Revamping Public Health Systems: Lessons Learned From the Tripledemic

Respiratory Virus Season Surveillance in the United States Using Wastewater Metrics, 2023-2024

Wastewater measurements represent an entire contributing population and can be available within 24 h. Enhanced information about disease occurrence can improve population health through better timing of policies and interventions. We aimed to infer seasonal occurrence patterns for common respiratory viruses alongside transmission dynamics for SARS-CoV-2 across the USA using wastewater samples. We used wastewater RNA concentrations of influenza A and B (IAV/IBV), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), and SARS-CoV-2 from 175 treatment plants (July 2023-June 2024). For IAV, IBV, RSV, and HMPV, we determined epidemic onset, offset, peak, and duration at national and subnational scales. For SARS-CoV-2, we categorized wastewater measurements based on recent wastewater levels and trends. Epidemic onset occurred in November for IAV and RSV which aligned with prepandemic norms. Onset occurred in January for IBV and April for HMPV which were later than expected according to historical data. Duration was longer for IAV and shorter for IBV, RSV, and HMPV than expected based on historical data. Epidemic peak dates were consistent with prepandemic norms for all viruses. Peak dates for influenza and RSV coincided with high, upward trending SARS-CoV-2 RNA concentrations, suggesting potential co-occurrence of SARS-CoV-2 with these viruses.

Respiratory Syncytial Virus: A WAidid Consensus Document on New Preventive Options

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of respiratory infections, particularly affecting young infants, older adults, and individuals with comorbidities. Methods: This document, developed as a consensus by an international group of experts affiliated with the World Association of Infectious Diseases and Immunological Disorders (WAidid), focuses on recent advancements in RSV prevention, highlighting the introduction of monoclonal antibodies (mAbs) and vaccines. Results: Historically, RSV treatment options were limited to supportive care and the monoclonal antibody palivizumab, which required multiple doses. Recent innovations have led to the development of long-acting mAbs, such as nirsevimab, which provide season-long protection with a single dose. Nirsevimab has shown high efficacy in preventing severe RSV-related lower respiratory tract infections (LRTIs) in infants, reducing hospitalizations and ICU admissions. Additionally, new vaccines, such as RSVpreF and RSVpreF3, target older adults and have demonstrated significant efficacy in preventing LRTIs in clinical trials. Maternal vaccination strategies also show promise in providing passive immunity to newborns, protecting them during the most vulnerable early months of life. This document further discusses the global burden of RSV, its economic impact, and the challenges of implementing these preventative strategies in different healthcare settings. Conclusions: The evidence supports the integration of both passive (mAbs) and active (vaccines) immunization approaches as effective tools to mitigate the public health impact of RSV. The combined use of these interventions could substantially reduce RSV-related morbidity and mortality across various age groups and populations, emphasizing the importance of widespread immunization efforts.

Performance Assessment of a Multiplex Real-Time PCR Assay for Detection of Viruses Causing Respiratory Tract Infections

OBJECTIVES

Following the COVID-19 pandemic, global epidemiological trends demonstrate a return to pre-pandemic levels of respiratory syncytial virus (RSV) and influenza (Flu) A/B viruses. For the appropriate clinical management of viral infections, reliable and timely diagnosis is crucial. The clinical presentation of these respiratory viral infections shows significant overlaps; thus, the syndromic diagnosis of these infections becomes challenging. The goal of this study was to compare the performance of three multiplex real-time PCR-based platforms for the detection of SARS-CoV-2, Flu A, Flu B, and RSV.

MATERIALS AND METHODS

A retrospective study was performed on 200 de-identified nasopharyngeal and oropharyngeal specimens. All samples were tested simultaneously on three PCR-based platforms for the detection of SARS-CoV-2, Flu A, Flu B, and RSV: HealthTrackRx's real-time PCR Open Array® respiratory panel, TrueMark™ SARS-CoV-2, Flu A, Flu B, RSV Select Panel, and BioFire® RP2.1 Panel. The positive and negative predictive value of each test was evaluated at a 95% confidence interval.

RESULTS

Among the 200 tested samples, the TrueMark™ and OpenArray® laboratory-developed tests (LDTs) showed a 100% concordance for the detection of SARS-CoV-2, Flu A, Flu B, and RSV. Overall agreement of 100% was observed for nasopharyngeal samples between the laboratory-developed tests and FDA-approved BioFire® RP2.1 Panel. Diagnostic results for these four respiratory viruses, in clinical samples, between the LDTs and the FDA-approved comparator demonstrated full concordance.

