U.S. wild deer will have new crown antibodies in 2019. What does this mean?
According to foreign media reports, in a recently released retrospective study, researchers from the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) said that the new crown was found in blood samples collected from a wild white-tailed deer herd in the United States in 2019. Traces of virus antibodies.
However, the USDA denied this, saying it was "almost certainly a false positive." what on earth is it?
▲Wild white-tailed deer. According to the US "Staten Herald" ▲Wild white-tailed deer. According to the US "Stanton Herald"
2019 samples tested positive for new crown antibodies
What does this mean?
It is reported that researchers from the United States Department of Agriculture (USDA) conducted antibody analysis of the new coronavirus on more than 600 wild white-tailed deer blood samples from Michigan, Illinois, New York and Pennsylvania. It was found that a total of one-third of the white-tailed deer sampled had antibodies related to the new coronavirus, and antibodies were detected in up to 60% of the samples in Michigan.
On July 29th, researchers from the Animal and Plant Health Inspection Service (APHIS) of the United States Department of Agriculture published a related paper on the bioRxiv platform in the form of a preprint, "Research on Wild White-tailed Deer Infection with New Coronavirus". According to the article, the researchers analyzed blood samples of white-tailed deer collected between 2011 and 2021. The analysis results showed that of the 385 blood samples collected from January to March 2021, 40% of the new coronavirus-related antibodies can be detected.
▲Related paper "Research on New Coronavirus Infection in Wild Whitetail Deer" published by APHIS researchers. The screenshot is taken from the related paper "Research on Wild White-tailed Deer Infected with New Coronavirus" published by APHIS researchers on the bioRxiv platform. Screenshot from the bioRxiv platform
It is worth noting that further testing found that in the 239 samples collected before January 2020, the presence of positive antibodies to the new coronavirus was also found. Among them, related antibodies were detected in 3 of the samples collected in early 2020, and related antibodies were detected in 1 of the samples collected in 2019. No antibodies were found in the samples from 2011 to 2018.
So, the positive result of this case in 2019 means that the emergence of the new crown virus in the wild animals in the United States has been advanced to 2019?
The researchers further explained in the paper that the inhibition rate of most positive samples in 2021 is 80%~100%, while the inhibition rate of positive samples in 2019 and 2020 is relatively low, only 30.03%~43.72%. Generally speaking, if the inhibition rate is greater than 30%, it will be considered positive. However, the lower inhibition rate may be interfered by other factors, such as potential immune enhancement or weakening, non-specific antibody binding, or detection of cross-reactions caused by other coronavirus antibodies.
Schematic diagram of the test results of serum samples from wild white-tailed deer in the United States. According to bioRxiv
The U.S. Department of Agriculture is inconsistent
American experts believe that cross-infection cannot be ruled out
However, according to US media reports, the USDA directly denied this possibility, saying that it was "almost certainly a false positive" because of its very low antibody level. This is slightly contradictory to the previous statement that "very confident in the test results".
According to US media reports, the USDA previously stated in a statement that all testing procedures have taken reasonable precautions to ensure the accuracy of the data. The researchers also used two different machines for antibody testing to ensure the accuracy of their conclusions. Therefore, the relevant data results show that the new crown antibody has been quite common in the deer herd, and a large number of deer are likely to have been infected with the new crown virus.
▲U.S. media reported that 67% of wild white-tailed deer in Michigan have antibodies to the new coronavirus. According to WILX▲ US media reports, 67% of wild white-tailed deer in Michigan have antibodies to the new coronavirus. Figure according to WILX
In addition, the U.S. Department of Agriculture also stated to National Geographic magazine in a statement that “the results of the second test reflect the findings of the first test, that is, the new crown antibody was indeed detected.”
The National Geographic of the United States further analyzed that if antibodies to other coronaviruses are detected, then the blood samples of white-tailed deer collected before and during the outbreak of the new crown epidemic should have similar levels of antibodies in their bodies, but in 239 samples Only 1 case was positive, indicating that there was no cross-infection.
However, Daniel Bowsch, head of emerging threats and global health and security for the non-profit organization FIND, believes that although the two tests gave him confidence in the results of this study, the possibility of cross-reactions cannot be completely ruled out, because there may be many that have not yet been tested. The discovered coronavirus spreads among animals.
The path of deer infection remains a mystery
The state where the German Fort is located suddenly stopped deer sampling
In addition, there is another question that has attracted the attention of researchers: How did these white-tailed deer get infected?
US media reports pointed out that although researchers suspected that the wild deer herd was infected by humans, they did not have any definite conclusions on the route of infection. In their paper, they listed several potential transmission routes for the new crown virus to enter the wild deer herd: one is contact with humans (infection), including captive deer, field research, conservation work, wildlife tourism, wildlife rehabilitation, supplementary feeding and hunting A variety of activities are possible to achieve transmission; and other potential transmission methods, including through contaminated water sources or contact with other infected species.
▲Wild white-tailed deer in Henlopon Point State Park, Delaware, USA. According to Agence France-Presse ▲Wild white-tailed deer in Henlopon Point State Park, Delaware, USA. According to Agence France-Presse
According to a previous report by the People’s Daily, it is worth noting that, according to the news on the official website of the National Deer Association of the United States on July 14, due to the impact of the new crown virus, Maryland and West Virginia completely stopped hunting deer in the fall of 2020. Sampling test work for "chronic wasting disease".
Coincidentally, the US Army Fort Detrick Biological Laboratory is located in Maryland, not far from West Virginia. According to previous reports in the US media, in July 2019, Fort Detrick's Biological Laboratory was temporarily closed “due to a failure of the wastewater purification system”.
According to the website of Time News, a local media outlet in Cumberland, western Maryland, the halt of sampling in the fall of 2020 was the first time that sampling was halted since 2010 when a "chronic wasting disease" was first discovered in a herd of Maryland deer. Test work. A spokesperson for the Maryland Department of Natural Resources said in an email: "This is to prevent the spread of the new crown virus and protect the safety of workers and the public."