A farm with a case of Avian influenza, also known as bird flu, is being investigated by the US Department of Agriculture (USDA). Authorities say the poultry in the farm has been quarantined after initial laboratory results were returned.

The Department of Agriculture describes the Avian influenza as the low pathogenic virus strain H7N3. Authorities add that the virus typically affects birds and extremely rarely affects humans.

The National Veterinary Services Laboratory, in Ames, Iowa is currently carrying out tests to determine exactly what type of disease it is.

All poultry within a six mile radius of the affected farm are being tested for Avian influenza.

Authorities say the Missouri Department of Agriculture, the Missouri Department of Health, as well as Senior Services are liaising closely with the USDA.

The farm is operated locally, but contracted with the food company Cargill.

Cargill Corp. says it will cull up to 15,000 younger poultry that have been exposed to older turkeys that tested positive to Avian influenza antibodies. The older poultry are being harvested at another part of Missouri. Apparently, meat from these birds is not hazardous to human health.

Cargill does not wish to release the name of the farm or its location.

Even though some birds appear to have the Avian flu virus antibody, none of them have any symptoms of the disease. However, the fact that they have the antibodies means they were exposed at some time and their immune systems have responded. They may have become infected by being in contact with migrating birds, drinking water, or scavenging on the ground.

Authorites say the concern is not for humans, who are in no danger, but for the animals.

Sources: USDA, Missouri Department of Agriculture

Written by Christian Nordqvist