Trends in Rotavirus Laboratory Detections and Internet Search Volume Before and After Rotavirus Vaccine Introduction and in the Context of the Coronavirus Disease 2019 Pandemic—United States, 2000–2021

Abstract

Background Since rotavirus vaccines became available in the United States in 2006, there have been reductions in rotavirus hospitalizations, changes in seasonality, and the emergence of a biennial trend of rotavirus activity. Reductions in other pathogens have been associated with COVID-19 mitigation measures. We assessed ongoing rotavirus disease trends during the COVID-19 pandemic. Methods We report a 3-week moving average of the number of rotavirus tests, positive tests, and the percent positivity from laboratories reporting to the National Respiratory and Enteric Virus Surveillance System (NREVSS) from July 2000-June 2021. To complement NREVSS data, we analyzed Google internet search interest in “rotavirus” from July 2004 to June 2021. Results Declines in rotavirus activity following vaccine introduction and the biennial trend are evident through the 2018-2019 surveillance year. In 2019-2021, rotavirus test positivity was below the historic ranges during the months of typically high rotavirus activity and precipitous declines were noted in March 2020. Conclusions In the 15 years since rotavirus vaccine was introduced, the number of laboratory-detected rotavirus infections has been consistently lower than during the pre-vaccine era. During the COVID-19 pandemic, rotavirus activity was suppressed. There may be many rotavirus susceptible children during the 2021-2022 rotavirus season.

The changing pattern of common respiratory and enteric viruses among outpatient children in Shanghai, China: Two years of the COVID‐19 pandemic

“…In contrast to the Flu, the seasonality of RV was not changed in the post‐COVID‐19 period, with a high prevalence remaining in the winter months. The suppression of RV activity during the COVID‐19 pandemic has been reported in many other countries, such as Japan, 16 the United States, 30 Australia, 31 and Germany 32 . RV is transmitted predominantly through the fecal‐oral route and mainly by close person‐to‐person contact 29 .…”

Major Changes in Spatiotemporal Trends of US Rotavirus Laboratory Detections After Rotavirus Vaccine Introduction—2009–2021

“…Our findings are also consistent in showing low rotavirus disease activity during the first 2 years of the COVID-19 pandemic. 14 To understand the shift in earliest peak week eastward, we calculated a composite of birth rate and rotavirus vaccination coverage and found a concentration of states with both the average lowest coverage and highest birth rate also show earliest peak rotavirus activity. This moderate correlation was confirmed during all seasons except 2018-2019, when there were fewer contributing laboratories and less variation in peak week.…”

“…In an earlier NREVSS analysis, EIA and PCR tests from pediatric hospitals were found to have similar magnitude and generally similar peak week. 14 Second, the number of included laboratories decreased over time and the geographic sparseness of laboratories, particularly in the Mountain West region, may have obscured additional nuance. The declining number of laboratories contributing in NREVSS has been previously noted 1,14 and may be attributed to declines in testing caused by lower disease burden and changing testing practices from EIA to PCR.…”

“…Finally, our analysis ended with the 2018-2019 season. As rotavirus detections were depressed during the COVID-19 pandemic, 14 monitoring these trends after the pandemic will continue to be important. This analysis agrees with earlier studies that found changes in rotavirus seasonality and spatiotemporal trends in the United States since rotavirus vaccine introduction.…”

“…During each surveillance year, laboratories in the 48 contiguous states reporting ≥1 enzyme immunoassay (EIA) or polymerase chain reaction (PCR) test per week during ≥26 weeks, totaling ≥100 tests in a surveillance year, were eligible to be in that surveillance year’s spatiotemporal analysis. EIA and PCR tests were combined for this analysis, as they generally followed similar patterns in a previous NREVSS analysis 14 ; however, laboratories reporting PCR tests were limited to those from pediatric hospitals to reduce statistical noise due to multipathogen panel tests not ordered for suspected rotavirus. Although EIA is likely to be ordered for patients with suspected rotavirus, PCR tests might be more broadly used for acute gastroenteritis infections and so less specific to suspect rotavirus infections.…”