H7N2
Encyclopedia
H7N2 is a subtype of the species Influenza A virus
Influenzavirus A
Influenza A virus causes influenza in birds and some mammals and is the only species of Influenzavirus A. Influenzavirus A is a genus of the Orthomyxoviridae family of viruses. Strains of all subtypes of influenza A virus have been isolated from wild birds, although disease is uncommon...

 (sometimes called bird flu virus).

A CDC
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 study following outbreaks of H7N2 in commercial poultry farms in western Virginia in 2002 concluded:
An important factor contributing to rapid early spread of AI virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off-farm. Because of the highly infectious nature of AI virus and the devastating economic impact of outbreaks, poultry farmers should consider carcass disposal techniques that do not require off-farm movement, such as burial, composting, or incineration.


One person in Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...

, US in 2002 and one person in New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

, US, in 2003 were found to have serologic evidence of infection from H7N2; both fully recovered.

An analysis of the New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 2003 case concluded that the H7N2 virus responsible could be evolving toward the same strong sugar-binding properties of the three worldwide viral pandemic
Pandemic
A pandemic is an epidemic of infectious disease that is spreading through human populations across a large region; for instance multiple continents, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a pandemic...

s in 1918, 1957 and 1968. (Human flu
Human flu
Human flu is a term used to refer to influenza cases caused by Orthomyxoviridae that are endemic to human populations . It is an arbitrary categorization scheme, and is not associated with phylogenetics-based taxonomy...

s and bird flus differ in the molecules they are good at binding with because mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s and bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s differ in the molecules on the cell surface to be bound with. Humans have very few cells with the bird sugar on its cell surface.) A study with ferret
Ferret
The ferret is a domesticated mammal of the type Mustela putorius furo. Ferrets are sexually dimorphic predators with males being substantially larger than females. They typically have brown, black, white, or mixed fur...

s showed that this H7N2 strain could be passed from mammal to mammal.

In February 2004, an outbreak of low pathogenic avian influenza (LPAI) A (H7N2) was reported on 2 chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

 farms in Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...

 and in four live bird markets in New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

 supplied by the same farms. In March 2004, surveillance samples from a flock of chickens in Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

 tested positive for LPAI H7N2. It is likely that this was the same strain.

On 24 May 2007, an outbreak of H7N2 was confirmed at a poultry farm near Corwen
Corwen
Corwen is a town and community in the county of Denbighshire in Wales; it was previously part of the county of Meirionnydd). Corwen stands on the banks of the River Dee beneath the Berwyn mountains. The town is situated west of Llangollen and south of Ruthin...

, in Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

 from tests on chickens that died from H7N2. The owners of the Conwy farm bought 15 Rhode Island Red
Rhode Island Red
The Rhode Island Red is a breed of chicken . They are a utility bird, raised for meat and eggs, and also as show birds. They are a popular choice for backyard flocks because of their egg laying abilities and hardiness. Non-industrial strains of the Rhode Island Red are listed as recovering by the...

 chickens two weeks prior but all died from H7N2. The 32 other poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...

at the site were slaughtered. A one kilometer exclusion zone was put in force around the property in which birds and bird products cannot be moved and bird gathering can only take place under licence. Nine people who were associated with the infected or dead poultry and reported flu-like symptoms were tested. Four tested positive for evidence of infection from H7N2 and were successfully treated for mild flu. In early June it was discovered that the virus had spread to a poultry farm 70 miles (113 km) away near St. Helens in north-west England. All the poultry at the farm were slaughtered and a 1 km exclusion zone imposed.

Sources and notes


Further reading


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK