In early September, at least 104 students and six staff members in a North Carolina school district were sent home with “virus type symptoms” of a mystery illness. Officials didn’t know what was behind the outbreak, and they’ve reached out to the local health department and Centers for Disease Control and Prevention for help.

While the idea of an unknown illness causing an outbreak is slightly terrifying, officials comment that they are fairly common. And although the cause of the outbreak is not identified immediately, those officials say that once an investigation unfurls, the cause is usually determined.

According to reports, the problem in determining the cause of the illness right away is that there are many reasons people could have developed symptoms such as vomiting, diarrhea, and fever. Those include norovirus (aka the “cruise ship virus”), enterovirus, or a food-borne illness that could have infected the school district’s food supply. As a result, an outbreak can be due to a “mystery” illness for days or even weeks until experts are able to accurately determine its cause.

For facilities that find themselves in the midst of an outbreak, officials encourage ramping up proper hand hygiene. Washing hands with soap and water can work wonders. Adding alcohol-based sanitizers can also be effective against some viruses.

To read more, click here.