[Animals]Animals Can Get Covid-19, Too. Without Government Action, That Could Make the Coronavirus Harder to Control

[FRIDAY THE 13]

When several tigers and African lions at the Bronx Zoo tested positive for the coronavirus last April, Tracey McNamara was not surprised.

The big cats fell ill a little more than a month after New York City reported its first Covid-19 case. But McNamara, a veterinary pathologist at Western University of Health Sciences in Pomona, California, knew as early as January 2020 that zoo animals might be at risk: A senior Chinese health official had warned the public that the virus spread between mammals and that they should quarantine any pets that might have encountered an infected person.

Soon after the virus infected the zoo’s felids, Chinese scientists reported in the journal Science that cats were “highly susceptible” to the coronavirus. SARS-CoV-2 (short for severe acute respiratory syndrome coronavirus 2), the virus that causes Covid-19, “can replicate efficiently in cats,” the authors wrote. And, perhaps more importantly, they noted, the virus can transmit “between cats via the airborne route.”

The pandemic has claimed more than 2 million human lives worldwide, more than 418,000 of them in the United States, even as governments spend billions to contain it. And now an expanding list of species have contracted Covid-19, including lions, tigers and gorillas in zoos, mink on farms and in the wild, and pet dogs and cats. Studies show that other animals can be infected in the lab, including ferrets, hamsters, rabbits, mice, monkeys and raccoon dogs.

Scientists like McNamara say there’s an increasingly urgent need to figure out which animals can not only contract but also transmit the virus. It’s clear that small carnivores like mink, raccoon dogs and cats do so, though so far only mink have infected people. But if enough animals become reservoirs of infection, and allow the virus to move easily between animals and people, it will be much harder to control the pandemic. 

Dedicated efforts to monitor captive and wild animals that could be susceptible are essential, said Christine Kreuder Johnson, director of the EpiCenter for Disease Dynamics at the University of California, Davis One Health Institute. Otherwise, they could become sources of transmission after the outbreak is controlled in people.

Over the past few decades, international health agencies have recognized that controlling infectious diseases requires focusing on the interconnections between people, animals and their environment. With this “One Health” approach, explained Ann Hohenhaus, staff veterinarian and hospital spokesperson for the Animal Medical Center in New York City, “if you have a problem in one, you’re going to cause problems in the others.” 

The novel coronavirus revealed the folly of ignoring a One Health approach, Johnson and her colleagues argued in a commentary published in Health Affairs last week, calling the U.S. response “unprepared, overconfident and inept.” They urged the incoming Biden administration to create an interagency One Health task force to improve U.S. pandemic preparedness by forging domestic and global collaborations that target “key drivers of disease emergence, including climate and global environmental changes.”

It’s a massive undertaking. But with zoonoses—pathogenic diseases that spill over from animals to humans—accounting for three-quarters of emerging infectious diseases, it’s one that public health officials cannot afford to ignore. At the least, it will require better coordination between public and animal health agencies. Ideally, McNamara and others say, it would involve launching a comprehensive animal and environmental health surveillance network.

McNamara has urged public health officials to do both ever since the West Nile virus caused scores of crows to drop dead around the grounds of the Bronx Zoo more than two decades ago, when she was the zoo’s lead pathologist.

In the summer of 1999, McNamara feared she was seeing something new to veterinary medicine when wild crows, and then flamingos and other birds at the zoo, started keeling over. Around the same time, city health officials reported an unusual cluster of cases and deaths associated with a strange encephalitis, or brain inflammation, after a record-breaking heatwave and torrential rains—perfect breeding conditions for mosquitoes. McNamara’s gut told her the animal and human illnesses were linked. She shared her concerns with the Centers for Disease Control and Prevention, but officials there told her they saw no connection between dying New Yorkers and birds. The CDC dealt with human health, she was told, not flamingos. That “jurisdictional straitjacket,” she argued in a 2018 Ted talk, blinded officials to a novel public health threat. 

It took several weeks and misdiagnoses at state and federal labs before scientists finally identified the culprit as West Nile, a mosquito-borne disease previously unknown in the Western Hemisphere. The bungled approach to the outbreak inspired a congressional report on lessons for public health preparedness. The report stressed recognizing that many emerging diseases affect both animals and people, and the importance of bolstering the links between public and animal health agencies to prevent future spillovers.

More than two decades later, however, nothing has changed, McNamara said, even though yawning gaps in surveillance have opened the door to several new deadly viruses. And even though SARS-CoV-2, like West Nile, jumped from animals to people, she added, “all anybody wanted to look at was people.”

All the species in closest contact with humans in crowded urban centers—dogs, cats, zoo species, shelter animals, non-game wildlife—still do not fall under the jurisdiction of any federal agency and are not under surveillance, she said.  

So instead of catching potential threats to human health in animals, she added, “the only time we find stuff is when we have dead people.”

 

To find out more
 

https://insideclimatenews.org/news/27012021/animals-covid-19-control/