A Rare Bacterium Killed Three Point Defiance Puffins. Here’s What Officials Know

Investigators have identified a rare bacterial infection as the likely cause of three tufted puffin deaths at Point Defiance Zoo & Aquarium earlier this summer—but they still do not know how it entered the birds’ habitat.

Preliminary testing in July had pointed to avian psittacosis, an illness caused by Chlamydia psittaci. Additional laboratory work has now identified a related but considerably less common avian strain of Chlamydia abortus in the three puffins, according to the Tacoma-Pierce County Health Department.

Despite the unusual finding, officials say there are several reassuring signs. No additional infected birds have been identified, environmental samples taken inside the habitat in early August did not detect the bacteria and no associated human illnesses have been reported. Public-health officials continue to describe the risk to zoo visitors and the wider community as low.

The puffin habitat remains closed while the remaining colony is monitored and additional testing is completed. The rest of Point Defiance Zoo and the surrounding park remain open.

Exactly how the bacteria reached the puffins has not been determined. Exposure to a wild bird is one possibility under investigation. Agencies conducted expanded environmental sampling around the zoo and Point Defiance Park in September, while healthy birds from the habitat and an interior exhibit underwent additional testing.

Visitors may encounter wildlife and health personnel wearing masks and gloves while gathering samples. Officials emphasize that the protective equipment is intended for employees handling bird droppings and other potentially contaminated material—not because the park is considered unsafe for visitors.

The investigation involves the zoo, Tacoma-Pierce County Health Department, Washington State Department of Health, Washington Department of Fish and Wildlife, Washington State Department of Agriculture and the Centers for Disease Control and Prevention. Samples are also being examined by the University of Georgia’s Infectious Diseases Laboratory.

For now, the newest testing answers the largest question surrounding the three deaths, but not every one. Zoo officials have not announced when the puffin habitat might reopen, saying it will remain closed until they are confident it is safe for the surviving birds and the public.

See the health department news release here.