The U.S. Centers for Disease Control and Prevention reported 12 additional human infections with influenza A (H3N2) variant virus. Ten cases of the infection, commonly known as swine flu, were in Ohio, with one case each in Indiana and Hawaii.
All reported cases occurred in people who had direct or indirect contact with swine before their illness. The 10 cases in Ohio were associated with attendance at a fair where reportedly ill swine were present. The case in Indiana also occurred in a person who attended a fair where swine were present.
The number of cases of infection detected since July 2011 is 29 — 10 in Ohio, seven in Indiana, three each in Iowa and Pennsylvania, two each in Maine and West Virginia and one each in Hawaii and Utah. Of the cases, 23 reported swine contact before illness onset, and 19 were associated with fairs where swine were present.
Most human illness with H3N2v virus infection has resulted in signs and symptoms of influenza (fever, cough, runny nose, sore throat, muscle aches). Three hospitalizations have occurred, all in people at high risk of serious influenza-related complications.
According to the U.S. Department of Agriculture’s swine influenza surveillance, this H3N2 virus with the pandemic M gene has been detected in swine in a number of states and may be circulating widely in U.S. swine. However, influenza viruses have not been shown to be transmissible to people through eating properly handled and prepared pork or other products derived from pigs.
Acquisition of the M gene from the 2009 H1N1 virus may allow H3N2v viruses to be more transmissible from pigs to people and from person to person, the CDC noted.
The CDC continues to advise people to take recommended precautions when interacting with pigs or their environments, including frequent hand washing and avoiding contact with pigs that appear ill.
Preventive actions applicable to people raising swine, showing swine at fairs or attending fairs include: frequent hand-washing with soap and running water before and after exposure to animals; avoiding eating, drinking or putting things in your mouth while in animal areas; avoiding close contact when possible with animals that look or act ill; avoiding contact with pigs if you are experiencing flu-like symptoms or, if contact is necessary, using appropriate preventive measures and practicing good respiratory and hand hygiene.
Additional considerations
Children younger than 5, adults older than 65, pregnant women and people with certain chronic conditions are at high risk of serious complications from influenza, and should consider avoiding exposure to pigs and swine barns this summer — especially if sick pigs have been identified.
Studies conducted by the CDC have indicated that children younger than 10 would have little to no immunity against the H3N2v virus, whereas adults may have some cross-protective immunity. Most cases of H3N2v at this time have occurred in children.
Two FDA-approved drugs are expected to be effective in treating illness associated with H3N2v virus infection. The antiviral drugs oseltamivir (Tamiflu) and zanamivir (Relenza), which are used to treat infection with human seasonal influenza viruses, also are expected to be effective in treating H3N2v virus. Antiviral treatment is most effective when started as soon as possible after illness onset.
Signs and symptoms of H3N2v virus infection cannot be differentiated from those caused by other respiratory infections, including seasonal influenza virus infection. Rapid influenza diagnostic tests may turn up false negative results for H3N2v virus in human respiratory specimens. If H3N2v virus infection is suspected because of recent exposure to pigs or to an ill person who had contact with pigs, testing of respiratory specimens should be done at a state health department.
For more information on preventing H3N2v illness, visit http://1.usa.gov/wrhMsD.
All reported cases occurred in people who had direct or indirect contact with swine before their illness. The 10 cases in Ohio were associated with attendance at a fair where reportedly ill swine were present. The case in Indiana also occurred in a person who attended a fair where swine were present.
The number of cases of infection detected since July 2011 is 29 — 10 in Ohio, seven in Indiana, three each in Iowa and Pennsylvania, two each in Maine and West Virginia and one each in Hawaii and Utah. Of the cases, 23 reported swine contact before illness onset, and 19 were associated with fairs where swine were present.
Most human illness with H3N2v virus infection has resulted in signs and symptoms of influenza (fever, cough, runny nose, sore throat, muscle aches). Three hospitalizations have occurred, all in people at high risk of serious influenza-related complications.
According to the U.S. Department of Agriculture’s swine influenza surveillance, this H3N2 virus with the pandemic M gene has been detected in swine in a number of states and may be circulating widely in U.S. swine. However, influenza viruses have not been shown to be transmissible to people through eating properly handled and prepared pork or other products derived from pigs.
Acquisition of the M gene from the 2009 H1N1 virus may allow H3N2v viruses to be more transmissible from pigs to people and from person to person, the CDC noted.
The CDC continues to advise people to take recommended precautions when interacting with pigs or their environments, including frequent hand washing and avoiding contact with pigs that appear ill.
Preventive actions applicable to people raising swine, showing swine at fairs or attending fairs include: frequent hand-washing with soap and running water before and after exposure to animals; avoiding eating, drinking or putting things in your mouth while in animal areas; avoiding close contact when possible with animals that look or act ill; avoiding contact with pigs if you are experiencing flu-like symptoms or, if contact is necessary, using appropriate preventive measures and practicing good respiratory and hand hygiene.
Additional considerations
Children younger than 5, adults older than 65, pregnant women and people with certain chronic conditions are at high risk of serious complications from influenza, and should consider avoiding exposure to pigs and swine barns this summer — especially if sick pigs have been identified.
Studies conducted by the CDC have indicated that children younger than 10 would have little to no immunity against the H3N2v virus, whereas adults may have some cross-protective immunity. Most cases of H3N2v at this time have occurred in children.
Two FDA-approved drugs are expected to be effective in treating illness associated with H3N2v virus infection. The antiviral drugs oseltamivir (Tamiflu) and zanamivir (Relenza), which are used to treat infection with human seasonal influenza viruses, also are expected to be effective in treating H3N2v virus. Antiviral treatment is most effective when started as soon as possible after illness onset.
Signs and symptoms of H3N2v virus infection cannot be differentiated from those caused by other respiratory infections, including seasonal influenza virus infection. Rapid influenza diagnostic tests may turn up false negative results for H3N2v virus in human respiratory specimens. If H3N2v virus infection is suspected because of recent exposure to pigs or to an ill person who had contact with pigs, testing of respiratory specimens should be done at a state health department.
For more information on preventing H3N2v illness, visit http://1.usa.gov/wrhMsD.
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