WASHINGTON (AP) – Wild birds are serving as carriers for bird flu, and the disease can be expected to spread along their migration routes, Health and Human Services Secretary Michael Leavitt said Friday.

First detected in Southeast Asia, the flu has now been found elsewhere, including Russia, Romania and Turkey.

“There is no reason to think that it will not go further,” Leavitt said in a briefing at the State Department.

Currently, the flu spreads primarily among birds, although there have been cases of it spreading from birds to humans, including more than 60 human deaths.

Health authorities fear that the flu will mutate into a form that can spread easily from human to human, potentially causing a worldwide pandemic like the one in 1918 that claimed millions of lives.

“If there is person-to-person transmission anywhere, then there is risk everywhere,” Leavitt said.

Leavitt and Under Secretary of State Paula Dobriansky recently completed a trip to Southeast Asia to meet with local officials and observe efforts there to combat the flu.

“Microbes know no borders,” Leavitt said, reporting that local governments were cooperative and eager to work on preventing the spread of flu.

Dobriansky said the U.S. government has committed $38 million to international efforts against the flu, including training veterinary staff, monitoring wild bird movements, setting up laboratories and helping foreign governments with training and preparedness plans.

When cases of bird flu are discovered, flocks such as chickens are destroyed, resulting in a loss to the small farmers who own the animals. Andrew Natsios, administrator of the Agency for International Development, said incentive plans are being set up to encourage farmers to report sick birds.

Leavitt said he had met with scientists in Vietnam working to develop a vaccine for the flu and offered U.S. help in setting up trials to test for effectiveness. Experiments on vaccines are underway in other countries also, but Leavitt noted that there is a worldwide shortage of vaccine manufacturing capacity.