The United States is experiencing a significant uptick in norovirus cases, commonly known as a stomach bug, this winter, according to recent data from the Centers for Disease Control and Prevention (CDC). This surge is marked by a notable increase in reported outbreaks compared to previous years.
During the week of December 5th, the CDC reported 91 norovirus outbreaks, a jump from 69 outbreaks in the final week of November. These figures exceed the maximum of 65 outbreaks reported during the same period in previous years, indicating a substantial rise in infections.
Norovirus infections are characterized by sudden onset of vomiting and diarrhea. Outbreaks frequently occur in close-quarters settings like cruise ships, nursing homes, schools, and correctional facilities. It is the leading cause of foodborne illness in the U.S., accounting for 58% of such infections annually.
These highly contagious viruses spread easily, with as few as ten viral particles capable of causing illness. The CDC notes around 2,500 norovirus outbreaks occur in the U.S. each year, with a seasonal peak from November to April. Common symptoms include nausea, stomach pain, body aches, headaches, and fever in addition to vomiting and diarrhea.
Transmission often occurs directly through sharing food or utensils, or indirectly through contaminated food, water, and surfaces. The illness typically develops within 12 to 48 hours following exposure, with most individuals recovering fully within one to three days. However, the CDC reports the virus leads to approximately 900 deaths and 109,000 hospitalizations annually, mostly among older adults. It also results in 465,000 emergency department visits annually, predominantly involving young children.
While people of all ages can be affected, young children, older adults, and individuals with weakened immune systems are at higher risk. The primary concern is dehydration caused by vomiting and diarrhea.
There is no specific medication to treat norovirus. Rehydration is crucial, and is typically achieved by drinking water and other liquids, avoiding caffeine and alcohol. Individuals experiencing severe dehydration, indicated by decreased urination, dry mouth and throat, or dizziness, should seek immediate medical attention. Children may show signs of dehydration by being unusually sleepy or fussy, and crying with few or no tears.
Preventive measures are essential, with rigorous handwashing being the most effective defense. Washing hands for at least 20 seconds with soap and warm water, particularly before meals, is strongly recommended. Furthermore, regular disinfection of surfaces is advised to help curb the spread of the virus.
