A spike in outbreaks of a highly contagious stomach bug have been reported in 14 states including Virginia, according to data released from the Centers for Disease Control and Prevention, or CDC.
In its monthly data report, 91 outbreaks of norovirus were reported for the first week of December. The number nearly tripled since Nov. 21, when only 32 outbreaks were reported in the 14 states included in the data.
A norovirus outbreak is defined as an occurrence of two or more similar illnesses resulting from a common exposure.
Those who are infected with norovirus have a sudden onset of nausea, vomiting, diarrhea and stomach cramps.
Outbreaks are most common in long-term care facilities, hospitals, restaurants, schools, day care centers and cruise ships, according to the Virginia Department of Health. Good hand washing is the key to prevention as the virus is most often passed on by infected food handlers.
Virginia does not report individual cases of norovirus, so individual case counts are not available, according to Kelsey Holloman, the VDH epidemiologist from the division of surveillance and investigation.
Virginia does produce a weekly GI report that tracks viruses having to do with the gastrointestinal tract. Specifically, it tracks both norovirus-like outbreaks and emergency department and urgent care treatment for GI conditions.
On Dec. 1, the GI report showed only four potential outbreaks in the Commonwealth. Thirteen outbreaks were reported on Dec. 8; and 14 outbreaks were reported on Dec. 15, showing a similar increase to the overall data set of 14 states collected in the CDC information.
The CDC data lags behind data provided today from the Virginia Department of Health. The data in the CDC report is collected through the National Outbreak Reporting System, or NORS. The CDC data table is updated online monthly.
Virginia has also recorded an increase compared to a similar time last year. In 2023, on Dec. 3, there were six outbreaks reported. The number climbed to 10 cases in 2023 before a decline in numbers. A spike of outbreaks returned in February of this year, with cases in Virginia climbing to 14.
Norovirus outbreaks tend to be higher in Virginia in winter months, typically from December through March each year.
The norovirus infection usually begins 10 to 50 hours after exposure, and the illness is usually short, lasting one to three days.
People infected with the norovirus can remain contagious for up to a month after they have recovered.
The 14 states included in the CDC report include Alabama, Colorado, Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, North Carolina, Ohio, Oregon, South Carolina, Tennessee, Virginia and Wisconsin.
Each year, there are approximately 2,500 reported norovirus outbreaks in the United States.