Bird flu hits another farm in South Korea

Nov 29 2006

A second outbreak of the virulent H5N1 strain of bird flu at another poultry farm has been confirmed by South Korean authorities; the farm is just 3 km from the first case in North Cholla province in the country's southwest.

According to the agriculture ministry, as many as 600 chickens have died but no people in or around both infected farms appear to have been infected; 6,000 chickens died in the first outbreak.

The officials say test results have shown that the highly pathogenic H5N1 bird flu was the culprit and strict quarantine measures have been imposed around the area.

The South Korean health ministry says all poultry within a 500 metre radius of the latest infected farm will be culled, this amounts to 236,000 poultry; 75,500 poultry have already been culled and 6.6 million eggs disposed of.

Authorities are also said to be considering culling as many as 600 cats and dogs living in the area despite the fact that no scientific evidence exists which indicates humans can catch bird flu from them, and the Food and Agriculture Organization (FAO) of the United Nations, says the culling of such creatures is unnecessary.

The two farms lie directly under a flight path for migratory birds heading south from Russia, Mongolia and Kazakhstan, and are about 170 km south of Seoul.

There is widespread concern that other parts of South Korea might have also been hit and the situation is a setback for the country as this is the first outbreak of the deadly virus in three years.

That outbreak, between December 2003 and March 2004, resulted in 5.3 million birds being killed and over $1 billion being spent on preventing the spread of the disease.

At the time nine South Korean workers involved in the culling were infected with the H5N1 virus, but fortunately none developed major illnesses.

The vast majority of human bird flu cases involving the H5N1 virus have been linked to direct or indirect contact with infected fowl.

Indonesia said on Tuesday a 35-year-old woman died of the disease, bringing that country's death toll to 57, the highest for any nation.

H5N1 bird flu remains essentially a disease of birds and almost all those infected had been in close contact with diseased birds.

Since 2003, outbreaks have been confirmed in about 50 countries and territories and according to the World Health Organisation it has killed in excess of 150 since then and sickened another 260.

China has banned imports of poultry and poultry products from South Korea along with Japan.

Chinese authorities are also urging those provinces nearest to South Korea to monitor and penalise for the smuggling of poultry products across the borders and to intensify their efforts in combating the spread of the disease, by closely monitoring personnel and vehicles entering China.

CDC Key Facts on avian influenza A (H5N1)

What is the avian influenza A (H5N1) virus that has been reported in Africa, Asia, Europe, and the Near East?
Influenza A (H5N1) virus - also called “H5N1 virus” - is an influenza A virus subtype that occurs mainly in birds, is highly contagious among birds, and can be deadly to them.

Outbreaks of avian influenza H5N1 occurred among poultry in eight countries in Asia (Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam) during late 2003 and early 2004. At that time, more than 100 million birds in the affected countries either died from the disease or were killed in order to try to control the outbreaks. By March 2004, the outbreak was reported to be under control.

Beginning in June 2004, however, new outbreaks of influenza H5N1 among poultry and wild birds were reported in Asia. Since that time, the virus has spread geographically. Reports of H5N1 infection in wild birds in Europe began in mid-2005. In early 2006, influenza A H5N1 infection in wild birds and poultry were reported in Africa and the Near East.

Human cases of influenza A (H5N1) infection have been reported in Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Thailand, Turkey, and Vietnam.

What are the risks to humans from the current H5N1 outbreak?
H5N1 virus does not usually infect people, but more than 200 human cases have been reported. Most of these cases have occurred from direct or close contact with infected poultry or contaminated surfaces; however, a few cases of human-to-human spread of H5N1 virus have occurred.

So far, spread of H5N1 virus from person to person has been rare, limited and unsustained. Nonetheless, because all influenza viruses have the ability to change, scientists are concerned that H5N1 virus one day could be able to infect humans and spread easily from one person to another. Because these viruses do not commonly infect humans, there is little or no immune protection against them in the human population.

