More people showing signs of illness from mild strain of bird flu, British authorities say

Four more people have fallen ill after being in contact with farmworkers or poultry affected by a strain of bird flu in north Wales, British health authorities said Saturday.

The new suspected cases come a day after seven people tested positive for the H7N2-type virus _ a far milder form of bird flu than the deadly H5N1 strain.

The Health Protection Agency, which is an independent body, said all the new cases had symptoms which included conjunctivitis and had direct contact with sick poultry or farmworkers confirmed to have contracted H7N2.

The H7 subtype of bird flu is believed to be less virulent than H5 but has sickened humans in the past, notably in the Netherlands in 2003, when one person died following a H7 outbreak.

The mortality rate from H7 viruses is far lower than for H5N1, which experts say causes death in around half of human cases.

The illnesses were reported earlier in the week after a batch of chickens died at a small farm in Wales.

Veterinary officials confirmed Thursday that the birds had died of H7N2, and the Health Protection Agency confirmed late Friday that four people tested positive for H7N2.

The remaining chickens were slaughtered, and Welsh officials said Saturday that birds from a second farm were being tested for the virus.