Can Analysis of Routine Viral Testing Provide Accurate Estimates of Respiratory Syncytial Virus Disease Burden in Adults?

Disease burden and high-risk populations for complications in patients with acute respiratory infections: a scoping review

Background

Acute respiratory infections (ARIs) represent a significant public health concern in the U.S. This study aimed to describe the disease burden of ARIs and identify U.S. populations at high risk of developing complications.

Methods

This scoping review searched PubMed and EBSCO databases to analyze U.S. studies from 2013 to 2022, focusing on disease burden, complications, and high-risk populations associated with ARIs.

Results

The study included 60 studies and showed that ARI is associated with a significant disease burden and healthcare resource utilization (HRU). In 2019, respiratory infection and tuberculosis caused 339,703 cases per 100,000 people, with most cases being upper respiratory infections and most deaths being lower respiratory infections. ARI is responsible for millions of outpatient visits, especially for influenza and pneumococcal pneumonia, and indirect costs of billions of dollars. ARI is caused by multiple pathogens and poses a significant burden on hospitalizations and outpatient visits. Risk factors for HRU associated with ARI include age, chronic conditions, and socioeconomic factors.

Conclusion

The review underscores the substantial disease burden of ARIs and the influence of age, chronic conditions, and socioeconomic status on developing complications. It highlights the necessity for targeted strategies for high-risk populations and effective pathogen detection to prevent severe complications and reduce HRU.

Estimated Respiratory Syncytial Virus-Related Hospitalizations and Deaths Among Children and Adults in Spain, 2016-2019

INTRODUCTION

Respiratory syncytial virus (RSV) causes a substantial disease burden among infants. In older children and adults, incidence is underestimated due to nonspecific symptoms and limited standard-of-care testing. We aimed to estimate RSV-attributable hospitalizations and deaths in Spain during 2016-2019.

METHODS

Nationally representative hospitalization and mortality databases were obtained from the Ministry of Health and the National Statistical Office. A quasi-Poisson regression model was fitted to estimate the number of hospitalizations and deaths attributable to RSV as a function of periodic and aperiodic time trends and viral activity, while allowing for potential overdispersion.

RESULTS

In children, the RSV-attributable respiratory hospitalization incidence was highest among infants aged 0-5 months (3998-5453 cases/100,000 person-years, representing 72% of all respiratory hospitalizations) and decreased with age. In 2019, estimated rates in children 0-5, 6-11, 12-23 months and 6-17 years were approximately 1.3, 1.4, 1.5, and 6.5 times higher than those based on standard-of-care RSV-specific codes. In adults, the RSV-attributable cardiorespiratory hospitalization rate increased with age and was highest among persons ≥ 80 years (1325-1506 cases/100,000, 6.5% of all cardiorespiratory hospitalizations). In 2019, for persons aged 18-49, 50-59, 60-79, and ≥ 80 years, estimated rates were approximately 8, 6, 8, and 16 times higher than those based on standard-of-care RSV-specific codes. The RSV-attributable cardiorespiratory mortality rate was highest among ≥ 80 age group (126-150 deaths/100,000, 3.5-4.1% of all cardiorespiratory deaths), when reported mortality rate ranged between 0 and 0.5/100,000.

CONCLUSIONS

When accounting for under-ascertainment, estimated RSV-attributable hospitalizations were higher than those reported based on standard-of-care RSV-specific codes in all age groups but particularly among older children and older adults. Like other respiratory viruses, RSV contributes to both respiratory and cardiovascular complications. Efficacious RSV vaccines could have a high public health impact in these age and risk groups.

Burden of illness associated with Respiratory Syncytial Virus (RSV)-related hospitalizations among adults in Ontario, Canada: A retrospective population-based study

BACKGROUND

Globally, RSV is a common viral pathogen that causes 64 million acute respiratory infections annually. Our objective was to determine the incidence of hospitalization, healthcare resource use and associated costs of adults hospitalized with RSV in Ontario, Canada.

METHODS

To describe the epidemiology of adults hospitalized with RSV, we used a validated algorithm applied to a population-based healthcare utilization administrative dataset in Ontario, Canada. We created a retrospective cohort of incident hospitalized adults with RSV between September 2010 and August 2017 and followed each person for up to two years. To determine the burden of illness associated with hospitalization and post-discharge healthcare encounters each RSV-admitted patient was matched to two unexposed controls based on demographics and risk factors. Patient demographics were described and mean attributable 6-month and 2-year healthcare costs (2019 Canadian dollars) were estimated.

