KUWAIT CITY, 5 April 2007 — Preliminary tests for bird flu were positive on four Bangladeshi workers who had been culling infected chickens in Kuwait, a medical source said yesterday, but they have not been officially confirmed.

This would be the first cases of bird flu affecting humans in the Gulf region.

“The first test on the four men was positive,” the source said, requesting anonymity. “We have taken blood samples for a second test to reconfirm the initial results. We expect the outcome within hours.

Health Ministry spokesman Ahmad Al-Shatti said an official statement would be made today, after tests results were reviewed, as to whether the four were indeed infected.

The ministry said specimens have been sent to the World Health Organization (WHO) reference laboratory in Egypt for confirmation. “These measures are in line with recommendations by WHO for guidelines for the diagnosis and announcement of bird flu cases in humans,” he said.

The four workers were admitted to Kuwait’s infectious diseases hospital with flu-like symptoms on Tuesday. The men have been isolated in a special ward and were still at the hospital yesterday.

Since the outbreak of bird flu in Kuwait, 22 people have been admitted to hospital on suspicion of being infected, but later discharged after confirming they were healthy.

The Bangladeshis were part of official teams culling and burying hundreds of thousands of chickens in Wafra, south of Kuwait City on the Saudi border.

Kuwait has culled about 1.7 million birds, most of them egg-laying chickens in four commercial poultry farms, since confirming in February an outbreak of the H5N1 strain of the bird flu virus that is dangerous to humans.

A total of 106 cases of the strain have so far been confirmed in birds.

In November 2005, Kuwait announced the first case of a bird infected with the H5N1 strain — a flamingo at a seaside villa. The H5N1 strain, the most aggressive form, has killed 170 people worldwide, according to WHO, and seen millions of birds destroyed.

H5N1 is an avian influenza subtype with pandemic potential, since it might ultimately adapt into a strain that is contagious among humans.