CDC Confirms New Flu Virus in Iowa Children, No Cause for Panic
Influenza, commonly known as the flu, is an infectious disease resulting from a virus that infects birds and mammals, including humans, and is transmitted through the air or by direct contact with secretions or contaminated surfaces. In some cases, influenza viruses can cause pandemics, or a rash of infectious disease that spreads through a population across a large region, as did the H1N1 (Swine Flu) pandemic in 2009. Although the United States Centers for Disease Control and Prevention (CDC) have confirmed a small number of cases of a new flu virus originating from pigs infecting children in Iowa, they stress that there is no cause to panic, as the virus has very limited human-to-human transmission at this time.
The CDC has been following the influenza A strain known as S-OtrH3N2 for two years. It is a new variant of the H3N2 virus that is common during seasonal flu time but contains one gene from the H1N1 pandemic virus and genes from other influenza viruses circulating among North American swine. A total of 18 cases have been reported since 2009 (10 since July of this year), suggesting that it is not spreading quickly or easily, says William Schaffner, a professor at the Vanderbilt University School of Medicine and spokesman for the Infectious Diseases Society of America.
Most H3N2 subtypes have been isolated from pigs. In fact, the cases of this flu variant found prior to this month all occurred in patients who had been recently exposed to pigs either directly or indirectly. These cases occurred in Pennsylvania, Maine, and Indiana.
On November 20 this year, the CDC confirmed three cases of the S-OtrH3N2 virus in three children across two counties in Iowa. Although Iowa is the nation’s largest hog-raising state, none of the children had been near swine although they had been in contact with one another. All three children had mild illness and the virus was treatable with standard anti-viral drugs. No other household family members have been ill.
But please don’t panic yet, warns Arnold Monto, a flu expert and professor at the University of Michigan School of Public Health. "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."
As part of “routine preparedness,” the CDC has already produced a “candidate vaccine virus” that could be used against this new influenza strain and it has been given to vaccine manufacturers.
This year, the CDC says, the currently available flu vaccine should provide adults with limited protection from the new virus, but probably not children. For any patients who are suspected to have swine flu infection, doctors are encouraged to treat them with Tamiflu where appropriate and to obtain nose and throat specimens to be sent to state public health labs.
Sources Include: Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report (MMWR), November 23, 2011.