(NewsNation) — At zoos across the nation, birds normally seen in outdoor habitats have been moved indoors and other precautions are in place as zoos wait out the latest avian influenza outbreak.

So far, there have been two confirmed cases of “bird flu” at two unnamed zoos across the country, but zoo authorities are worried that this highly contagious disease might spread quickly. Dr. Sathya Chinnadurai, senior vice president of animal health and welfare at Brookfield Zoo, near Chicago, said, “This year has been an incredibly bad year and probably one of the worst years for avian influenza.”

While poultry farms have dealt with the threat of bird flu with widespread euthanasia among their flocks, officials say that drastic measure is not necessary with zoo flocks. “We haven’t had any fatal cases in zoo birds yet, but we want to avoid that at all costs,” Chinnadurai said.

A lot of the protection includes isolating the rare and exotic birds at zoos from contact with wild migratory waterfowl, believed to be the biggest vector for spreading the disease. Dr. Luis Padilla, vice president of animal collections with the St. Louis Zoo, said, “We have closed our bird-house to public access. And we have closed our flight cage to public access as well. Unknowing and unwilling persons could have tracked avian influenza in their shoes, where birds could be at risk.”

Patrick Riley, with the Seneca Park Zoo in Rochester, N.Y., said if you want to visit the birds, you’ll have to clean your feet. “Foot baths, for anybody who is going into the bird habitat, to just make sure we are very clean and to make sure we are not carrying the virus, when go into the birds.”

Chinnadurai said the birds most at risk from the flu are guinea fowl, peacocks and peahens, the birds most closely related to chickens and turkeys. All birds can carry it, however, even penguins, and there is no vaccine approved yet in the U.S.

“Some birds can carry it and shed it and now carry clinical signs and other birds can carry it and become rapidly ill and can die from it,” Chinnadurai said.

For now, zoo officials are hoping the disease runs its course and dies out in the next month or so, allowing them to open their exhibits. They also stress that there is no danger to humans from the disease.