If H5N1 virus were to gain the capacity to spread easily from person to person, an influenza pandemic (worldwide outbreak of disease) could begin. No one can predict when a pandemic might occur. However, experts from around the world are watching the H5N1 situation in Asia and Europe very closely and are preparing for the possibility that the virus may begin to spread more easily from person to person.

How is infection with H5N1 virus in humans treated?
Most H5N1 viruses that have caused human illness and death appear to be resistant to amantadine and rimantadine, two antiviral medications commonly used for treatment of patients with influenza. Two other antiviral medications, oseltamivir and zanamavir, would probably work to treat influenza caused by H5N1 virus, but additional studies are needed to demonstrate their current and ongoing effectiveness.

Is there a vaccine to protect humans from H5N1 virus?
There currently is no commercially available vaccine to protect humans against the H5N1 virus that is being detected in Asia and Europe. However, vaccine development efforts are taking place. Research studies to test a vaccine that will protect humans against H5N1 virus began in April 2005, and a series of clinical trials is under way.

What does CDC recommend regarding H5N1 virus?
In February 2004, CDC provided U.S. public health departments with recommendations for enhanced surveillance (“detection”) of H5N1 influenza in the country. Follow-up messages, distributed via the Health Alert Network, were sent to the health departments on August 12, 2004, February 4, 2005, and June 7, 2006; all three notices reminded public health departments about recommendations for detecting (domestic surveillance), diagnosing, and preventing the spread of H5N1 virus. The notices also recommended measures for laboratory testing for H5N1 virus.

Does CDC recommend travel restrictions to areas with known H5N1 outbreaks?
CDC does not recommend any travel restrictions to affected countries at this time. However, CDC currently advises that travelers to countries with known outbreaks of H5N1 influenza avoid poultry farms, contact with animals in live food markets, and any surfaces that appear to be contaminated with feces from poultry or other animals.

Is there a risk in handling feather products that come from countries experiencing outbreaks of avian influenza A (H5N1)?
The U.S. government has determined that there is a risk to handling feather products from countries experiencing outbreaks of H5N1 influenza

There is currently a ban on the importation of birds and bird products from H5N1-affected countries in Africa, Asia, and Europe. The regulation states that no person may import or attempt to import any birds (Class Aves), whether dead or alive, or any products derived from birds (including hatching eggs), from the specied countries. This prohibition does not apply to any person who imports or attempts to import products derived from birds if, as determined by federal officials, such products have been properly processed to render them noninfectious so that they pose no risk of transmitting or carrying H5Nl and which comply with the U.S. Department of Agriculture (USDA) requirements. Therefore, feathers from these countries are banned unless they have been processed to render them noninfectious. Additional information about the import ban is available on the USDA website. 

Is there a risk to importing pet birds that come from countries experiencing outbreaks of avian influenza A (H5N1)?
The U.S. government has determined that there is a risk to importing pet birds from countries experiencing outbreaks of H5N1 influenza. CDC and USDA have both taken action to ban the importation of birds from areas where H5N1 has been documented. There is currently a ban on the importation of birds and bird products from H5N1-affected countries in Africa, Asia, and Europe. The regulation states that no person may import or attempt to import any birds (Class Aves), whether dead or alive, or any products derived from birds (including hatching eggs), from the specified countries.

Can a person become infected with avian influenza A (H5N1) virus by cleaning a bird feeder?
There is no evidence of H5N1 having caused disease in birds or people in the United States. At the present time, there is no risk of becoming infected with H5N1 virus from bird feeders. Generally, perching birds (Passeriformes) are the predominate type of birds at feeders. While there are documented cases of H5N1 causing death in some Passeriformes (e.g., house sparrow, Eurasian tree-sparrow, house finch), in both free-ranging and experimental settings, none occurred in the U.S. and most of the wild birds that are traditionally associated with avian influenza viruses are waterfowl and shore birds.