RESULTS

There were 7,091 adults with RSV-associated hospitalizations between 2010 and 2019 with a mean age of 74.6 years; 60.4 % were female. RSV-coded hospitalization rates increased from 1.4 to 14.6 per 100,000 adults between 2010-2011 and 2018-2019. The mean difference in healthcare costs between RSV-admitted patients and matched controls was $28,260 (95 % CI: $27,728 - $28,793) in the first 6 months and $43,721 over 2 years (95 % CI: $40,383 - $47,059) post-hospitalization.

CONCLUSIONS

RSV hospitalizations among adults increased in Ontario between 2010/11 to 2018/19 RSV seasons. RSV hospitalizations in adults were associated with increased attributable short-term and long-term healthcare costs compared to matched controls. Interventions that could prevent RSV in adults may reduce healthcare burden.

Clinical impact of healthcare-associated respiratory syncytial virus in hospitalized adults

OBJECTIVE

To describe the clinical impact of healthcare-associated (HA) respiratory syncytial virus (RSV) in hospitalized adults.

DESIGN

Retrospective cohort study within a prospective, population-based, surveillance study of RSV-infected hospitalized adults during 3 respiratory seasons: October 2017-April 2018, October 2018-April 2019, and October 2019-March 2020.

SETTING

The study was conducted in 2 academically affiliated medical centers.

PATIENTS

Each HA-RSV patient (in whom RSV was detected by PCR test ≥4 days after hospital admission) was matched (age, sex, season) with 2 community-onset (CO) RSV patients (in whom RSV was detected ≤3 days of admission).

METHODS

Risk factors and outcomes were compared among HA-RSV versus CO-RSV patients using conditional logistic regression. Escalation of respiratory support associated with RSV detection (day 0) from day -2 to day +4 was explored among HA-RSV patients.

RESULTS

In total, 84 HA-RSV patients were matched to 160 CO-RSV patients. In HA-RSV patients, chronic kidney disease was more common, while chronic respiratory conditions and obesity were less common. HA-RSV patients were not more likely to be admitted to an ICU or require mechanical ventilation, but they more often required a higher level of care at discharge compared with CO-RSV patients (44% vs 14%, respectively). Also, 29% of evaluable HA-RSV patients required respiratory support escalation; these patients were older and more likely to have respiratory comorbidities, to have been admitted to intensive care, and to die during hospitalization.

CONCLUSIONS

HA-RSV in adults may be associated with escalation in respiratory support and an increased level of support in living situation at discharge. Infection prevention and control strategies and RSV vaccination of high-risk adults could mitigate the risk of HA-RSV.

Perturbations in Respiratory Syncytial Virus Activity During the SARS-CoV-2 Pandemic

Respiratory syncytial virus (RSV) is a common cause of respiratory disease in all age groups, with young children and older adults experiencing the most severe illness. The coronavirus disease 2019 (COVID-19) pandemic resulted in striking changes in the activity of seasonal respiratory viruses, including RSV. After a period of suppression early in the pandemic, an interseasonal surge of RSV occurred in 2021. Viral activity was detected primarily in children and young adults after relaxation of public health measures, but without the usual proportional increases in infections and hospitalizations in older adults who were likely still adhering to stricter public health measures.

Rates of Medically-Attended RSV among US Adults: A Systematic Review and Meta-Analysis

Background

Adult respiratory syncytial virus (RSV) vaccines are in late stages of development. A comprehensive synthesis of adult RSV burden is needed to inform public health decision-making.

Methods

We performed a systematic review and meta-analysis of studies describing the incidence of medically-attended RSV (MA-RSV) among US adults. We also identified studies reporting nasopharyngeal (NP) or nasal swab RT-PCR results with paired serology (four-fold-rise) or sputum (RT-PCR) to calculate RSV detection ratios quantifying improved diagnostic yield after adding a second specimen type (ie, serology or sputum).

Results

We identified 14 studies with 15 unique MA-RSV incidence estimates, all based on NP or nasal swab RT-PCR testing alone. Pooled annual RSV-associated incidence per 100,000 adults ≥65 years of age was 178 (95%CI: 152‒204; n = 8 estimates) hospitalizations (4 prospective studies: 189; 4 model-based studies: 157), 133 (95%CI: 0‒319, n = 2) emergency department (ED) admissions, and 1519 (95%CI: 1109‒1929, n = 3) outpatient visits. Based on 6 studies, RSV detection was ∼1.5 times higher when adding paired serology or sputum. After adjustment for this increased yield, annual RSV-associated rates per 100,000 adults ≥65 years were 267 hospitalizations (UI: 228‒306) (prospective: 282; model-based: 236), 200 ED admissions (UI: 0‒478), and 2278 outpatient visits (UI: 1663‒2893). Persons <65 years with chronic medical conditions were 1.2−28 times more likely to be hospitalized for RSV depending on risk condition.

Conclusions

The true burden of RSV has been underestimated and is significant among older adults and individuals with chronic medical conditions. A highly effective adult RSV vaccine would have substantial public-health impact.

Evaluation of the ImmuView RSV Test for Rapid Detection of Respiratory Syncytial Virus in Adult Patients with Influenza-Like Symptoms

Rapid antigen tests may enhance the diagnostic yield of respiratory syncytial virus (RSV) infections, but studies have shown low sensitivity in adults. We evaluated the novel ImmuView RSV test in adult patients with influenza-like symptoms who were prospectively enrolled at three emergency departments in two Swedish hospitals during two influenza seasons, 2017 to 2018 and 2018 to 2019. The ImmuView RSV test was performed on nasopharyngeal swabs and results were compared to those of the BinaxNOW RSV test. In the first season, tests were performed on frozen samples, while unfrozen samples were used in the second season. For comparison, tests were also performed on selected samples from children. Of 333 included adult patients, the sensitivity of ImmuView and BinaxNOW was 27% for both tests and specificities were 98% and 100%, respectively. The interassay agreement was good (κ = 0.61). There was no significant difference in test performance between frozen and unfrozen samples. In samples from children, the sensitivities of ImmuView and BinaxNOW were 67% and 70%, respectively. In conclusion, the ImmuView RSV test showed low sensitivity and high specificity for identifying RSV in adult patients with influenza-like symptoms, comparable with the BinaxNOW RSV test. Rapid RSV testing is of limited value for diagnosing RSV infection in adults. IMPORTANCE By timely RSV diagnosis among patients with influenza-like symptoms, especially when influenza diagnostics turn negative, it is possible to prevent unnecessary antibiotic usage as well as reduce diagnostic testing, nosocomial transmission, and hospital stay. Previous rapid RSV tests have demonstrated poor sensitivity in adults, and we could demonstrate that the novel ImmuView RSV test similarly showed limited value for diagnosing RSV infection in adult patients. However, in contrast to many other studies, we investigated patient characteristics in cases with false-positive tests and we compared the performance between unfrozen and frozen samples. Thus, our results are important, as they generate new knowledge about rapid antigen tests.

Respiratory syncytial virus-associated deaths in the United States according to death certificate data, 2005 to 2016

BACKGROUND AND AIMS

In the United States, respiratory infections due to respiratory syncytial virus (RSV) cause an estimated 57 000 hospitalizations annually among children aged <5 years and 177 000 hospitalizations among adults aged ≥65 years. RSV-associated deaths are less well described. It will be important to establish a baseline of RSV-coded deaths prior to the introduction of vaccines, immunoprophylaxis products, and anti-viral therapies currently in development.

METHODS

US death certificate data for all ages from 2005 through 2016 were compiled through the National Center for Health Statistics. Deaths with International Classification of Diseases codes of J12.1 (RSV-pneumonia), J20.5 (RSV-bronchitis), or J21.0 (RSV-bronchiolitis) assigned as either the underlying cause of death or a contributing cause of death were considered "RSV-associated" for this analysis.

RESULTS

Among 30.5 million deaths, 1001 (.003%) were assigned an RSV-associated cause of death as follows: 697 (69.6%) RSV-pneumonia, 277 (27.7%) RSV-bronchiolitis, 17 (1.7%) RSV-bronchitis, and 10 (1.0%) with multiple RSV-associated causes. Most deaths were among children <5 (47.8%) and adults ≥50 (40.4%) years of age. Almost half (46.8%) had an RSV-associated cause as the primary underlying cause of death. The average annual number of RSV-associated deaths did not significantly change among those aged <5 and 5 to 49 years. However, RSV-pneumonia deaths among adults aged ≥50 years increased from 17.6 in 2005 to 2012 to 57.3 in 2013 to 2016 (P value <.0001).

