Amount of Low-Income Young Children and Older Adult Hospitalizations Due to RSV Is Substantially Underestimated

Recorded diagnoses for respiratory syncytial virus (RSV) likely only accounts for a small amount of the burden of hospitalizations and disparities in care among different populations and socio-economic groups, according to research published in Pneumonia.

A statistical analysis study at the Department of Epidemiology of Microbial Diseases and the Public Health Modeling Unit, Yale School of Public Health at Yale University aimed to evaluated the annual incidence of RSV-associated hospitalizations across localities to understand the under-recorded ratio in different subpopulations.

“There are a number of potential causes for this disparity, including factors that might influence risk of viral infection, such as family size and the number of contacts; exposure to tobacco smoke and other pollutants; high prevalence of underlying respiratory diseases like asthma and chronic lung disease from prematurity; and shorter duration of breastfeeding,” wrote the researchers.

A person’s monthly age-, zip code–, and cause-specific hospitalizations in New York, New Jersey, and Washington were obtained from the US State Inpatient Databases (2005-2014). Using regression models, the researchers estimated the incidence of attributable RSV respiratory incidences regarding age and socioeconomic status (SES). Zip codes were divided into 3 SES groups based on income. Additionally, monthly data was collected on the number of hospitalizations recorded due to RSV using International Classification of Diseases, Ninth Revision, Clinical Modification codes.

Form July 2005 to June 2014, there was a total of 9,418,390 hospitalizations for respiratory illnesses containing age and zip code information. Of these, 66,679 hospitalizations were recorded for RSV infections among children aged 2 years or younger.

The estimated number of RSV hospitalizations among children in the lowest SES group was almost double that of children in the highest SES group. For older adults aged 65 and older, the researchers estimated that less than 5% of RSV hospitalizations were captured accurately in hospital records.

The results produced in this study found the estimated annual incidence of respiratory hospitalizations due to RSV was highest among infants, less than 1 year old with a low socio-economic status (2800, 95% CI [2600-2900] per 100,000 person-years). The other highest age groups for RSV hospitalizations were children 1 to 2 years of age and older adults aged 85 years or older.

There were several limitations to this study:

• There may be time differences in infection among age groups
• The number of RSV hospitalizations may be overestimated by not including respiratory infections other than influenza and RSV
• The estimates could not separate RSV coinfection from infection caused by RSV alone
• Estimates relied on the validity of RSV hospitalization estimates by the hospitals
• The analysis stopped after 2014 when coding shifted from ICD9 to ICD10.

The researchers of this study suggest that more research be done, especially regarding the incidence of hospitalizations for RSV infections in older adults, which they believe might help better define the burden of RSV. Additionally, the researchers suggest that vaccines for RSV might also prove to be of substantial benefit to young children and older adults.

“Children and families residing in low-SES areas had the highest incidence of RSV-associated hospitalizations for respiratory illnesses. The incidence of hospitalizations for RSV infections among older adults is greatly under-recorded,” the researchers concluded.

References

Zheng Z, Warren JL, Shapiro ED, Pitzer VE, Weinberger DM. Estimated incidence of respiratory hospitalizations attributable to RSV infections across age and socioeconomic groups. Pneumonia (Nathan). 2022;14(1):6. Published October 25, 2022. doi:10.1186/s41479-022-00098-x