In the 15 years following the release of the first rotavirus vaccination in the United States in 2006, annual rotavirus activity in the country followed a clear spatiotemporal pattern, with the highest levels observed in the Southwest and lowest in the Northeast. The study predicted changes in the geographic distribution of rotavirus detections made in laboratories from 2009 to 2021. For a particular surveillance year (July–June), laboratories reporting to the National Respiratory and Enteric Virus Surveillance System had to report more than equal 1 rotavirus test each week for at least 26 weeks, for a total of at least more than equal to 100 tests per year, to be included. The National season is defined as the period with a 3-week moving average of more than 10% rotavirus positivity lasting 2 consecutive weeks. The peak week for each laboratory was the week with the highest 7-week moving average of the number of rotavirus positive tests. In order to perform Kriging spatial interpolation, researchers used a spherical variogram model and fed it the peak week as a continuous variable as well as the geographic coordinates of each laboratory. Investigators constructed a state-level bivariate choropleth map using tertiles of average birth rates from 2010-2019 and rotavirus vaccine coverage. The geospatial study comprised years of surveillance that showed more than 10% rotavirus positivity for more than equal to 2 weeks in 2010-2011, 2012-2013, 2014-2015, 2016-2017, and 2018-2019, continuing the established biannual trend. When comparing post-vaccine seasons to those before, the geographic analysis found that the earliest peak week occurred in Oklahoma, Arkansas, and the western Gulf coast. The greatest birth rates and lowest rotavirus vaccination coverage were seen in these states, which may indicate that a greater number of youngsters become susceptible to the virus each year. One of the most effective methods of decreasing the prevalence of rotavirus is increasing the number of people who receive the necessary vaccinations.

Source: journals.lww.com/pidj/Fulltext/2022/09000/Major_Changes_in_Spatiotemporal_Trends_of_US.22.aspx