CONCLUSIONS

From 2005 to 2016, the number of recorded RSV-associated deaths increased, primarily due to greater RSV-associated pneumonia deaths among older adults since 2013. The reasons for this increase are not clear but likely reflect increased testing for RSV among adults. The number of RSV-associated deaths according to death certificates compared with estimates derived from active, laboratory-confirmed surveillance and models using hospital administrative data suggests that counts from death certificates are a large underestimation, particularly among adults.

Cost determinants among adults hospitalized with respiratory syncytial virus in the United States, 2017-2019

BACKGROUND

Respiratory syncytial virus (RSV) infections are common in adults, but data describing the cost of RSV-associated hospitalization are lacking due to inconsistency in diagnostic coding and incomplete case ascertainment. We evaluated costs of RSV-associated hospitalization in adult patients with laboratory-confirmed, community-onset RSV.

METHODS

We included adults ≥ 18 years of age admitted to three hospital systems in New York during two RSV seasons who were RSV-positive by polymerase chain reaction (PCR) and had more than or equal to two acute respiratory infection symptoms or exacerbation of underlying cardiopulmonary disease. We abstracted costs from hospital finance systems or converted hospital charges to cost using cost-charge ratios. We converted cost into 2020 US dollars and extrapolated to the United States. We used a generalized linear model to determine predictors of hospitalization cost, stratified by admission to intensive care units (ICU).

RESULTS

Cost data were available for 79% (601/756) of eligible patients. The mean total cost of hospitalization was $8403 (CI₉₅ $7240-$9741). The highest costs were those attributed to ICU services $7885 (CI₉₅ $5877-$10,240), whereas the lowest were radiology $324 (CI₉₅ $275-$376). Other than longer length of stay, predictors of higher cost included having chronic liver disease (odds ratio [OR] 1.38 [CI₉₅ 1.05-1.80]) for patients without ICU admission and antibiotic use (OR 1.49 [CI₉₅ 1.10-2.03]) for patients with ICU admission. The annual US cost was estimated to be $1.2 (CI₉₅ 0.9-1.4) billion.

CONCLUSION

The economic burden of RSV hospitalization of adults ≥ 18 years of age in the United States is substantial. RSV vaccine programs may be useful in reducing this economic burden.

Respiratory viral infections in the elderly

With the global over 60-year-old population predicted to more than double over the next 35 years, caring for this aging population has become a major global healthcare challenge. In 2016 there were over 1 million deaths in >70 year olds due to lower respiratory tract infections; 13-31% of these have been reported to be caused by viruses. Since then, there has been a global COVID-19 pandemic, which has caused over 2.3 million deaths so far; increased age has been shown to be the biggest risk factor for morbidity and mortality. Thus, the burden of respiratory viral infections in the elderly is becoming an increasing unmet clinical need. Particular challenges are faced due to the interplay of a variety of factors including complex multimorbidities, decreased physiological reserve and an aging immune system. Moreover, their atypical presentation of symptoms may lead to delayed necessary care, prescription of additional drugs and prolonged hospital stay. This leads to morbidity and mortality and further nosocomial spread. Clinicians currently have limited access to sensitive detection methods. Furthermore, a lack of effective antiviral treatments means there is little incentive to diagnose and record specific non-COVID-19 viral infections. To meet this unmet clinical need, it is first essential to fully understand the burden of respiratory viruses in the elderly. Doing this through prospective screening research studies for all respiratory viruses will help guide preventative policies and clinical trials for emerging therapeutics. The implementation of multiplex point-of-care diagnostics as a mainstay in all healthcare settings will be essential to understand the burden of respiratory viruses, diagnose patients and monitor outbreaks. The further development of novel targeted vaccinations as well as anti-viral therapeutics and new ways to augment the aging immune system is now also essential.The reviews of this paper are available via the supplemental material section.

