Norovirus surge again in US, highest since 2012

Outbreaks of the highly contagious norovirus are on the rise in the United States, with officials reporting a spike in cases commonly referred to as the "winter vomiting bug" or "stomach flu." The Centers for Disease Control and Prevention (CDC) indicates that norovirus is at its highest recorded level for this time of year in over a decade.

During the first week of December, 91 suspected or confirmed outbreaks were reported, marking the highest level seen at this time since at least 2012. This significant uptick constitutes one of the largest case loads recorded at any point in the past 12 years.

It's important to note that this data currently only encompasses 15 states, meaning it may not paint a complete picture of norovirus's prevalence nationwide. However, the upward trend is evident, likely spurred by an increased number of states joining the monitoring program over the years.

The seasonal virus generally circulates more widely from November to April, with the US. recording approximately 2,500 outbreaks each year, usually peaking in February. Experts suggest that this year's outbreak may be more severe and occurring earlier than in previous years, potentially due to increased social interactions "for the first time in several years."

Additionally, many countries are experiencing a rise in various seasonal illnesses as people come together more frequently during the holidays than they did during the pandemic. Besides norovirus, conditions such as the flu and respiratory syncytial virus (RSV) are also on the rise. Although COVID-19 no longer poses the same level of threat, it remains prevalent. Health officials are particularly concerned about relatively high levels of whooping cough, which can be dangerous for infants.

In response to the increasing incidence of seasonal viruses, numerous public health authorities, including those in the UK, have been urging the public to get vaccinated and maintain hygiene practices to mitigate the spread of contagious diseases. Officials have described the situation as a "quad-demic," involving flu, COVID-19, RSV, and norovirus, with 95% of England's hospital beds occupied by early December.

Understanding Norovirus

Norovirus is the leading cause of vomiting, diarrhea, and foodborne illness in the US Despite its common moniker as "stomach flu," it is not related to influenza. The virus spreads through tiny particles of infected fecal matter that can enter the mouth, meaning individuals can contract it by consuming contaminated food or beverages or touching their mouths after contacting contaminated surfaces, such as doorknobs. Caregivers looking after infected individuals are also at high risk of transmission.

Symptoms of norovirus typically include vomiting, nausea, diarrhea, and stomach pain, but may also lead to fever, headaches, and body aches. While the illness can be quite distressing, most individuals recover within approximately three days. Staying hydrated is crucial, as both vomiting and diarrhea can lead to dehydration. If severe dehydration is suspected, medical assistance should be sought promptly.

Protecting yourself against Norovirus

Vigilant hand hygiene is the most effective means of protection against norovirus. Regularly wash your hands with soap and warm water for at least 20 seconds, especially after using the bathroom, changing diapers, shaking hands, or caring for someone with the virus.

It is advised not to share food or drinks with those infected and to wash any potentially contaminated fabrics in hot water. Thoroughly washing fruits and vegetables, as well as cooking seafood adequately, can help prevent the virus from spreading through food sources.

If you contract norovirus, protect others by remaining at home for at least two days after your symptoms have ceased. The virus can be transmitted for as long as two weeks post-symptom resolution, making ongoing handwashing essential.

Norovirus vaccination status

Currently, there is no vaccine available for norovirus. However, researchers at Moderna have recently commenced trials for a candidate vaccine that may provide protection in the future. Vaccinations remain the best preventative measure against a plethora of seasonal illnesses, including whooping cough and measles, which are also seeing increased rates in the US.

Annual flu vaccines are offered every fall and are recommended for nearly all individuals over the age of six months, particularly those at greater risk of severe disease. Hospitalizations due to flu range between 140,000 and 710,000 each year, resulting in an estimated 12,000 to 51,000 deaths.

RSV vaccines are available for older adults and pregnant individuals, who can pass immunity to their vulnerable infants. Similarly, COVID-19 vaccines are recommended annually for anyone aged six months or older, especially for older adults and individuals at higher risk of severe illness or those unvaccinated.