Tuberculosis is killing this zoo's lemurs—but it hasn't closed

Visitors have been photographed holding animals at the Madagascar zoo. Its lemurs likely caught the disease from humans.

A tuberculosis outbreak at a Madagascar zoo has killed critically endangered primates, including species of lemurs never known to have had the disease.

In recent weeks, eight black-and-white ruffed lemurs, one sifaka, and one fossa have died at the government-run Tsimbazaza Zoo and Botanical Park (PBZT), in Antananarivo, Madagascar’s capital, all from presumed cases of the disease. Scientists from the Institut Pasteur of Madagascar, supported by members of the International Union for Conservation of Nature, have confirmed the presence of Mycobacterium tuberculosis (tuberculosis) in the tissues of several of the dead animals.

The zoo, which houses several hundred animals and remains open to visitors, should be closed immediately, according to Jonah Ratsimbazafy, a Malagasy primatologist.

The zoo did not respond to requests for comment.

Human handlers or visitors likely transmitted the disease, which has never been found in lemurs in the wild, Ratsimbazafy says. Tuberculosis is widespread in people in Madagascar, and in 2019, a pet ring-tailed lemur was found to be infected.

Tsimbazaza zoo has about a dozen species of lemurs, and the outbreak involves the first documented incidence in black-and-white ruffed lemurs, sifaka, and fossa, Ratsimbazafy says. The IUCN lists ruffed lemurs and sifaka as critically endangered, and fossa as vulnerable to extinction.

“It is not known if these animals can transmit the disease to one another or to humans,” Ratsimbazafy says. “We know that humans can transmit TB to lemurs and suspect that the animals acquired tuberculosis from humans that they are—or have been—in close contact with.”

National Geographic Explorer Marni LaFleur, an anthropologist at the University of San Diego, in California, who studies the species, was part of the team that reported the disease in the pet lemur in a paper last year. She says visitors to the zoo routinely post photos on Instagram that show them holding and feeding lemurs.

Ratsimbazafy says that unless the zoo is closed, staff and animals could transmit tuberculosis to visitors. The zoo lacks the capacity to control this highly contagious disease, he says, and must work with domestic and international veterinary and medical experts to halt its spread.

“Containing the spread of tuberculosis at PBZT will likely require animal euthanasia,” Ratsimbazafy says. He recommends strongly against capturing lemures from the wild to replenish animals that may be euthanized or have already died.

Madagascar has more than a hundred species of lemurs, representing about 20 percent of the world’s primates.

The National Geographic Society supports Wildlife Watch, our investigative reporting project focused on wildlife crime and exploitation. Read more Wildlife Watch stories here, and send tips, feedback, and story ideas to NGP.WildlifeWatch@natgeo.com. Learn about the National Geographic Society’s nonprofit mission at natgeo.com/impact.

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