Clinical characteristics and disease burden of respiratory syncytial virus infection among hospitalized adults

The disease burden of respiratory syncytial virus (RSV) infection in the adult population has not been well characterized compared to children. Investigation of the clinical characteristics and disease burden of adult RSV infection would help to establish public health policy and a future vaccine strategy. We retrospectively collected medical records of hospitalized adult patients who were diagnosed with RSV infection from January 2012 to December 2015 from three tertiary hospitals. Baseline characteristics, clinical outcomes and economic charge during hospitalization were compared by age groups (19–49 years, 50–64 years, and ≥ 65 years) using Chi-square test. The odds of risk factors of RSV pneumonia were calculated using binary logistic regression. A total of 204 patients from three hospitals were enrolled. Patients who older than 65 years were 132 (64.7%). 118 (57.8%) patients had clinically confirmed pneumonia and 22 (10.8%) died in a hospital. The median medical cost of RSV pneumonia was 2,855.26 USD (interquartile range, 1,561.85–5,379.55) per each admission. Solid cancer (adjusted OR, 3.85; 95% CI, 1.65–9.02, p = 0.002) and hematologic malignancy (all patients had pneumonia) were shown to be risk factors for RSV pneumonia. RSV infection in South Korea seemed to have a significant burden among adults as pneumonia, care in the intensive care unit and mortality. Nationwide awareness and further effort to recognize the current burden, prepare specific treatment, and prevent adult RSV infection would be necessary.

Evaluation of Efficacy Endpoints for a Phase IIb Study of a Respiratory Syncytial Virus Vaccine in Older Adults Using Patient-Reported Outcomes With Laboratory Confirmation

OBJECTIVES

There are no approved vaccines for respiratory syncytial virus (RSV), and consensus on methods to assess RSV vaccine efficacy has not been established. In this study of an adjuvanted RSV vaccine, we evaluated an RSV disease endpoint using a patient-reported outcome instrument (the inFLUenza Patient-Reported Outcome instrument [FLU-PRO]) and molecular testing for virologic confirmation.

METHODS

In a randomized, blinded efficacy study (NCT02508194), 1900 adult participants aged ≥60 years who had any respiratory symptom lasting ≥24 hours recorded symptoms in a FLU-PRO-based workbook for 21 days, self-collected nasal swabs on illness days 2 to 4, and had a site-collected swab obtained on (approximately) day 4. The endpoint, acute RSV-associated respiratory illness (ARA-RI), required specific symptoms with virologic confirmation.

RESULTS

The FLU-PRO demonstrated reliability, ability to detect change, and validity and had high participant adherence and acceptable patient burden in the setting of an RSV prevention trial. The ARA-RI endpoint definition captured all 33 virologically confirmed RSV illnesses for which symptom data were provided, and in 32 of these, at least 1 lower respiratory symptom was reported. Sensitivity analysis with an endpoint requiring ≥2 lower respiratory symptoms captured greater symptom severity but fewer cases. Results of self- and site-collected swabs were highly correlated. Self-swabbing detected 9 additional cases that would have been missed by site swabbing only.

CONCLUSIONS

These results demonstrated the reliability and validity of the ARA-RI definition and of the FLU-PRO for use in RSV studies. Self-swabbing improved RSV detection.

Respiratory syncytial virus

Respiratory Syncytial Virus (RSV) is a leading cause of hospitalization and mortality associated with lower respiratory tract illness in infants and young children worldwide. The World Health Organization recognizes the need to develop and implement prevention strategies to reduce the impact of RSV in early life as a global health priority. RSV vaccination during pregnancy is a feasible strategy to achieve this goal. Vaccines for maternal immunization against RSV are in active development and could be implemented in the near future within existing maternal-child health platforms. In addition, infant protection may be achieved through either passive antibody administration or active immunization, depending on infant health status, given that options for these complementary interventions are being developed in parallel to vaccines for maternal immunization.

Immunobiological aspects of vaccines in pregnancy: Maternal perspective

Immunization during pregnancy is an efficient strategy to protect both the mother and the newborn infant against infectious pathogens. Pregnant women have an increased susceptibility to severe infections caused by some pathogens, but the mechanisms involved remain poorly understood. Pregnancy is associated with dynamic changes in maternal immune system that are critical for tolerance of the fetus. These changes could also play an important role in shaping maternal immune components that are transferred to the newborn infant following natural infection or vaccination to prevent infectious diseases in early life. As the momentum for maternal immunization is growing, there is a need to increase our understanding of the immunobiology of maternal immunization in order to better prevent infectious diseases in the pregnant women and the young infant.

What is the role of rapid molecular testing for seniors and other at-risk adults with respiratory syncytial virus infections?

