cases with URI, LRI and COVID-19.
3. Respiratory Syncytial Virus Epidemiology in Argentina: From COVID-19 Pandemic to the Maternal Immunization Strategy.
Across 5 tertiary centers, 5,838 pediatric LRTI admissions were analyzed: RSV remained the most prevalent virus, though post-pandemic shifts included decreased RSV and increased parainfluenza and hMPV, with a 6-week seasonality shift. Seventy-one percent of RSV cases were <12 months; prematurity, comorbidities, and age <6 months independently predicted RSV infection.
Impact: Findings inform maternal immunization and infant prophylaxis strategies by quantifying post-pandemic RSV dynamics, risk factors, and ICU needs in a middle-income setting.
Clinical Implications: Prioritize maternal RSV vaccination and infant prophylaxis for <6 months, preterm infants, and those with comorbidities; anticipate earlier season onset and adjust PICU and testing capacity; reduce unnecessary antibiotics.
Key Findings
- Among 5,838 pediatric LRTI admissions, 66.4% were virus-positive; RSV was most prevalent with 17.2% coinfection rate among RSV cases.
- Post-pandemic period showed decreased RSV and increased parainfluenza and hMPV; seasonality shifted 6 weeks and RSV recovered with earlier onset in 2023.
- Independent predictors of RSV infection: prematurity (OR 1.3, 95% CI 1.1–1.5), comorbidities (OR 1.8, 95% CI 1.6–2), and age <6 months (OR 1.8, 95% CI 1.6–2.1).
Methodological Strengths
- Prospective multicenter design with large sample and standardized PCR diagnostics
- Comparative analysis across pre- and post-pandemic periods with multivariable modeling
Limitations
- Limited to five tertiary centers; selection bias and regional generalizability concerns
- Diagnostic methods differed across periods (indirect assays vs PCR) potentially affecting detection rates
Future Directions: Assess maternal RSV vaccine impact and nirsevimab rollout on admissions and ICU use; employ time-series models for seasonality forecasting and resource planning.
INTRODUCTION: Worldwide, respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections (LRTIs) and hospital admissions among infants and young children. The COVID-19 pandemic changed the epidemiology and clinical patterns of respiratory viruses other than severe acute respiratory syndrome coronavirus 2. Argentina introduced the RSV maternal vaccine in 2024. This multicenter study describes the clinical-epidemiological profile of hospitalized pediatric patients with LRTI associated with RSV in Argentina, comparing pre- and postpandemic periods, and identifies independent predictors of RSV infection. MATERIALS AND METHODS: This prospective, multicenter study included patients under 18 years old admitted for LRTI in 5 tertiary centers in Argentina before (2018-2019) and after (2022-2023) COVID-19.