A new study of white-tailed deer claims that more than 80 percent of white-tailed deer test positive for COVID-19. After comparing the viral lineages, scientists found that the infection of the white-tailed deer most likely came from contact with the population. At present, the white-tailed deer has not shown any typical symptoms due to infection, but such a high proportion of infection has made the white-tailed deer a "virus savings pool", which has a great tendency to tire eggs.
The study was led by the research team at Penn State University, led by Suresh V. Kuchipudi, a professor of biomedicine and deputy director of pennsylvania State's Animal Diagnostic Laboratory. The researchers sampled white-tailed deer in different parts of Iowa, USA, between December 2020 and January 2021, and the results showed that more than 80 percent of white-tailed deer tested positive for SARS-CoV-2. It is also because of the data from this study that the percentage of COVID-19 infections in all deer populations has been pulled up to 33%. The researchers said that white-tailed deer should be taken seriously as a potential host for the spread of the new coronavirus, and they may develop new strains of the virus in the population.
Earlier this year, the U.S. Department of Agriculture tested 385 white-tailed deer blood samples collected in Michigan, Pennsylvania, Illinois, and New York between January and March 2021, and 40 percent of the samples tested antibodies related to the new coronavirus. However, the deer surveyed showed no signs of illness. Kuchipudi and colleagues point out that the presence of antibodies in the sample only indicates that the deer herd has been exposed to the new crown virus or other immunologically linked organisms, and does not confirm that the deer herd is infected with the new crown or has the ability to continue to spread the virus. And this study really confirms this.
The study was published on the preprint platform bioRxiv on Nov. 1 and is also being prepared for publication in peer-reviewed journals. Between December 2020 and January 2021, at the height of the local COVID-19 pandemic, researchers took samples from the posterior pharyngeal lymph nodes in deer necks and examined the coronavirus RNA in the samples by real-time reverse transcription-polymerase chain reaction (RT-PCR), which will provide direct evidence for whether they are infected with the new crown virus.
Kuchipudi said, "We found that 80% of the deer sampled in December tested positive for COVID-19, a 50-fold increase from the peak of human infection, and between April and December 2020, the number of COVID-19 positive deer gradually climbed, with the largest increase occurring during last year's golden deer hunting season." The overwhelming amount of evidence points to the fact that infections in deer herds are caused by epidemics in populations.
To test this judgment, the researchers also sequenced the complete genome of deer samples infected with covid-19 and identified 12 new coronavirus lineages, of which the pedigrees B.1.2 and B.1.311 accounted for about 75% of all samples.
Vivek Kapur, Chair Professor of Microbiology at Penn State University, noted, "The viral lineage we identified corresponds to the lineage that spread through the population at the time. The fact that we found that several different strains of COVID-19 spread throughout the state in herds with limited geographic extent suggests that there have been many independent transmission processes from humans to deer herds before "deer-to-deer transmission" between deer herds takes place on a large scale. This also increases the likelihood of re-infection of humans from deer herds, especially in remote suburban areas with high deer densities. ”
Kuchipudi said: "The infection of white-tailed deer is the first direct evidence of infection with the new crown virus in non-captive wild species. Our findings have important implications for studying the ecology and long-term prevalence of the virus – does the virus spread to other wild animals through deer herds, or to captive animals, or even to human hosts? ”
Kuchipudi emphasizes: "The findings demonstrate that there is an urgent need to implement surveillance programmes to monitor the spread of COVID-19 in deer herds and other susceptible wildlife species and to take appropriate measures to prevent potential virus transmission. Kapur also cautioned: "Although there is currently no evidence that COVID-19 can be transmitted from deer herds to humans, it is still recommended that deer hunters and people living close to the deer herd take appropriate precautions, including wearing appropriate protective equipment and getting vaccinated against COVID-19 during contact with animals." ”
In late April 2020, there was an outbreak of COVID-19 at two mink farms in the Netherlands. In response to outbreaks in mink farms, the Netherlands has launched a national zoonotic response system. From 20 May 2020, the Dutch government imposed an obligation on mink farmers, veterinarians and laboratories to report symptoms of mink to the Dutch Food and Consumer Product Safety Agency and established an extensive surveillance system. Research from the WHO Collaborating Centre for Reference and Research on Viral Insect Diseases and Viral Haemorrhagic Fevers has demonstrated that the outbreak was transmitted from humans to farmed mink, followed by widespread transmission between mink and eventually re-infection of humans. This is also the first time that the phenomenon of alternating transmission between humans and animals of the new crown has been found.
With the lessons of mink, no one can guarantee whether the menacing white-tailed deer new crown epidemic will become the next source of chaos.