Mild bird flu identified in US breeding hens

A Tennessee flock of 15,000 breeder hens has been culled after tests revealed a mild strain of avian influenza. The birds, which were being raised under contract for Tyson Foods, showed no signs of illness and there was no threat to human health, said the company.

Tests revealed presence of H7N9 flu antibodies, not the highly pathogenic H5N1 strain identified in Asia, Europe and Africa. The outbreak in Tennessee is unrelated to the H1N1 influenza virus termed swine flu.

Tyson is to step up its surveillance procedures for avian flu in its breeders’ flocks.

Commercial chickens

The company produces, distributes and markets chicken, beef, pork, prepared foods and related allied products. Its website states: “Tyson Foods and other U.S. chicken producers take great care to prevent chickens from being exposed to diseases. Unlike birds in Asia, which are primarily raised outdoors, commercial chickens in the U.S. are kept indoors, away from wild birds and other means of spreading diseases.”

Meanwhile, new cases of the highly pathogenic H5N1 strain of avian influenza have been confirmed in Egypt and Viet Nam, according to the World Health Organisation (WHO).

Egypt’s ministry of health has reported a new confirmed human case bringing the total number of human cases to 68, of which 23 have proved fatal.

In Viet Nam, a new fatality brings the total number of deaths due to avian influenza to 56 and the total number of cases to 111.

Swine flu

To date WHO reports 1893 cases of swine flu (influenza A H1N1 infection) in 23 countries including deaths only in Mexico and US.

Laboratory confirmed cases have been reported in Austria (1), Canada (165), China, Hong Kong Special Administrative Region (1), Colombia (1), Costa Rica (1), Denmark (1), El Salvador (2), France (5), Germany (9), Guatemala (1), Ireland (1), Israel (4), Italy (5), Netherlands (1), New Zealand (5), Portugal (1), Republic of Korea (2), Spain (73), Sweden (1), Switzerland (1) and the United Kingdom (28).