South Korea has formally banned imports of all US poultry, and the EU has banned imports of live chicks and eggs from the US, after officials in the US state of Texas confirmed an outbreak of a highly pathogenic strain of bird flu there.

South Korea had already suspended imports of US chicken after an outbreak of bid flu was discovered in Delaware earlier this month, but the ban was not official, reported the Associated Press.

The European Commission said it was taking immediate action with the suspension of imports of live birds and eggs from all of the US.

The H5N2 strain, which was discovered in a Gonzales County flock, has been described as extremely infectious and fatal to poultry, but it is not believed to be transmissible to humans.

“Past experience with H5N2 viruses has indicated there is a low threat to public health,” Dr. Nancy Cox of the Centers for Disease Control was quoted by Reuters as saying. “Nevertheless as we move forward with this situation, we must keep an open mind and really monitor the situation as we go.” 

The discovery marks the first case of highly pathogenic bird flu found in the US since the mid-1980s, reported Reuters.

It is a different strain to the H5N1 virus, which has led to the deaths of more than 20 humans in Asia in recent weeks.