H2N2

H2N2 is a subtype of the species avian influenza virus(bird flu virus). H2N2 has mutated into various strains including the Asian Flu strain (now extinct in the wild), H3N2, and various strains found in birds.

It is suspected of causing a human pandemic in 1889. [1][2]

Asian flu

The "Asian Flu" was a pandemicoutbreak of avian influenzathat originated in Chinain 1957and spread worldwide that same year, lasting until 1958. Estimates of worldwide casualty numbers vary widely, ranging from one million to four million people.

Asian Flu was of the H2N2 strain (a notation that refers to the configuration of the hemagglutininand neuraminidaseproteinsin the virus) of type A influenza, and a flu vaccinewas developed in 1957to contain its outbreak.

The Asian Flu strain later evolved via antigenic shiftinto H3N2which caused a milder pandemic from 1968to 1969.

Test kits

From October 2004to February 2005, some 3,700 test kits of the 1957H2N2 virus were accidentally spread around the world from the College of American Pathologists(CAP). CAP assists laboratories in accuracy by providing unidentified samples of viruses; private contractor Meridian Bioscience in Cincinnati, U.S., chose the 1957strand instead of one of the less deadly avian influenza virussubtypes. "CAP spokesman Dr. Jared Schwartz said Meridian knew what the virus was but believed it was safe. In selecting it, the company had determined that the virus was classified as a biosafety level 2 (BSL-2) agent, which meant it could legally be used in the kits. [...] Before the problem came to light, the CDChad made a recommendation that the H2N2 virus be reclassified as a BSL-3 agent, Gerberding said. She promised to speed up the reclassification. The CDC determines the classifications in collaboration with the National Institutes of Health. In BSL-3 labs, agents are handled with equipment designed to prevent any airborne contamination and resulting respiratory exposure." [3]The 1957H2N2 virus is considered deadly and the U.S. government called for the vials containing the strain to be destroyed.

"CDCofficials reported on April 21that 99% of the samples had already been destroyed. News reports on April 25said the last samples outside the United Stateshad been destroyed at the American University of Beirut in Lebanon, after they were found at the Beirut airport. Earlier reports said H2N2 samples were sent to 3,747 labs under CAP auspices and to about another 2,700 labs certified by other organizations. All but about 75 labs that received the CAP samples were in the United States." [4]

"In the United States, there is no government regulation over the 1957flu strain. In fact, federal officials at the CDCdo not even know how many U.S. laboratories keep this deadly strain in their viral libraries." [5]

Sources

• New Scientist: Bird Flu
• Pandemic-causing 'Asian flu' accidentally released
• Asian Lab Opens 'Accidental' Parcel With Deadly Flu
• Persistence of Q strain of H2N2 influenza virus in avian species: antigenic, biological and genetic analysis of avian and human H2N2 viruses

Further reading

• Pandemic preparedness: lessons learnt from H2N2 and H9N2 candidate vaccines
• Interim CDC-NIH Recommendation for Raising the Biosafety Level for Laboratory Work Involving Noncontemporary Human Influenza Virusesde:Asiatische Grippe

es:Gripe asiática nl:Aziatische griep pt:Gripe asiática sv:asiaten zh:????

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/H2N2 Wikipedia article H2N2.