Twelve new cases of influenza A/H3N2 variant virus were identified in Hawaii, Indiana and Ohio in the past week, making 29 total cases since the virus was first detected in humans in July 2011, CDC officials said during a press briefing today.
“Each of the 16 total cases identified in the past two weeks reported contact with swine,” Joseph Bresee, MD, medical epidemiologist in the influenza division at the CDC, said in a media briefing. “In 15 of these cases, contact with the swine occurred while attending or exhibiting swine at an agricultural fair. All cases have been laboratory-confirmed by the CDC.”
According to Bresee, no human-to-human spread of the influenza A/H3N2 variant virus has been identified in the most recent cases. However, limited transmission from person to person may have occurred in three cases in the fall of 2011.
Of the 16 recent cases, 13 of them were among children, which is consistent with data that indicate that children are more susceptible to the infection, Bresee said. No hospitalizations or deaths occurred with the most recent 16 cases, but there were three hospitalizations in the fall of 2011 related to the virus. All of the hospitalizations occurred in people with underlying diseases that put them at high risk for severe influenza.
To avoid the virus, Bresee said the following are important messages: wash your hands before and after contact with swine; avoid drinking and eating around the animals and do not take food or beverages in with the animals; and avoid contact with swine if you have a condition that puts you at high risk for serious complications from influenza, such as lung disease or diabetes.
“Because most cases occurred among people who had contact with swine in the setting of agricultural fairs, special attention should be paid to preventing transmission in these settings, especially since many of these fairs are ongoing now,” Bresee said.
Bresee said that medications that have been effective at preventing and treating seasonal influenza are likely to be effective at treating this variant virus infection. A vaccine for the variant virus has been prepared and clinical trials are planned.
“CDC, along with state and local health departments and our colleagues in animal health, will continue to monitor cases and provide information on how to prevent them,” Bresee said.