Are cattle at risk for SARS-CoV-2 infection?

In a recent research paper published in emerging infectious diseaseresearchers evaluated antibodies targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cattle on farms in Germany.

Background

SARS-CoV-2, the causative agent of the 2019 coronavirus disease (COVID-19), has spread incredibly rapidly around the world since it was first discovered in late 2019. This massive global pandemic claimed the lives of more than 6.3 million people in a virus epidemic that lasted almost two and a half years.

Human SARS-CoV-2 infection increases the likelihood of animal infection. With a particular focus on finding vulnerable species and potential reservoir or intermediate hosts, various researchers have documented the involvement of wild and domestic species in human-animal contact surfaces since the outbreak of the COVID-19 pandemic. was evaluated.

Previous reports indicate that it is home to several animal species, including non-human primates, canines, felines, mustelidae, and white-tailed deer. crested family Rodents were susceptible to SARS-CoV-2 infection under conditions, but pigs and poultry were not. Ruminant livestock such as sheep, cattle, and goats were less susceptible after inoculation with SARS-CoV-2. Few animals can be infected without animal-to-animal transmission.

Moreover, in as little as 1-2 days, cows were tested positive for SARS-CoV-2 by reverse transcription-polymerase chain reaction (rt-PCR) after infection. Therefore, serological screening detects previously infected animals and spread infection rate in the field.

About research

In the current study, scientists serologically tested 1,000 cattle samples collected in Germany at the end of 2021 to determine the risk of COVID-19 to cattle.

In detail, the team evaluated 1,000 plasma or serum samples obtained from cattle on 83 farms in the four German federal states (Lower Saxony, Bavaria, Thuringia, and Saxony-Anhalt). As these specimens are surplus material from standard diagnostic submissions made by accountable veterinarians within the framework of health surveillance on specific cattle farms, permits are required to obtain these specimens. They pointed out that it was not necessary.

Sampling took place in fall 2021 and early winter 2021-2022. During this time, SARS-CoV-2 infections caused by the delta variant of concern (VOC) surged among humans. Researchers examined 2 to 20 randomly selected plasma or serum samples per farm. They sampled Farm 31 his twice and the animal owner was quarantined during that time.

All bovine samples were evaluated using a multiple enzyme-linked immunosorbent assay (ELISA) based on the SARS-CoV-2 receptor binding domain (RBD). The authors analyzed an additional 100 control samples of his 100 cattle randomly obtained in Germany in 2016.

result

The study results showed that among the 2021 cattle samples, 11 cattle from 9 farms were positive for the SARS-CoV-2 RBD ELISA. His one of these animals was from Farm 31 and was sampled after the owner’s quarantine. Indirect immunofluorescence using her Vero cells infected with SARS-CoV-2 2019 nCoV Muc-IMB-1 strain antigen Matrix confirmed positive ELISA results for all but one sample from Farm 8. In addition, titers varied from 1:8 to 1:512, with seropositive animals from farm 31 having the highest titers.

Evaluation of 11 RBD-ELISA positive samples utilizing surrogate virus neutralization test (sVNT) enabled identification of SARS-CoV-2 Neutralizing antibodyThis analysis was accomplished by simulating the interaction between the host cell membrane receptor protein, angiotensin-converting enzyme 2 (ACE2), and SARS-CoV-2. Additionally, four of his cows on farms 74, 47, 31, and 11 had positive sVNT results.

Conclusion

Findings show that 11 cattle samples from Germany were positive for SARS-CoV-2 antibodies, suggesting that exposure to COVID-19-infected keepers may occasionally cause cattle to become infected with the virus and seroconvert suggests that there is However, the team found no additional evidence of intraspecific viral spread in the field, consistent with previous infection assessments.

However, the authors note that another CoV (i.e., BCoV) is very common across cattle, and according to previous studies, BCoV infection did not protect against infection with SARS-CoV-2. and pointed out that future surveillance initiatives should include cattle farms. Additionally, recombination events between the two viruses could result from double infection of one animal, a process seen in other CoVs.

Due to the limited susceptibility of cattle to SARS-CoV-2, the likelihood of emergence is very low, but potential chimeras between SARS-CoV-2 and BCoV may raise further concerns. I have. The study states that outbreak studies should consider ruminants and that regular testing is necessary to prevent the spread of novel SARS-CoV-2 variants throughout the livestock population.