CONCLUSIONS

Respiratory viral infections represent one of the major global healthcare burdens. Consequently, the accurate detection and surveillance of these viruses are critical, particularly when these viruses are known to co-circulate. The excellent performance and full concordance of the LDTs, with the BioFire® Respiratory RP2.1 panel, in detecting SARS-CoV-2, Flu A, Flu B, and RSV shows that these tests can be confidently implemented for the clinical testing of respiratory viral infections.

Supporting vaccine (co)-administration decisions: Development and validation of a tool for assessing the risk of severe outcomes due to lower respiratory tract infections

OBJECTIVE

To develop and validate a score to predict the 90-day risk of hospitalization/death in patients with low respiratory tract infections (LRTIs) with the aim to support clinical decision making on vaccine (co)-administration.

METHODS

We formed a cohort of patients aged 18 years or older being diagnosed with LRTIs in the period between January 1, 2012 and December 31, 2022. Each patient was followed until occurrence of respiratory-related hospitalization/death up to the end of the study period (December 31, 2022). Along with age and sex, forty determinants were adopted to assemble the respiratory tract infection (RTI)-Health Search (HS) core using the development sub-cohort. The prediction accuracy of the score was therefore assessed in the validation sub-cohort.

RESULTS

We identified 252,319 patients being diagnosed with LRTIs (females: 54.7 %; mean age: 60 (SD:18.1)). When the risk of LRTIs-related hospitalizations/deaths was estimated via RTI-HScore, its predicted value was equal to 1.4 % over a 90-day event horizon. The score showed explained variation and discrimination accuracy were equal to 45 % (95 % CI: 44-47 %) and 81 % (95 % CI: 79-84 %), respectively. The calibration slope did not significantly differ from the unit (p = 0.8314).

CONCLUSIONS

The RTI-HScore was featured by good accuracy for prediction of LRTIs-related complications over a 90-day follow-up. Such a tool might therefore support general practitioners to enhance patients' care by facilitating approaches for (co)-administration of vaccines for respiratory infections through a score-based decision support system.

Impact of Nirsevimab Immunization on Pediatric Hospitalization Rates: A Systematic Review and Meta-Analysis (2024)

A systematic review with a meta-analysis was performed to gather available evidence on the effectiveness of monoclonal antibody nirsevimab in the prevention of lower respiratory tract diseases (LRTDs) due to respiratory syncytial virus (RSV) in children and newborns (CRD42024540669). Studies reporting on real-world experience and randomized controlled trials (RCTs) were searched for in three databases (PubMed, Embase, and Scopus) until 1 May 2024. Our analysis included five RCTs, seven real-world reports, and one official report from the health authorities. Due to the cross-reporting of RCTs and the inclusion of multiple series in a single study, the meta-analysis was performed on 45,238 infants from 19 series. The meta-analysis documented a pooled immunization efficacy of 88.40% (95% confidence interval (95% CI) from 84.70 to 91.21) on the occurrence of hospital admission due to RSV, with moderate heterogeneity (I2 24.3%, 95% CI 0.0 to 56.6). Immunization efficacy decreased with the overall length of the observation time (Spearman's r = -0.546, p = 0.016), and the risk of breakthrough infections was substantially greater in studies with observation times ≥150 days compared to studies lasting <150 days (risk ratio 2.170, 95% CI 1.860 to 2.532). However, the effect of observation time in meta-regression analysis was conflicting (β = 0.001, 95% CI -0.001 to 0.002; p = 0.092). In conclusion, the delivery of nirsevimab was quite effective in preventing hospital admissions due to LRTDs. However, further analyses of the whole RSV season are required before tailoring specific public health interventions.

Efficacy of Respiratory Syncytial Virus Vaccination to Prevent Lower Respiratory Tract Illness in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

A systematic review and meta-analysis was designed in order to ascertain the effectiveness of respiratory syncytial virus (RSV) vaccination in preventing lower respiratory tract diseases (LRTD) in older adults (age ≥ 60 years). Studies reporting on randomized controlled trials (RCTs) were searched for in three databases (PubMed, Embase, and Scopus) and the preprint repository medRxiv until 31 March 2024. A total of nine studies were eventually included, two of which were conference proceedings. Our analysis included five RCTs on five RSV vaccines (RSVpreF, RSVPreF3, Ad26.RSV.preF, MEDI7510, and mRNA-1345). The meta-analysis documented a pooled vaccine efficacy of 81.38% (95% confidence interval (95% CI) 70.94 to 88.06) for prevention of LRTD with three or more signs/symptoms during the first RSV season after the delivery of the vaccine. Follow-up data were available for RSVPreF3 (2 RSV seasons), RSVpreF (mid-term estimates of second RSV season), and mRNA-1345 (12 months after the delivery of the primer), with a pooled VE of 61.15% (95% CI 45.29 to 72.40). After the first season, the overall risk for developing RSV-related LRTD was therefore substantially increased (risk ratio (RR) 4.326, 95% CI 2.415; 7.748). However, all estimates were affected by substantial heterogeneity, as suggested by the 95% CI of I2 statistics, which could be explained by inconsistencies in the design of the parent studies, particularly when dealing with case definition. In conclusion, adult RSV vaccination was quite effective in preventing LRTD in older adults, but the overall efficacy rapidly decreased in the second season after the delivery of the vaccine. Because of the heterogenous design of the parent studies, further analyses are required before tailoring specific public health interventions.