Lower respiratory tract infections are a leading cause of hospitalization and viruses are important causal pathogens, especially in the elderly, immunocompromised patients and those with respiratory or cardiovascular comorbidities. Respiratory syncytial virus (RSV) is recognized as comprising a substantial burden of morbidity and mortality in older and at-risk adults, and the emergence of rapid point-of-care molecular testing has made it possible to confirm an RSV diagnosis accurately, in a clinically actionable timeframe. RSV patients have significantly higher healthcare resource use (including hospital stays and emergency room/urgent care visits) than non-RSV matched controls, especially if aged ≥65 years, a longer length of hospitalization than those with influenza, and associated costs nearly three times higher. We found no direct clinical outcome data specific to rapid molecular testing for RSV in adults and very little in children. There is very limited evidence that prompt diagnosis may reduce hospital length of stay but this and other outcome parameters need confirmation in larger, prospective clinical trials. Regarding reducing inappropriate antibiotic prescribing, the picture is mixed and testing alone is unlikely to change entrenched habits. There is little incentive for clinicians to order routine RSV tests in adults given the absence of a specific antiviral therapy. However, with numerous vaccine and antiviral candidates in clinical development, we believe it is good practice to plan and start establishing standardized testing protocols - perhaps as part of outcome studies. For especially vulnerable patients, e.g., immunocompromised and transplant patients, prompt accurate RSV diagnosis may prevent disease spread and save lives.

Microorganisms associated with respiratory syncytial virus pneumonia in the adult population

Respiratory syncytial virus (RSV) has been recognized as responsible for severe respiratory illness in adults, especially in the elderly. While pneumonia is commonly observed during RSV infection, the burden and epidemiology of bacterial superinfection is poorly understood. The aim of this study was to identify microorganisms associated with RSV-positive pneumonia in adults. A retrospective study was conducted during three consecutive winters (October to April 2013–2016) in the University Hospital of Lyon, France. During RSV circulation periods, a systematic RSV screening was performed by reverse-transcription PCR on all respiratory samples collected from adults. Records of RSV-positive patients were subsequently analyzed to identify radiologically confirmed pneumonia cases. Bacteria were identified by standard bacteriology cultures or urinary antigen screening and classified as potentially causative of pneumonia if quantification was above the specific threshold as defined by the European Manual of Clinical Microbiology. Overall, 14,792 adult respiratory samples were screened for RSV detection by PCR. In total, 292 had a positive RSV detection (2.0%) among which 89 presented with pneumonia including 27 bacterial superinfections (9.3%) with Streptococcus pneumonia, Haemophilus influenza, Staphylococcus aureus, Pseudomonas aeruginosa, and Moraxella catarrhalis. Most patients were elderly (55.6%) and patients with comorbidities (77.8%). A more severe outcome was observed for RSV-bacteria-associated pneumonia compared with RSV pneumonia: length of stay was significantly longer (16 days vs 10 days) and ICU hospitalization more frequent (66.7% vs 21.0%) (p < 0.05). In conclusion, we did not observe major differences in the epidemiology of bacterial superinfections in RSV-positive pneumonia compared to reports on post-influenza pneumonia.

Respiratory syncytial virus-associated illness in adults with advanced chronic obstructive pulmonary disease and/or congestive heart failure

BACKGROUND

Respiratory syncytial virus (RSV) is recognized as a serious pathogen in people with chronic cardiopulmonary conditions. Immunoprophylaxis might be considered for adults at high-risk for frequent and severe RSV infection. Thus, we studied the incidence of RSV-related medically attended acute respiratory illness (MARI) in adults with severe chronic obstructive pulmonary disease (COPD) and/or congestive heart failure (CHF).

METHODS

Subjects ≥50 years of age with Gold Class III/IV COPD and/or American Heart Association class III/IV CHF and exposure to children ≥once per month were recruited. Subjects were evaluated over 1.5 to 2.5 years for RSV-associated MARI, defined as polymerase chain reaction (PCR) and/or seroresponse.

RESULTS

Four hundred forty-five subjects were enrolled between October 2011 and May 2012. Overall, 99 RSV infections were documented by PCR or serology for a cumulative incidence of 22.2%. Of these, 42 (9.4%) subjects had protocol-specified RSV-MARI for an incidence of 4.68/100 patient-seasons. All-cause MARI was common (63.85/100 patient-seasons) with rhinovirus most commonly identified.

CONCLUSION

RSV infection was common in adults with severe COPD and/or advanced CHF. Given the severity of underlying cardiopulmonary diseases in the study population, most illnesses were surprisingly mild. Thus, active immunization rather than passive immunoprophylaxis with monoclonal antibodies may be a more cost-effective strategy.