CHARLESTON, W.Va. (AP) — Health officials said they are investigating after several people developed a flu-like illness after working closely with pigs that exhibited respiratory symptoms and fever at a county fair.

The state Department of Health and Human Resources said the H3N2v strain of influenza A was confirmed on at least one human test Tuesday. The sample has been forwarded to the Centers for Disease Control and Prevention for Confirmation.

The illnesses occurred at the Jackson County Fair. Dr. Ayne Amjad, the state’s health officer, said in a statement that symptoms such as fever, runny nose, sore throat, cough or congestion usually show up one to three days after exposure to infected animal livestock at an outdoor event.

The statement that swine influenza viruses may circulate in pig populations throughout the year and do not usually infect humans. The same antiviral drugs used to treat seasonal influenza can also be used for treatment of swine flu infection in humans.

Residents are encouraged to take routine precautions when visiting animal exhibits, including washing hands with soap and water before and after exposure to animals and avoid taking personal items, food or drinks into swine barns or areas with animals.

–Associated Press