A sudden and unusually early rise in norovirus infections, often called the “winter vomiting disease”, has been reported across the United States, adding yet another health concern to a season already crowded with respiratory illnesses, as noted by Axios. Figures from the Centers for Disease Control and Prevention (CDC) show that positive norovirus tests have doubled over recent weeks, climbing from seven percent in August to 14 percent by mid-November.This spike has arrived sooner than expected and at a time when cases of COVID, whooping cough, and seasonal flu are also climbing.Winter Vomiting Disease: What Is The Norovirus?Norovirus leads to intense vomiting and diarrhea because it irritates the stomach and intestines, as described by the CDC. This has earned it the informal name “extreme vomiting disease.”It is the most frequent cause of vomiting and diarrhea in the country. Nearly 20 million people deal with norovirus each year, according to Scientific American. It is different from the common “stomach bug” or “stomach flu” and has no link to the influenza virus.Winter Vomiting Disease: Norovirus Symptoms To Watch ForSymptoms typically appear 12 to 48 hours after exposure and often include:DiarrheaVomitingNauseaStomach painDehydration (usually due to repeated vomiting and diarrhea)Less often, people may also experience fever, headaches, or body aches.Winter Vomiting Disease: Who Is At Risk For Norovirus?Norovirus outbreaks can affect anyone, but children and older adults face a higher chance of serious illness, the CDC notes. Since several strains of the virus exist, people may get sick more than once. Genetics may also influence how likely someone is to catch it.Winter Vomiting Disease: How Does Norovirus Spread?Health officials describe norovirus as extremely contagious. It spreads quickly through droplets, contaminated surfaces, or unsafe food.Norovirus is a human virus usually spread through the fecal-oral route,” explained Robyn Chatman, a Cincinnati physician, to the American Medical Association. This means the virus can transfer from contaminated hands to the mouth during routine activities. It can remain on surfaces for days or even weeks and moves rapidly in crowded places such as nursing homes, child care centers, and cruise ships, the AMA notes.Winter Vomiting Disease: Why Are Norovirus Cases Spreading In The US?A norovirus “outbreak,” as defined by the CDC, occurs when two or more similar illnesses stem from the same suspected or confirmed source. The CDC records about 2,500 such outbreaks each year.Between August 1 and November 13, 153 outbreaks were reported. By comparison, only 69 outbreaks had been recorded by the final week of November last year. In early December 2023, the U.S. logged 65 outbreaks, according to AP.Everyday Health reports that a new norovirus strain may be contributing to the current jump in cases. For many years, most infections were linked to the strain GII.4. Now another strain, GII.17, has become dominant, responsible for around 75 percent of outbreaks during the 2024–2025 season, up from about 10 percent during 2022–2023.What to Do if You Get Sick With Norovirus?There is no specific treatment for norovirus, as Cleveland Clinic explains. The infection needs to run its course. Staying well-hydrated, resting, and choosing mild, easy-to-digest foods can help ease symptoms. Seek medical care if you cannot keep fluids down or if your symptoms continue beyond three days.To prevent spreading the virus, the CDC advises avoiding food preparation or caring for others until at least 48 hours after symptoms stop.