Aug 2, 2012 (CIDRAP News) – Nine people in Ohio and one in Indiana, all of whom had visited county fairs or had contact with pigs, have tested positive for variant swine-origin H3N2 influenza, health officials in the two states have announced, raising the apparent number of such flu cases reported in the past year to 28.
Variant H3N2 (H3N2v) flu cases have been confirmed in 9 of 10 people who were tested after they had symptoms following contact with pigs at the Butler County Fair in Hamilton, Ohio, said Robert Jennings, a spokesman for the Ohio Department of Health (ODH), today. He told CIDRAP News that the 10th person is being retested. Yesterday officials said the illnesses resembled seasonal flu, and none of the patients were hospitalized.
The nine cases apparently make the Butler County outbreak the biggest one since this H3N2v strain emerged in the United States last summer. Most of the patients have been children, and most had contact with pigs.
In neighboring Indiana, the State Department of Health announced late yesterday that it identified a case of "variant influenza A" in a person from Jackson County who had contact with swine.
The statement gave no further details about the case, but Jackson County lies just southeast of Monroe County, where several people and pigs were being tested for flu in connection with the Monroe County Fair, according to reports yesterday. Illness among pigs had prompted officials to close the swine barn at the fair, and some people who had visited the fair were sick, according to the earlier reports.
The latest case confirmations come 8 days after Indiana officials reported four H3N2v cases in people who had exhibited pigs at the LaPorte County Fair in northwestern Indiana. Also, on Jul 31 the Hawaii Department of Health reported that a Maui resident had tested positive for the same strain.
In a press release today, the ODH said the strain in the nine new cases matched the strain found in the four Indiana cases last week. The Ohio cases were confirmed by the US Centers for Disease Control and Prevention (CDC), the department said.
The H3N2v strain in recent cases is described as a reassortant that includes the M or matrix gene from the 2009 H1N1 virus. The first two cases with this particular strain were identified in Indiana and Pennsylvania in August 2011, according to previous reports, and several more cases cropped up late last summer and fall. The four cases reported in Indiana last week brought the total to 17, and the reports yesterday and today add 11 more.
Pigs that were shown at the Butler County Fair in Ohio and the Monroe County Fair in Indiana are besting tested for the H3N2v strain. No test results have been announced by the state agriculture departments as of this writing.
Denise Derrer, spokeswoman for the Indiana State Board of Animal Health, said today that the swine test results were still pending. Meanwhile, she said veterinary officials have checked 2,000 pigs brought to the Indiana State Fair in Indianapolis and found none with a temperature too high to be admitted.
Aug 2 ODH press release
Aug 2 Indiana press release
Aug 1 CIDRAP News story "Reports from 3 states suggest more variant H3N2 cases"
Jul 25 CIDRAP News story "Four novel H3N2 cases linked t pigs in Indiana"
Butler County press release
CDC information on variant swine-origin flu infections since 2005