In overburdened health care systems, such as during pandemics, their respiratory syncytial virus (RSV) measurements and long-term temporal and spatial trends can be estimated using hospitalization data, according to a published study. Frontiers in Pediatrics.
RSV often causes mild respiratory infections, but can be more severe in children younger than 2 years old. RSV infections are best predicted by season, most frequently in late fall, winter, and early spring. However, the COVID-19 pandemic has changed the seasonality of RSV. The aim of this study was how the COVID-19 pandemic has affected pediatric RSV infections at the state and county level in Texas.
Texas hospital discharge records and the Texas Public Use Data File (PUDF) from 2006 Quarter 1 to 2021 Quarter 4 were used for this study. Variables used were discharge diagnosis, length of stay, patient age, patient status at end of service, and patient county. All discharge diagnoses were included in the dataset, and analysis focused on RSV-related hospitalizations among children aged 5 years and younger.
Quarterly hospitalization rates for children 4 years of age and younger were calculated from monthly RSV-related hospitalization rates reported to the RSV Hospitalization Surveillance Network (RSV-NET) from 2018 to 2022. Children were divided into 3 groups based on the PUDF dataset: 1 to 28 days of age, 29 to 365 days of age, and 1 to 4 years of age.
Of the 158,920 RSV-associated hospitalizations from 2006 to 2021 that were included in this study, the majority of hospitalizations occurred in children younger than 5 years (89%). Breaking it down further, hospitalization rates were highest among infants aged 29 to 365 days (65%) and lowest among infants aged 1 to 28 days (8%) from 2006 to 2019. However, this changed in 2021, when the highest percentages of hospitalizations were seen for patients aged 1 to 28 days (57%) and 1 to 4 years (40%).
Seasonal patterns in hospitalizations were consistent between 2006 and 2019. The highest number of cases were found in 2010, 2011 and 2019 and all years from 2006 to 2019 had a general decreasing trend in the first Q1 and increased in all other quarters.
When compared with a linear regression model predicting hospitalizations for RSV in 2020 and 2021, minus the impact of COVID-19, the 2020 season showed fewer hospitalizations and a sharp peak in 2021 Q3. The outbreak peak was 1.5 times higher than expected and occurred almost a year later than expected, in 2021 Q3 rather than 2020 Q4. The number of cases in 2021 Q2 (n = 1223) is also 2.6 times higher than a normal season and 5 times higher with an assumed seasonal variation. Hospitalization rates over time saw a decreasing trend in Q1 while all other quarters showed an increasing trend.
RSV-associated hospitalizations at the state and county levels from 2018 to 2021 were 1.9 and 9.5 times higher than those reported in the RSV-NET data. The disparity was greater in 2020 and 2021, with average county-level rates 43 times that of RSV-NET and state hospitalization rates 5 times those reported in RSV-NET.
Duration follows the seasonal trend from 2006 to 2019, with longer periods in Q2 and Q3. However, it was affected during the pandemic, as length of stay was 6.5 times higher than expected in Q4 2020 (29.3 vs. 4.5 days). The rate of expired conditions in 2020 is 2.28 times higher (0.39%) than the 2006 to 2019 average (0.17%).
Texas had the highest hospitalization rate in the second quarter of 2020 in a rural county, and 3 urban counties reported cases during the epidemic. RSV re-emergence was observed to follow the common onset but at a higher and more widely distributed rate. No cases of RSV were found in rural areas of the southwest border during the COVID-19 pandemic but were reported prior to 2020.
Potential limitations of the findings of this study include the researchers who used International Classification of Diseases, Ninth Revision, And 10th Amendment, Clinical Modification RSV diagnosis codes, which may misrepresent hospital burden; This study did not examine co-infections and risk factors for RSV hospitalization; And lack of viral exposure has not been tested as a cause of the atypical peak of RSV in 2021.
The researchers concluded that monitoring RSV-associated hospitalizations is an important way to assess the burden of RSV infection in pediatric hospitals. Observing how the Covid-19 pandemic has changed RSV hospitalizations illustrates the role played by seasonality and increased hospitalizations for RSV.
reference
Uwak I, Johnson N, Mustapha T, et al. Quantifying changes in respiratory syncytial virus-associated hospitalizations among Texas children during the Covid-19 pandemic using records from 2006 to 2021. Front Pediatrics. Published online March 13, 2023. Doi:10.3389/fped.2023.1124316