Wild swans in the U.S. found to have strain of H5N1 bird flu

Officials at the Agriculture Department in the United States have found two swans in a Michigan gaming area with possibly another strain of the bird flu virus.

It seems the routine tests were part of an increased surveillance program and they revealed that two of twenty swans were carrying a low-pathogenic strain of H5N1 but not the deadly form currently appearing again in parts of Asia.

Following a $29 million funding boost in December, to date more than 10,000 wild birds have been tested.

A low-pathogenic strain produces less disease and mortality in birds than a high-pathogenic version does.

The swans had shown no sign of sickness and tests are underway which are expected to confirm there is no threat to humans.

The highly pathogenic H5N1 strain that has spread through birds in Asia, Europe and Africa, has to date killed at least 139 people.

Ron DeHaven, head of the Animal and Plant Health Inspection Service has been quick to reassure the public that the outbreak is not the introduction of the lethal virus into North America and health officials do not believe the infected swans came in contact with U.S. commercial poultry.

Low-pathogenic strains of H5N1 have previously been found in wild birds in the United States in 1975 and 1986 and a similar strain was found in Canada last year.

It is quite common for mild and low pathogenic strains of bird flu to appear in the wild bird population but scientists are always alert to cases as swans in particular are regarded as harbingers of diseases in bird populations.

The Department of Health and Human Services say it is rarely fatal in birds and there is no need for public health and medical authorities to take any special actions as a result of this information.

The current deadly strain of H5N1 bird flu has forced hundreds of millions of birds worldwide to be culled but has not as yet been found in the United States.

Although the virus remains predominantly a disease of birds experts believe the H5N1 virus could mutate and spread easily from person to person, triggering a pandemic with the potential to kill millions.