The Maricopa County Department of Public Health is working with state and federal officials to respond to the detection of avian influenza in a “small number of animals” that are part of a zoo collection in Litchfield Park, authorities said Wednesday.

“Overall, risk to the public and zoo visitors remains low,” a release from the county agency stated.

The Wildlife World Zoo identified ill animals and brought them into the Arizona Department of Agriculture to conduct testing. Test results indicated that the animals were likely ill from H5N1 avian flu, which was first seen in wild birds in the United States in 2015, according to the release.

MCDPH is working with the zoo to identify and contact staff and volunteers who are considered to be at higher risk from close, prolonged contact with the infected animals.

“People who have job-related exposures to infected animals, especially close prolonged exposure, are at higher risk of infection,” Dr. Nick Staab, assistant medical director at MCDPH, said.

“Public health’s recommendations are intended to reduce the risk to those who have had direct contact with infected animals and to prevent further exposure.”

Kristy Hayden, president of Wildlife World Zoo, said "while we are deeply saddened to report the loss of a few cherished animals, we are grateful that the impact was limited thanks to our swift response, robust biosecurity protocols and the invaluable support of Maricopa County Department of Public Health and state and federal agencies.”

Avian influenza H5 is a novel influenza A virus that primarily affects birds. It has recently been detected in Arizona, including a commercial poultry farm in Pinal County and a backyard flock in Maricopa County, officials said.