KANSAS CITY, Mo. – New cases of H3N2 flu increased dramatically in the past week as health officials in Indiana confirmed 113 new cases of the flu virus on Aug. 8, with more cases expected to be confirmed during the week. State health officials had confirmed 11 cases of the flu statewide on Aug. 3.

In Ohio, new cases of H3N2 doubled to 30. Health officials in Ohio said the strain appears to be mild and is similar to seasonal flu that responds to treatment. The infected persons had direct contact with hogs at fairs. The Indiana State Department of Health said in a statement the agency had not yet found any cases of the disease in which it passed from human to human. The virus contains a version of the M gene, which scientists think may make it more easily transmissible in humans.

“It’s important for folks to remember this is a mild illness with symptoms similar to what we see with seasonal flu,” said State Health Commissioner Gregory Larkin, MD in a statement. “Because this is a relatively new strain of flu, only first seen in July of last year, a vaccine is not yet available. However, you can help to protect yourself by practicing thorough and frequent hand washing and by being mindful not to eat around barn animals.”

The Centers for Disease Control (CDC) is advising the general public to exercise precautions when attending fairs because there are more opportunities for interactions between pigs and people. During a recent teleconference, epidemiologists with the CDC said the only way to differentiate between the H3N2 and a seasonal influenza virus is to be tested.

"Folks infected with the H3N2 variant virus have very similar symptoms and signs of their illness compared with people infected with normal human seasonal viruses," said Joe Bresee, a medical epidemiologist with the CDC's influenza division during a recent teleconference. "They tend to get respiratory illness, they tend to get cough, sore throat, muscle aches, headaches. They tend to have self-resolving illnesses like with seasonal flu.

"They can be severe illnesses like seasonal flu, especially if you have underlying medical conditions that predispose you to severe illnesses with flu," he added. "So based on clinical symptoms alone, they really are difficult or impossible to tell apart."