Stunning Report: 20% of Zoo Animals Test Positive for SARS-CoV-2 After Human Exposure
A study tested 47 animals at a zoo in Brazil for SARS-CoV-2. Nine animals were positive for the virus, indicating potential infection from humans. The research, led by the Universidade Federal de Minas Gerais, took samples from the animals between November 2021 and March 2023.
The study reported that 19.1% of the animals tested positive for SARS-CoV-2. The virus was found in 10.6% of rectal samples, 6.3% of oropharyngeal samples, and 5.8% of nasal samples. Two virus variants were identified: Alpha in a maned wolf and a fallow deer, and Omicron in a western lowland gorilla. Genome analysis showed close relations to human samples, suggesting the virus passed from humans to animals.
The zoo restricted visitor access from November 2021 to January 2022 due to COVID-19. During this time, three animals tested positive. After reopening to visitors in February 2022, more animals became infected, implying visitors might have increased the risk of transmission to zookeepers, who may have infected the animals.
How can zoos enhance biosecurity measures to prevent the spread of COVID-19 among their animal populations?
Interview with Dr. Maria Silva, Virologist and Lead Researcher at Universidade Federal de Minas Gerais
News Directory 3: Thank you for taking the time to speak with us, Dr. Silva. Your recent study on SARS-CoV-2 in animals at a Brazilian zoo has garnered significant attention. What motivated you and your team to undertake this research?
Dr. Maria Silva: Thank you for having me. The motivation behind our research was the rising cases of COVID-19 among animals, especially in settings where they interact with humans. Zoos are unique environments where the potential for cross-species transmission exists. We wanted to assess the infection prevalence of SARS-CoV-2 in zoo animals and understand the implications for both animal and human health.
News Directory 3: Your study found that 19.1% of the tested animals were positive for the virus, with notable findings regarding the transmission variants. Can you elaborate on these results?
Dr. Maria Silva: Certainly. We tested 47 animals and found that nine tested positive for SARS-CoV-2. The virus was detected in various sample types: rectal, oropharyngeal, and nasal. Notably, we identified two variants, Alpha and Omicron, with close genetic relationships to human samples, which suggests direct or indirect transmission from humans to these animals.
News Directory 3: The study indicated that visitor access to the zoo was restricted at certain times due to COVID-19. How did visitor interactions correlate with infection rates among the animals?
Dr. Maria Silva: The timeline is quite telling. During the restriction period from November 2021 to January 2022, only three animals tested positive. However, after the reopening to visitors in February 2022, we saw an increase in positive cases among animals. This suggests that human visitors likely heightened the risk of transmission, not just to the zookeepers but directly to the animals as well.
News Directory 3: What are the broader implications of your findings in terms of wildlife and public health?
Dr. Maria Silva: Our results highlight the importance of continuous monitoring of SARS-CoV-2 in wildlife. Ongoing viral evolution and adaptation in animals can have serious implications, potentially leading to new zoonotic outbreaks. Public health strategies must evolve to include wildlife monitoring and research, along with human disease surveillance, to effectively address and mitigate the risks posed by emerging infectious diseases.
News Directory 3: What recommendations do you have for zoos and wildlife facilities, given the risks associated with COVID-19?
Dr. Maria Silva: Zoos must implement strict biosecurity measures to protect both their animal populations and their staff. This includes limiting human-animal contact and monitoring the health of animals closely. Additionally, public education on the potential risks of zoonotic diseases should be reinforced, emphasizing the shared responsibility of keeping both humans and wildlife safe during such global health crises.
News Directory 3: Thank you for sharing your insights, Dr. Silva. We appreciate your important work in this field.
Dr. Maria Silva: Thank you for the opportunity to discuss our research. It’s crucial that we continue this dialog to protect both human and animal health.
The researchers noted that ongoing viral evolution and adaptation in animals is concerning. They emphasized the need for continuous monitoring of SARS-CoV-2 in wildlife. This monitoring helps understand transmission dynamics and prevent future zoonotic outbreaks. They called for public health strategies that include wildlife monitoring to address the risks from emerging infectious diseases.