COVID Could Be Transmissible From Animals to Humans and Vice Versa

Results from a Dutch scientific study may help prove that the coronavirus can travel between animals and humans.

The origin of the coronavirus has been a matter of question since the pandemic began. Initial reports claimed it began in a Chinese wet market where animals, such as pangolins and bats, were sold as food. While those claims were not proven, results from the Dutch study claim to provide the first proof that COVID-19 is transmissible between humans and animals.

Researchers studied 16 mink farms in the Netherlands, including 720,000 animals and 97 humans. "Due to longitudinal follow up of the first 4 farms, we have strong evidence that at least two people on those farms were infected by minks," the study read. "Unfortunately, based on our research we cannot make definite conclusions on the direction of most of the infections, so we do not know the total number of people that were infected by minks."

Among the study group, 67 percent of the humans developed the coronavirus. Samples of farm workers who tested positive for COVID-19 were genetically identical to samples taken from infected minks. Infected individuals who did not work on the mink farms provided samples that did not match those of infected farm workers.

"We conclude that at least some of these employees are very likely to have been infected directly from infected mink and thereby describe the first proven zoonotic transmission of SARS-CoV-2 to humans," the study said.

The study is expected to be presented at the European Society of Clinical Microbiology and Infectious Diseases conference on coronavirus in September.

Information on the Centers for Disease Control and Prevention (CDC) website said there was "no evidence" that animals are a major factor in the spread of the coronavirus. However, some animals have been shown to be carriers of the virus.

"We are aware of the findings from the Netherlands, and CDC guidance is up to date," the CDC said in a Monday statement to Newsweek. "At this time, there is no evidence that animals play a significant role in spreading the virus that causes COVID-19. Based on the limited information available to date, the risk of animals spreading COVID-19 to people is considered to be low."

In April, seven large cats at New York's Bronx Zoo tested positive for the coronavirus. "Our cats were infected by a staff person who was asymptomatically infected with the virus or before that person developed symptoms," the Bronx Zoo said in a statement at the time. All of the cats were expected to make a full recovery.

Dogs and cats kept as pets in over 10 states have also been diagnosed with COVID-19.

Initial reports about the virus originating at the Chinese market may be incorrect. In one potential scenario, humans shopping at the market may have given the infection to each other, causing the market to be the epicenter of a superspreader event. Since COVID-19 is a zoonotic infection, the virus could have traveled between humans and animals at the market. Some scientists have challenged that theory.

In May, Georgetown University professor Colin Carlson said tissue samples from animals at the Wuhan wet market did not carry any signs of the coronavirus. "I haven't seen anything that makes me feel, as a researcher who studies zoonotic disease, that this market is a likely option," Carlson said.

Updated 12:02 a.m. EST 9/22/2020: This story has been updated with a statement by the CDC.