According to the Centers for Disease Control and Prevention (CDC), three cases of a new flu virus have been confirmed. These originated in pigs but apparently spread from person to person, in three Iowa children.
According to Arnold Monto, a flu expert and professor at the University of Michigan School of Public Health, there is no reason to fear the beginning of a new pandemic. He said, “I don't think this is anything to worry about for the moment… We have known that swine viruses get into humans occasionally, transmit for a generation or two and then stop. The issue is whether there will be sustained transmission (from person to person) - and that nearly never happens.”
The CDC has counted a total of 18 cases of this new virus, an influenza A strain known as S-OtrH3N2, in two years. That suggests that it's not spreading quickly or easily, explained William Schaffner, a professor at the Vanderbilt University School of Medicine and spokesman for the Infectious Diseases Society of America.
Schaffner added that that flu viruses mutate and swap genes all the time. Infectious disease experts may only be noticing these new viruses because of better technology, he said.
The children, who live in rural Webster and Hamilton counties, did not become seriously ill, said Dr. Patricia Quinlisk, medical director for the Iowa Department of Public Health. “We have pretty good evidence of person-to-person spread,” Quinlisk said. “None of the children or anyone around them had exposure to swine, turkeys or other sources.”
In the new cases, it appears that one of the children transmitted the flu to the other two, and none of them had any animal exposure, Quinlisk said. She declined to identify the children or their ages, saying only they were younger than 18. No further cases have been identified in the past week, she said.
The H1N1 swine flu pandemic began in 2009 after flu viruses mutated to create a new strain that humans had never encountered before, leaving everyone vulnerable to infection. Although the H1N1 pandemic proved to be relatively mild, doctors fear new flu strains because of their lethal history. In 1918, a new flu strain killed more than 20 million people.
All three of the Iowa children had mild illness, the CDC reports. The virus also seems treatable with standard anti-viral drugs, Schaffner noted. The 10 cases of H3N2 in 2011 also have been spread throughout the USA - in Pennsylvania, Maine, Indiana and Iowa - which doesn't indicate a disease “cluster” or outbreak, Schaffner further added.
“People need to be most concerned about the regular, everyday seasonal flu,” Quinlisk said. CDC officials have asked states across the country to be vigilant in looking for it, said Dr. Joe Bresee, the agency's influenza and epidemiology branch chief.
The current seasonal flu vaccine being offered by doctors and clinics was not developed to protect against the H3N2 virus. It contains some antigens similar to a flu virus that circulated in the 1990s, so some people who had the flu then or were vaccinated could have some immunity, but it's not clear how much, Quinlisk said. The Iowa children apparently had not been vaccinated, she added.
The best prevention for the new flu, as with any flu, is to wash hands frequently, cover coughs and sneezes and limit spread of germs by staying home when one is sick, health officials said.
Human protein MxA restricts H5N1, but virus mutations raise alarms