CHARLESTON, W.Va. --A recent bout of gastrointestinal illness in Kanawha County -- or the "stomach bug" -- is likely caused by norovirus, health officials say.The Kanawha County Health Department has received an increase in community calls for information about how to stop the spread of gastrointestinal illness with symptoms including stomach pain, nausea, diarrhea and vomiting, fever, headache and body aches, according to a release from the Kanawha-Charleston Health Department."I think it's safe to say ... it's making its way through our community," said Dr. Rahul Gupta, executive director of the health department.Each year, norovirus causes about 21 million illnesses, contributes to about 70,000 hospitalizations and causes about 800 deaths in the U.S., according to health officials.Because the health department and hospitals don't track the cases of norovirus, it's impossible to say how many in the community have been affected, Gupta said. Those who are treated at hospitals are likely treated for dehydration, he said. The virus is highly contagious, Gupta said. With influenza, around 1,000 particles of the virus are needed for transmission. Only 17 to 20 particles of norovirus are needed for a person to get the illness, Gupta said. The illness can be especially harmful and can cause hospitalizations in the elderly, very young children and those with underlying health conditions. Most other people recover completely in one to three days.The virus is spread by infected people and contaminated food, water and surfaces. Health officials say the best way to prevent the spread of the stomach bug is to wash your hands carefully with soap and water especially before eating, preparing or handling food. Hands also should be washed after using the toilet or changing diapers.There is no specific therapy for treating gastroenteritis, but infected people should stay home until the symptoms resolve and avoid getting dehydrated by drinking fluids and electrolytes. If symptoms get worse, consult a physician. In some cases, a person can spread the virus for up to two weeks after symptoms have stopped. Surfaces that are contaminated should be cleaned and disinfected using chlorine bleach or another disinfectant. Alcohol-based hand sanitizers don't kill the virus and should not be used as a substitute for washing hands, Gupta said."When in doubt, make sure you wash your hands well with soap and water," Gupta said. For more information, contact the health department at 304-344-5243 or visit www.kchdwv.org or www.cdc.gov/norovirus.Reach Lori Kersey at email@example.com or 304-348-1240.