Respiratory Syncytial Virus Infections in Recipients of Bone Marrow Transplants: A Systematic Review and Meta-Analysis

Human Respiratory Syncytial Virus (RSV) is a common cause of respiratory tract infections. Usually associated with infants and children, an increasing amount of evidence suggests that RSV can cause substantial morbidity and mortality in immunocompromised individuals, including recipients of bone marrow transplantation (BMT). The present systematic review was therefore designed in accordance with the PRISMA guidelines to collect available evidence about RSV infections in BMT recipients. Three medical databases (PubMed, Embase, and MedRxiv) were therefore searched for eligible observational studies published up to 30 September 2023 and collected cases were pooled in a random-effects model. Heterogeneity was assessed using I2 statistics. Reporting bias was assessed by means of funnel plots and regression analysis. Overall, 30 studies were retrieved, including 20,067 BMT cases and 821 RSV infection episodes. Of them, 351 were lower respiratory tract infections, and a total of 78 RSV-related deaths were collected. A pooled attack rate of 5.40% (95% confidence interval [95%CI] 3.81 to 7.60) was identified, with a corresponding incidence rate of 14.77 cases per 1000 person-years (95%CI 9.43 to 20.11), and a case fatality ratio (CFR) of 7.28% (95%CI 4.94 to 10.60). Attack rates were higher in adults (8.49%, 95%CI 5.16 to 13.67) than in children (4.79%, 95%CI 3.05 to 7.45), with similar CFR (5.99%, 95%CI 2.31 to 14.63 vs. 5.85%, 95%CI 3.35 to 10.02). By assuming RSV attack rates as a reference group, influenza (RR 0.518; 95%CI 0.446 to 0.601), adenovirus (RR 0.679, 95%CI 0.553 to 0.830), and human metapneumovirus (RR 0.536, 95%CI 0.438 to 0.655) were associated with a substantially reduced risk for developing corresponding respiratory infection. Despite the heterogeneous settings and the uneven proportion of adult and pediatric cases, our study has identified high attack rates and a substantial CFR of RSV in recipients of BMT, stressing the importance of specifically tailored preventive strategies and the need for effective treatment options.

Respiratory Syncytial Virus, Influenza and SARS-CoV-2 in Homeless People from Urban Shelters: A Systematic Review and Meta-Analysis (2023)

Homeless people (HP) are disproportionally affected by respiratory disorders, including pneumococcal and mycobacterial infections. On the contrary, more limited evidence has been previously gathered on influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and very little is known about the occurrence of human respiratory syncytial virus (RSV), a common cause of respiratory tract infections among children and the elderly. The present systematic review was designed to collect available evidence about RSV, influenza and SARS-CoV-2 infections in HP, focusing on those from urban homeless shelters. Three medical databases (PubMed, Embase and Scopus) and the preprint repository medRxiv.org were therefore searched for eligible observational studies published up to 30 December 2023, and the collected cases were pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics. Reporting bias was assessed by funnel plots and a regression analysis. Overall, 31 studies were retrieved, and of them, 17 reported on the point prevalence of respiratory pathogens, with pooled estimates of 4.91 cases per 1000 HP (95%CI: 2.46 to 9.80) for RSV, 3.47 per 1000 HP for influenza and 40.21 cases per 1000 HP (95%CI: 14.66 to 105.55) for SARS-CoV-2. Incidence estimates were calculated from 12 studies, and SARS-CoV-2 was characterized by the highest occurrence (9.58 diagnoses per 1000 persons-months, 95%CI: 3.00 to 16.16), followed by influenza (6.07, 95%CI: 0.00 to 15.06) and RSV (1.71, 95%CI: 0.00 to 4.13). Only four studies reported on the outcome of viral infections in HP: the assessed pathogens were associated with a high likelihood of hospitalization, while high rates of recurrence and eventual deaths were reported in cases of RSV infections. In summary, RSV, influenza and SARS-CoV-2 infections were documented in HP from urban shelters, and their potential outcomes stress the importance of specifically tailored preventive strategies.