Norovirus Symptoms: Stomach Bug Cases On Rise In US? What Is the Incubation Period?

The US Centers for Disease Control and Prevention (CDC) has reported that the stomach bug known as "norovirus" is spreading rapidly across the northeastern region of the US, affecting the region more severely than other parts of the country. Recent data shows a surge in norovirus cases in various regions of the US.

In the northeastern region, the three-week average of positive norovirus tests reached 13.9% in the recent week and has remained at a 10% positive rate since mid-December 2023. Similar increases in positive tests have been reported in other regions: the Southern US saw 9.5% positive tests, the Midwestern US saw 10%, and the Western US saw about 12%.

Norovirus is the leading cause of vomiting, diarrhea, and foodborne illness in the United States, according to the CDC. The virus can infect people of all ages and spreads very easily and quickly.

The CDC also noted that people can be infected with norovirus multiple times in their lifetime due to the existence of many different types of the virus. While individuals may develop immunity against specific types, the duration of this protection is unknown.

Norovirus outbreaks are common in late fall, winter, and early spring. Symptoms include fever, headache, dehydration, and body aches. Infected people usually experience acute onset of vomiting and non-bloody diarrhea. The incubation period is 12-48 hours. Other symptoms include abdominal cramps, nausea, and sometimes a low-grade fever. Illness is generally self-limited, and most patients fully recover in 1-3 days.

Norovirus treatment

To prevent the spread of norovirus, the CDC recommends washing hands thoroughly with soap and water, cleaning and disinfecting surfaces with bleach, and washing laundry with hot water.

Each year, between November and April, the US records 19 to 21 million illnesses caused by norovirus, resulting in approximately 109,000 hospitalizations and 900 deaths, with older adults being most commonly affected.