Title: Analysis Reveals Americans Transmitting COVID-19 to Wild Deer, Mutated Variants Spreading
Date: July 11, 2023
Author: Alexander Tin
Source: CBS News
A recent analysis of thousands of samples collected from wild deer suggests that Americans have transmitted COVID-19 to these animals hundreds of times. Furthermore, mutated variants of the virus have been caught and spread from deer back to humans at least three times, according to the study published on Monday.
The analysis is part of a multiyear federal effort led by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) to study the spread of the virus into American wildlife. Scientists examined 8,830 samples collected from wild white-tailed deer across 26 states and Washington, D.C., between November 2021 and April 2022. Out of these samples, 282 deer were found to be infected with COVID variants.
By comparing the virus sequences in deer with publicly reported samples from human infections worldwide, researchers were able to trace the likely spread of these variants between humans and animals. They identified a total of 109 “independent spillover events,” linking viruses found in deer to their likely predecessors in previously infected humans.
Several of these variants, including the Alpha, Gamma, and Delta variants, are still mutating and spreading among deer. These variants were responsible for an increase in deaths earlier in the pandemic, even after the emergence of the Omicron variants that currently dominate nationwide.
Interestingly, 18 of the samples had no genetically close human SARS-CoV-2 sequences within the same state, making it difficult to track down the precursor variant in humans.
The study’s authors concluded that frequent introductions of new human viruses into free-ranging white-tailed deer continue to occur, and SARS-CoV-2 variants of concern can persist in deer even after becoming rare in the human population.
Three variants with distinctive patterns of spillover from humans to deer and then back to humans, known as “spillback,” were identified. Two of these spillback variants were found in North Carolina, and one was found in Massachusetts. An investigation conducted by the Centers for Disease Control and Prevention (CDC) successfully traced three infected individuals and a few zoo lions who were infected by the same strain with the hallmark deer mutation. None of the humans reported close contact with deer or the zoo.
Researchers from APHIS have been studying whether white-tailed deer, among other American wildlife species, could serve as long-term reservoirs for the virus, allowing it to mutate and spread among deer. A previous report from Canadian scientists found a highly divergent lineage of SARS-CoV-2 that spread from deer to humans.
Government scientists are concerned about the potential impact of the virus on animals as it spreads between humans and wildlife. Deer regularly interact with humans and are commonly found in human environments, such as near homes, pets, wastewater, and trash, according to University of Missouri Professor Xiu-Feng Wan, one of the authors of the study.
The authors of the study also highlighted other instances of diseases spreading between humans and deer, such as a previous outbreak of bovine tuberculosis among deer in Michigan linked to local supplemental feeding efforts to support wild deer populations.
The CDC has previously advised Americans to avoid close contact with wildlife and their droppings to minimize the spread of not only SARS-CoV-2 but also other zoonotic diseases that can spread between humans and animals.
“The potential for SARS-CoV-2, or any zoonotic disease, to persist and evolve in wildlife populations can pose unique public health risks,” warned Wan.
As the study sheds light on the transmission of COVID-19 between humans and wildlife, it underscores the importance of continued vigilance and preventive measures to mitigate the risks associated with zoonotic diseases.
What measures can be taken in areas with close contact between humans and wild deer to minimize the risk of transmission and prevent the spread of mutated variants
To have infected individuals in the same geographic region where the infected deer were found, indicating localized transmission.
The implications of these findings are significant as they suggest that humans can not only transmit COVID-19 to wildlife, but they can also become infected with mutated variants that have originated in animals. This highlights the importance of monitoring the spread of the virus in both human and animal populations to prevent the emergence of new variants that could potentially pose a threat to public health.
The study also raises concerns about the potential for ongoing transmission between humans and wildlife, particularly in areas where there is close contact between humans and wild deer. Wildlife management strategies and public health measures may need to be implemented to minimize the risk of transmission and prevent the spread of mutated variants.
Overall, this analysis provides further evidence of the complex and dynamic nature of the COVID-19 pandemic, and the need for continued surveillance and research to understand and mitigate its impact on both human and animal populations.
This fascinating study sheds light on an unexpected aspect of COVID-19 transmission. It raises questions about the role of wildlife in the spread of the virus and highlights the need for further research in this area.