Friday, December 23, 2011

CDC: Variant Influenza Strains



# 6030


The CDC today has posted a brief summary covering the recent emergence of variant swine-origin influenza strains, and indicates that they will be using the new nomenclature released by the WHO/FAO/OIE earlier today.


I’ve reproduced the statement below (slightly reformatted for readability).  Follow the link to go to the original webpage.



States reporting the new A(H3N2)v virus since July. – Source CDC



Information on Variant Influenza A Viruses

Novel influenza A viruses that normally circulate in animals may infect humans. Following discussion among international human and animal health agencies, these viruses will now be referred to as “variant influenza viruses” and, as an abbreviation going forward, will be designated with a “v”; recent examples include A(H3N2)v, A(H1N1)v, and A(H1N2)v.


In the second half of 2011, a number of U.S. residents were found to be infected with influenza A variant viruses, especially A(H3N2)v. Investigations have revealed human infections with these viruses following contact with swine as well as limited human-to-human transmission.


While this virus has been detected in U.S. swine, it's unknown how widespread it is. It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur. While there is no evidence that sustained human to human transmission is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread.


So far, the severity of illnesses associated with this virus has been similar to the severity of illnesses associated with seasonal flu virus infections. Limited serologic studies indicate that adults may have some pre-existing immunity to this virus while children do not.


CDC is closely monitoring human infections with all novel influenza viruses, including H3N2v viruses, and will provide more information as it becomes available.

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