Nevada health officials investigate norovirus outbreak

Health officials from Washoe County, Nevada, are investigating a recent norovirus outbreak that infected 768 students, staff and faculty at 17 schools and three day care centers, according to the county’s health district.

“We have seen outbreaks through school systems in previous years, so this is unfortunately not all that uncommon,” Randall Todd, DrPH, director of Epidemiology and Public Health Preparedness for the Washoe County Health District, told Infectious Disease News. “[Norovirus] can survive in the environment for a period of time, so it’s not unusual to see it spread very rapidly.”

Randall Todd

The first cases were reported around mid-September, Todd said. The county’s epidemiology and public health preparedness department continues to work with schools on a three-prong approach that involves extensive disinfection, excluding ill children from school and pre-emptive handwashing with warm, soapy water.

The county’s health district recommends that school staff conduct intense cleaning around a 25-foot radius where there has been a public vomiting incident, including “high-touch” surfaces, according to Todd. Those who develop infection should not return to school until 3 days post-symptoms.

“That’s very difficult because many parents work, so having a child not in school is a hardship for them, especially when the child feels better,” Todd said. “They have a hard time understanding that the child may still be shedding virus. We know there is still virus shedding after 72 hours, but we’re hoping the virus shed, at that point, is less viable.”

The facilities involved in the outbreak reported following health district guidelines, according to a press release. However, a driver of the outbreak may be associated with children who develop symptoms during the weekend and return to school on Monday, Todd said.

“The school would never know there was a case, so [the children] were never officially excluded from school,” he said. “It’s frustrating, not only for public health [officials], but for the school system and probably for the parents as well. This is a difficult situation, but we try to work aggressively with the school district and the parents to try to prevent it.”

During the investigation, health officials will continue to work with the Washoe County School District and the day care facilities involved to mitigate the situation, according to the release.

The CDC estimates that norovirus causes 19 million to 21 million illnesses, 56,000 to 71,000 hospitalizations and 570 to 800 deaths each year. Many people develop norovirus in cooler months, particularly from November to April, and can develop the infection five times during their lifetime. – by Stephanie Viguers

Disclosure: Todd reports no relevant financial disclosures.