A new flu virus linked to pigs but spread by people has been detected in three children in Iowa, raising fears of its wider spread.

“We have pretty good evidence of person-to-person spread,” said Dr. Patricia Quinlisk, medical director for the Iowa Department of Public Health.

The new H3N2 virus appears to be more transmissible than H1N1, the virus at the center of the “swine flu” pandemic of 2009. The new virus is made up of human, bird, H1N1 and swine flu components, officials at the Centers for Disease Control and Prevention said. The new virus was likely created when a pig was infected with both H1N1 and H3N2 at the same time.

Earlier cases of H3N2 were identified in Indiana, Pennsylvania, and Maine beginning in July of this year. However, in these cases, the patients had direct or indirect exposure to pigs; none of the Iowa kids affected had any animal exposure.

The new flu strain causes all the expected symptoms: Fever, cough, fatigue, body aches, and loss of appetite.

The CDC is asking health officials in all states to be on the lookout for spread of the new H3N2 bug. The current flu vaccine may provide some protection against the new H3N2 strain.