A highly contagious virus that causes vomiting and diarrhea is likely affecting some people in Los Angeles County.
Concentrations of norovirus, sometimes referred to as the “winter vomiting disease,” detected in wastewater is increasing in the county, the Los Angeles County Department of Public Health told the USA TODAY Network in an email on Tuesday, Dec. 16. Officials use wastewater to monitor the presence of infectious diseases within a community, like norovirus or the virus that causes COVID-19.
The county public health department said that wastewater detection of norovirus increased 154% in Los Angeles for three weeks ending on Dec. 11. In Los Angeles County, wastewater detection of norovirus increased by over 250% for the same period.
Norovirus wastewater detection levels in the county are higher than levels reported for the same period last year, according to the public health department.
“Increasing norovirus concentrations in Los Angeles County indicate that the virus is likely spreading in Los Angeles County,” the public health department said.
Norovirus: How does it spread?
Norovirus spreads easily through direct contact with someone who is infected, eating contaminated food, drinking contaminated water, or touching a contaminated surface and then touching your mouth. That’s why county health officials encourage frequent handwashing, especially before eating or preparing food or using the bathroom, and washing fruits and vegetables “thoroughly.”
While you can get sick with norovirus throughout the year, people fall ill with it most commonly between November and April, according to the California Department of Public Health. Last year, however, the “norovirus season” began earlier than in previous seasons, according to a research letter from the Centers for Disease Control and Prevention. In the U.S., the norovirus season typically starts in early December, but “the onset of the season was in early October 2024,” according to the research letter.
How long does norovirus last?
Symptoms usually last one to three days, according to the California Department of Public Health. Symptoms could onset as early as 12 hours after exposure, according to the county public health department.
How long is norovirus contagious?
According to studies, you may still be contagious for two weeks or longer even after feeling better, the CDC said.
Norovirus symptoms: Here’s what to look out for
Norovirus commonly causes vomiting, diarrhea, nausea, and stomach cramps. But other symptoms of it can include fever, headache, and body aches.
Paris Barraza is a reporter covering Los Angeles and Southern California for the USA TODAY Network. Reach her at pbarraza@usatodayco.com.
This article originally appeared on USA TODAY: Norovirus ‘likely spreading’ in LA County. It’s very contagious
