Incidence of Respiratory Syncytial Virus Infection Among Hospitalized Adults, 2017-2020.

BACKGROUND: Respiratory syncytial virus (RSV) causes acute respiratory illness (ARI) and triggers exacerbations of cardiopulmonary disease. Estimates of incidence in hospitalized adults range widely, with few data on incidence in adults with comorbidities that increase the risk of severity. We conducted a prospective, population-based, surveillance study to estimate incidence of RSV hospitalization among adults overall and those with specific comorbidities. METHODS: Hospitalized adults aged ≥18 years residing in the surveillance area with ≥2 ARI symptoms or exacerbation of underlying cardiopulmonary disease were screened during the 2017-2018, 2018-2019, and 2019-2020 RSV seasons in 3 hospitals in Rochester, New York and New York City. Respiratory specimens were tested for RSV using polymerase chain reaction assays. RSV incidence per 100 000 was adjusted by market share. RESULTS: Active and passive surveillance identified 1099 adults hospitalized with RSV. Annual incidence during 3 seasons ranged from 44.2 to 58.9/100 000. Age-group-specific incidence ranged from 7.7 to 11.9/100 000, 33.5 to 57.5/100 000, and 136.9 to 255.6/100 000 in patients ages 18-49, 50-64, and ≥65 years, respectively. Incidence rates in patients with chronic obstructive pulmonary disease, coronary artery disease, and congestive heart failure were 3-13, 4-7, and 4-33 times, respectively, the incidence in patients without these conditions. CONCLUSIONS: We found a high burden of RSV hospitalization in this large prospective study. Notable was the high incidence among older patients and those with cardiac conditions. These data confirm the need for effective vaccines to prevent RSV infection in older and vulnerable 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.

Severe Clinical Outcomes Among Adults Hospitalized With Respiratory Syncytial Virus Infections, New York City, 2017-2019.

OBJECTIVES: Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in older adults. We assessed severe clinical outcomes among hospitalized adults that were associated with RSV infections. METHODS: We performed a nested retrospective study in 3 New York City hospitals during 2 respiratory viral seasons, October 2017-April 2018 and October 2018-April 2019, to determine the proportion of patients with laboratory-confirmed RSV infection who experienced severe outcomes defined as intensive care unit (ICU) admission, mechanical ventilation, and/or death. We assessed factors associated with these severe outcomes and explored the effect of RSV-associated hospitalizations on changes in the living situations of surviving patients. RESULTS: Of the 403 patients studied (median age, 69 years), 119 (29.5%) were aged ≥80. Severe outcomes occurred in 19.1% of patients, including ICU admissions (16.4%), mechanical ventilation (12.4%), and/or death (6.7%). Patients admitted from residential living facilities had a 4.43 times higher likelihood of severe RSV infection compared with patients who were living in the community with or without assistance from family or home health aides. At discharge, 56 (15.1%) patients required a higher level of care than at admission. CONCLUSIONS: RSV infection was associated with severe outcomes in adults. Living in a residential facility at admission was a risk factor for severe outcomes and could be a proxy for frailty rather than an independent risk factor. Our data support the development of prevention strategies for RSV infection in older populations, especially older adults living in residential living facilities.

Comparative incidence and burden of respiratory viruses associated with hospitalization in adults in New York City.

BACKGROUND: Although the burden of influenza is well characterized, the burden of community-onset non-influenza respiratory viruses has not been systematically assessed. Understanding the severity and seasonality of non-influenza viruses, including human coronaviruses, will provide a better understanding of the overall disease burden from respiratory viruses that could better inform resource utilization for hospitals and highlight the value of preventative strategies, including vaccines. METHODS: From October 2017 to September 2019, a retrospective study was performed in a pre-defined catchment area to estimate the population-based incidence of community-onset respiratory viruses associated with hospitalization. Included patients were ≥18 years old, resided in New York City, were hospitalized for ≥24 hours, and had a respiratory virus detected within 3 calendar-days of admission. Disease burden was measured by hospital length of stay (LOS), intensive care unit (ICU) admissions, and in-hospital mortality and compared among those with laboratory-confirmed influenza versus those with laboratory-confirmed non-influenza viruses (human coronaviruses, parainfluenza viruses, respiratory syncytial virus, human metapneumovirus, and adenovirus). RESULTS: During the study period, 4232 eligible patients were identified of whom 50.9% were ≥65 years of age. For each virus, the population-based incidence was highest for those ≥80 years of age. When compared to those with influenza viruses detected, those with non-influenza respiratory viruses detected (combined) had higher population-based incidence, significantly more ICU admissions, and higher in-house mortality. CONCLUSIONS: The burden of non-influenza respiratory viruses for hospitalized adults is substantial. Prevention and treatment strategies are needed for non-influenza respiratory viruses, particularly for older adults.