(CBS/AP) An increase in swine flu cases has the Centers for Disease Control and Prevention warning Americans to be especially careful around state and county fairs this summer.
With the fair season in full swing, health officials want attendees to avoid taking food and drinks into barns and to wash their hands after they're near animals. Pregnant women, young children, the elderly and people with weakened immune systems are especially at risk for developing the flu strain.
CDC officials say 29 human cases of the new strain of the H3N2 swine flu (dubbed H3N2v for "variant") have been confirmed in the last year, including 12 this week. Ten of the new cases were linked to the Butler County Fair in southwest Ohio, which ended last weekend.
None of the cases have been tied to human-to-human transmission and all 12 of the new patients had close contact with swine prior to getting sick. The two other new cases occurred in Hawaii and Indiana.
"While the viruses identified in these cases are genetically related, separate swine exposure events in each state are associated with infection and there is no indication that the cases in different states are related," the CDC said during a Friday press conference discussing its latest FluView Surveillance Report.
The new flu has a gene from the 2009 pandemic strain that might make it more contagious. But so far, the strain hasn't spread easily, and recent cases have been mild.
Symptoms are similar to that of other types of influenza and include fever and respiratory symptoms, such as cough and runny nose. Other possible symptoms include body aches, nausea, vomiting or diarrhea.
The CDC is collaborating with the World Health Organization on tracking H3N2.