Norovirus cases increase in Los Angeles County: Health officials

Health officials in Los Angeles County are reporting a rise in norovirus cases. Data from the Los Angeles County Department of Public Health, gathered from wastewater samples, indicates a significant increase in the virus's presence.

Wastewater analysis, which involves collecting water from sewage systems to check for pathogens, revealed a 154% increase in norovirus detection within Los Angeles and over a 250% increase countywide during the 21-day period ending December 11, according to KABC, ABC's Los Angeles affiliate.

The health department, in a statement reported by KABC, stated that this increase is in line with typical trends. They anticipate norovirus activity to increase between November and April, as outbreaks are more frequent during cooler months.

This trend in Los Angeles mirrors national patterns. Data from the Centers for Disease Control and Prevention (CDC) showed that in mid-November, almost 13% of tests for norovirus were positive, compared to about 7% three months prior. More recently, however, the CDC's data indicates a possible decline in national cases, with 9.37% of tests returning positive for the week ending December 6.

Norovirus is a highly contagious virus and the most common cause of viral gastroenteritis, an inflammation of the gastrointestinal tract lining.

Often called the "stomach bug" or "stomach flu," it is important to note that norovirus is not related to the influenza virus.

According to the CDC, norovirus is the leading cause of foodborne illness in the United States, responsible for 58% of all foodborne illnesses each year and approximately 25,000 outbreaks annually.

Common symptoms include nausea, vomiting, stomach pain, and non-bloody diarrhea. Infected individuals may also experience fever, headaches, and body aches.

Symptoms typically appear 12 to 48 hours after infection and usually resolve within one to three days in healthy adults, according to the CDC.

Health experts recommend washing hands thoroughly with warm water and soap for at least 20 seconds as the best way to prevent norovirus infection. Hand sanitizer is not as effective against this virus.

The CDC advises washing hands after using the toilet or changing diapers, and before eating, preparing, or handling food.

The Los Angeles health department, as reported by KABC, also recommends carefully washing fruits and vegetables and thoroughly cooking shellfish, as freezing will not kill the virus.

If infected with norovirus, individuals should avoid preparing food for others for three days following recovery, according to the health department.