Norovirus Outbreaks Take California Schools by Storm

The school year may be ending soon, but as summer breaks nears thousands of students in California are suffering from outbreaks of norovirus.

The highly-contagious norovirus causes about 20 million cases of acute gastroenteritis in the United States each year, resulting in as many as 71,000 hospitalizations and up to 800 deaths annually. The virus can be spread through contact with infected individuals, contaminated food or water, or contaminated surfaces. Norovirus infection is marked by inflammation in the stomach or intestines. Associated symptoms include stomach pain, nausea, vomiting, diarrhea, fever, and headache. While norovirus illness typically subsides within 3 days, it can result in severe dehydration requiring hospitalization and treatment with intravenous fluid. Young children and the elderly are most likely to experience severe illness from the virus. While norovirus outbreaks occur most often in the winter, they can happen throughout the year.

Since May 1, norovirus outbreaks have been occurring in schools across California, including in Yolo County where 3,374 area students and staff members from at least 32 area schools have become infected. In response to the outbreak in the Sacramento area, Yolo County, two schools with a high number of illnesses closed on Friday, May 26, extending the Memorial Day weekend to limit students’ exposure to infected classmates. “While we have enhanced our cleaning efforts and worked to limit student interactions on campus, we need to take an even more aggressive approach at these two schools to end the outbreak,” said Tom Pritchard, interim superintendent at Yolo County’s Woodland Joint Unified School District, in a recent statement. “Having students and staff away from school for four days will greatly reduce [the rate of] transmission of the virus and allow for additional deep cleaning at both sites.”

The recent outbreaks come following norovirus outbreaks earlier this spring in Santa Monica and East Bay area schools, in which hundreds of students as well as many of their family members became ill. The current series of outbreaks in California has also affected at least 13 schools in the Bay Area’s Santa Clara County, leaving hundreds of students sick and causing schools to cancel after-school programs and extracurricular activities. The California Department of Public Health (CDPH) is urging any students experiencing norovirus symptoms to stay home while sick and to avoid contact with others for two days after their symptoms subside. “Norovirus outbreaks usually have an annual peak like we are seeing now. They can be particularly large and disruptive in schools, affecting both students and teachers,” said CDPH director Karen Smith, MD, MPH, in a recent press release. “Norovirus is very infectious and can spread rapidly wherever people congregate and share food and bathroom facilities. Fortunately, most people with norovirus infection will recover quickly, usually in one to three days.”

To prevent further spread of norovirus, the CDPH recommends properly washing hands and handling food safely, along with disinfecting any surfaces and objects that have come in contact with vomit or diarrhea with a bleach solution. Contaminated clothes or linens should be washed in a washing machine with detergent. Wear gloves and wash hands carefully after any contact with contaminated objects.