Norovirus, a gastrointestinal illness that is the most common cause of the stomach flu, is making its way through the region.

The illness is making especially light work of schools in the area. Earlier this month, about 85 students were infected by norovirus at George Washington University, and last week several had the bug at Howard University. Friday, about 100 students and staff members at Willow Springs Elementary School in Fairfax County were reported sick, and officials canceled weekend activities, dousing the facility with bleach.

How can you stay healthy?

Public-health officials says that the best way to avoid catching norovirus is to carefully wash your hands with soap and water, especially after using the toilet or changing diapers and always before eating or preparing food. Alcohol-based hand sanitizers are not a substitute for washing with soap and water, according to the U.S. Centers for Disease Control and Prevention.

People who are infected with norovirus shouldn’t prepare food for others while they have symptoms and for 3 days after they recover.

People can become infected by eating food or drinking liquids contaminated by the virus; by touching contaminated surfaces or objects and then placing their hands in their mouth; and by having direct contact with an infected person.

After an episode of illness, such as vomiting or diarrhea, people should immediately clean and disinfect contaminated surfaces with a bleach-based household cleaner. Soiled clothing or linens should also immediately be washed in hot water.

Symptoms and length

Those who are exposed to the affliction can look forward to a hellish 24 to 48 hours:

• Norovirus symptoms begin 12 to 48 hours after exposure. The most common symptoms are diarrhea, vomiting and stomach pain, according to the CDC.

• Most people get better within one to two days. If you get sick: Stay home, wash your hands, and stay hydrated.

Though norovirus first gained infamy after sickening 300 passengers aboard a cruise ship in 2003, the sickness afflicts people of all ages in a variety of settings, according to the Centers for Disease Control and Prevention.