As millions of chickens are slaughtered in Asia in an attempt to stop the spread of avian flu, Illinois officials are monitoring the outbreak and preparing to react.

The Illinois Department of Agriculture instituted new regulations Sunday, requiring all imported livestock, including poultry, to be registered prior to arrival in Illinois.

Livestock importers previously were required to register importation of livestock within 30 days, said Jeff Squibb, spokesman for the Illinois Department of Agriculture.

The new measure requires importers to notify the department within a 72-hour period before bringing the animals in.

The World Health Organization reported Monday that the avian flu strain known as H5N1 has infected at least 14 people in Vietnam and Thailand. Eleven of those people have died.

WHO investigators are studying whether the case of two sisters in Vietnam could be the first known transmission of the virus from human to human.

The sisters may have been infected when they cared for their ill brother in January, according to WHO.

If the virus mutates and acquires DNA from human strains of influenza, the world may see another influenza pandemic, according to the Centers for Disease Control and Prevention.

The disease is thought to spread to humans through contact with infected animals and their feces, according to WHO. The organization stated it does not think the disease can be spread through eating chicken or eggs.

Because H5N1 does not commonly infect humans, the population would not have developed any immunity to the hybrid virus, according to the CDC.

Illinois officials began discussing the new measure last fall in response to the danger of foreign diseases – including avian flu – entering the U.S. food supply.

With the livestock information gathered, the state would be able to pinpoint quickly which region the animal came from and where it went, Squibb said. It would allow prompt reaction and containment of any exotic disease, he said.

Efforts to contain the disease in Asia have centered on culling at-risk chicken populations.

Massive slaughter of poultry in the region likely will raise market prices for eggs and chicken, said Richard Lobb, spokesman for the National Chicken Council.

“It’s hard to say exactly how it will turn out,” Lobb said. Thailand is a major exporter with customers in Japan and the European Union, so they’re looking for other suppliers, he added.

Some American producers have received inquiries into their products. With increased demand, egg and poultry prices could increase, but Lobb said he does not see the disease impacting American markets dramatically.

The CDC is developing a vaccine for the virus, but does not know when the vaccine could be completed or how effective it may be, Pearson said. The organization also has sent six staff members to Vietnam to assist in efforts to corral the virus.

– The Associated Press contributed to this report