This winter’s wave of norovirus infections has reached levels more than double last season’s peak, according to numbers released Monday by the Centers for Disease Control and Prevention, which tracks the notorious gastroenteritis.
Almost 28% of norovirus tests conducted during the week of the year-end and New Year holidays came back positive. highly contagious Viruses are the main cause of food poisoning, including: vomiting and diarrhea in the usa
That’s more than double the 13.52% of tests coming back positive at the peak of last season’s wave in March, according to data from public health labs across the country compiled by the CDC.
Typically, laboratories test stool samples from sick people for the presence of the virus and can make a diagnosis up to 10 days after symptoms appear. The virus can also be detected in other samples, such as contaminated food or drinks that can spread the virus.
Norovirus infection rates within the CDC system have reached levels at or above last season’s peaks in all regions of the country. The rate of positive norovirus tests appears to be worst in the Midwest, a group of states stretching from Kansas to Michigan.
Most people infected with norovirus recover without seeking medical attention, leaving a large proportion of cases unreported in the United States. Instead, health officials and experts use other measurements, such as test positivity rates, to track trends in the virus.
WastewaterSCAN’s sewage sampling data also suggests that norovirus infection rates in recent weeks have been highest not only in the Northeast, but also in the Midwest. The numbers released by private testing company BioFire Diagnostics also exceed previous seasonal peaks for norovirus.
Why will the number of norovirus infections increase so much in 2025?
Norovirus infection rates are always worse during the cold season, but in recent years, most trends tracking norovirus did not peak until March or April.
Different from previous seasons COVID-19 pandemicscrambled many of the bacteria’s normal seasonal patterns. During this time, norovirus outbreaks often reached peak levels as early as December and January.
Experts say the early and rapid increase in infections this year is due to new norovirus The virus, called GII.17 (P17), replaced an earlier strain that had dominated previous waves of the virus in the United States for a decade.
CDC officials told CBS News that the new strain has been identified across the country, including outbreaks on a number of cruise ships. Declining population immunity to GII.17 (P17) may explain this year’s unusual virus wave.
More than 7 out of 10 outbreaks this season have been linked to this new strain of norovirus, according to the latest statistics from the CDC.
