Chimp dies: Mystery ailment strikes Lincoln Park zoo chimps

March 27, 2009

Lincoln Park Zoo officials are watching six ailing, quarantined chimpanzees around the clock after an adolescent member of the group died in the zoo's hospital earlier this week.

The 9-year-old chimp, a male named Kipper, died Tuesday, a day after veterinarians brought him to the zoo hospital. He and the other six members of his group, who are usually on exhibit in the Regenstein Center for African Apes, came down with a mysterious upper respiratory infection March 19.

The cause of the respiratory ailment is still unknown, and there is no indication that it has spread to the ape house's other chimp group or to its two gorilla families, said Steve Thompson, the zoo's vice president of conservation programs.

The initial necropsy reports listed pneumonia as the cause of Kipper's death, according to Thompson. The youngest member of his group, Kipper had a congenital condition that may have limited his breathing capacity, causing more serious problems for him than for the others, Thompson said.

Great apes like chimpanzees and gorillas suffer from the same sorts of respiratory diseases as humans, so zoos have been instituting increasingly more rigid protocols to limit direct contact between humans and apes. Even on a normal day at Lincoln Park Zoo, any human coming into contact with the apes is required to wear sterile masks, clothing and footwear.

It's possible the apes could contract disease from wild animals that occasionally get into their outdoor habitats, such as squirrels and birds, Thompson said, adding that it may be impossible to learn how the chimpanzees were infected.

With the initial symptoms in the chimpanzee group persisting over the weekend, the zoo took the seven chimps off display and put them in quarantine quarters in the lower level of the ape house.

The facility has no true isolation ward, but ill and healthy animals are kept on opposite sides of the building and keepers do a complete clothing change when moving between groups.

After going into isolation with his group, which is headed by a male named Hank, Kipper took a turn for the worse on Monday, showing pneumonia-like symptoms, Thompson said.

"He was sounding like he had trouble breathing, and he hadn't eaten or drunk much," Thompson said. "He was taken to the zoo hospital, where the vets sedated him to treat with fluids and put him on antibiotics.

"He was under round-the-clock observation and early Tuesday seemed improved. He was moving around and knew his surroundings, recognized his keepers and the vets. But at some point he was left alone for 15 to 20 minutes, and when somebody checked on him, he had stopped breathing and couldn't be revived."

Kipper was born with a concave sternum on the left side of his chest that reduced the size of his chest cavity and may have impeded his lungs from expanding fully, perhaps putting him at a disadvantage in fighting off the infection, Thompson said.

"This is the kind of pneumonia condition that is difficult to treat in humans and non-human primates," he said.

Thompson said the other six chimpanzees in the group are not as ill as Kipper was, but they also have not recovered, so the zoo has them under around-the-clock monitoring in quarantine.

"Unfortunately they can't tell us how they feel, so we are trying every possible precaution," he said. "Some seem to be well on the way to recovery; others still have a serious respiratory condition, so we are watching them very closely, with antibiotic treatments."

None of the other apes in the building has shown any symptoms of the disease, he said.

The ape house remains open and its gorillas are on public view, but the habitat usually occupied by Hank's group is empty. The zoo's second chimp group remains in the off-viewing quarters where it normally lives.

Courtesy of Richard Reynolds