BROOKFIELD, IL — The reported infection of animals with COVID-19 has been documented around the world. Most have been infected after contact with their human owners or caretakers.

Veterinarians say part of the fight against the coronavirus includes vaccinating zoo animals to prevent what’s known as spillover infections.

Scientists say most emerging infectious diseases originate in animals.

In fact, the zoonotic origin of the 2003 SARS outbreak in Asia was traced back to cave-dwelling horseshoe bats in China. It eventually reached animals in live markets where it spilled over into humans.

“There's a huge interconnectedness between animals and people when it comes to a different number of different viruses and other illnesses,” said Dr. Mike Adkesson, vice president of clinical medicine at the Chicago Zoological Society

Still, the source of SARS-CoV-2 or COVID-19 is still an official mystery.

An unclassified report from the office of the Director of National Intelligence last month was only confident that it was “not developed as a biological weapon.”

What we do know is that the novel coronavirus is not a human-only infection.

“We have seen cases of COVID-19 occur in a number of different species around the country in different zoos, primarily primates, large cats such as tigers, lions, leopards, as well as a number of smaller carnivores like otters and mink,” said Adkesson.

Late last week, more than a dozen western lowland gorillas reportedly tested positive for COVID-19 at Zoo Atlanta. Their care team noticed changes in appetitive and respiratory issues.

“Coughing, sneezing, lethargy, the animals just clearly feel a little bit under the weather, the same way that we see those same signs and symptoms in people,” said Adkesson.

While animals are not playing a major part in the transmission of the virus, they are clearly susceptible.

“Part of the concern is that those animals are able to spread it to other animals and potentially able to spread it back to people,” said Adkesson.

The CDC says there have been isolated cases of domestic dogs and cats that have become infected and have been able to transmit COVID-19 back to people.

Zoos across the country are now vaccinating their animals beginning with carnivores, primates, and big cats. The emergency use authorization of the vaccine Zoetis requires two doses three weeks apart.

“We're still pretty early on in this process, but we know that the vaccine is safe from the trials that Zoetis has done with it,” said Adkesson. “So, it's really just a question of how efficacious it's going to be in the long run for our animals.”

Caretakers at the Brookfield Zoo outside Chicago have been required to mask and maintain social distancing as much as possible from the animals.

“There have been cases that have emerged in other zoos, though, even with those guidelines in place. So, we know that the virus is able to infect many of these animals the same way it's able to infect people,” said Adkesson.

It’s another reminder that the health of humans, animals, and the environment is intertwined.

With misinformation lurking around nearly every corner of the internet, researchers across the country are working to rehab the image of bats in the face of the COVID-19 pandemic.

Barry Genzlinger runs the Vermont Bat Center and has been rehabbing bats for about a decade.

"Bats are nature's absolute best pest controller for nighttime pests," he explained.

While he has a personal love for bats, Genzlinger understands why not everyone loves these mammals.

"Hollywood has convinced us that bats are scary, evil, they attack humans. When in reality, they are just the cutest darn thing," Genzlinger said.

Genzlinger's goal these days is to keep bats from catching coronavirus. Every single bat he rehabilitated this winter got a nose swab, just like us humans.

Researchers across the country are doing similar testing. Those swabs are then sent to Tufts University to be analyzed. So far, none of Genzlinger’s bats have tested positive for the virus. But the concern is that if one bat has COVID-19, it could infect an entire colony.

"It’s not so much that people in North America are concerned about getting COVID from our bats, it’s the other way around. We are concerned about giving COVID to bats that have never been exposed to it," he said.

COVID-19 has not done the image of bats any favors. The origin of the virus is not confirmed, but some studies indicate it originated from similar viruses found in bats in the Eastern Hemisphere.

In an effort to rehab the image of bats during this pandemic, scientists like Sarah Strew have been hosting a series of online clinics. The goal is to remind folks and educate them about the good bats do for the environment.

"There just had been so much misinformation at the beginning of everything," said Strew.

Strew oversees programs at the Vermont Institute of Natural Science.

"We felt it was important and a way to peak people’s interests because it is something relevant to their lives right now. We’re all going through this together," she added.

There are an estimated 1,300 bat species worldwide, 47 of those species are located in the United States. Many species though are considered endangered because of disease, hunting or their habitats have been destroyed.

So far, evidence suggests that the risk is low that scientists could pass coronavirus to North American bats. But researchers across the country aren't taking any chances and are taking extra precautions to keep bats safe.

"The biggest takeaway is that we as humans are not separate from the natural world," Strew said.

It’s all in an effort to keep the sun from setting on this nation’s population of bats.