A rabid anteater was moved from one zoo to another, leading to rabies treatment for 13 people

The transport of an anteater from one zoo to another may have exposed more than a dozen people to rabies, researchers said Thursday, serving as a warning that such transfers can expand what are considered “rabies zones.”

Thirteen people had to undergo rabies treatment for possible exposure, and no human cases were ultimately reported, according to the report, published Thursday in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.

Rabies, which is almost universally fatal if untreated, is sometimes underestimated as a threat, recent research suggests. A CDC report from earlier this year described the cases of three people who died from rabies contracted from bats, all whom could have survived had they sought or accepted post-exposure care.

Available treatments work very well when given early. Typically, three people or fewer die from rabies in the United States each year.

Earlier this month, a rabid fox bit at least nine people on Capitol Hill before being euthanized; those who had to be treated included a member of Congress.

The new report, by researchers from the CDC and in Tennessee, describes what happened when a South American collared anteater — also known as a tamandua — was moved in May 2021 from a zoo in Virginia to one in Washington County, Tenn.

The month after the anteater arrived in Tennessee, it started showing signs of lethargy and wasn’t eating. It kept getting sicker, but veterinarians didn’t consider the possibility of rabies in part because it had never previously been identified in the species. The anteater was euthanized on July 6.

It was only six weeks later that the death investigation found that the animal could have died from rabies, which additional tests confirmed. The investigation had not been expedited because rabies had not been suspected.

State health authorities were then notified, and set out to identify people who were possibly exposed, from people who were around the anteater two weeks before it started showing symptoms to those who worked on the necropsy. Ultimately, they recommended treatment for 13 people, seven of whom came into contact or may have had contact with the animal’s tongue and saliva. (These animals don’t have teeth, so there was no risk of bites.) The other six were involved with removing the animal’s brain during the necropsy. All 13 people agreed to receive the treatment, and no human cases were reported.

The treatment for someone who may have been exposed to rabies — what’s called post-exposure prophylaxis — includes a dose of human rabies immune globulin and several doses of the rabies vaccine given over two weeks. The immune globulin provides an immediate supply of antibodies, while the vaccine prompts people to generate their own antibodies.

There was also the question of how the anteater got rabies. At the Tennessee zoo, it was kept in an indoor enclosure with one other tamandua and didn’t have exposure to other wildlife. But at the Virginia zoo, it was in an open-air exhibit. Tests found that the rabies virus that infected the anteater was most similar to variants found among wild raccoons in Virginia — suggesting the anteater was infected in Virginia.

The other tamandua in Tennessee was given the rabies vaccine, and the zoo was told to quarantine it for six months. As of April 1, no other cases of rabies tied to the anteater have been identified in Virginia or Tennessee.

The researchers said the case also underscores how crucial it is for animal handlers and zoo animals to be vaccinated against rabies in areas where the virus is present.