Researchers at the University of North Carolina recently discovered a highly pathogenic virus, Swine Acute Diarrhea Syndrome Coronavirus (SADS-CoV), with the potential to infect humans.
Earlier this year, scientists in China discovered a new strain of swine flu circulating among the swine population. The virus, called G4 H1N1, was a descendant of the strain that caused the swine flu pandemic of 2009. Their results showed the swine virus replicated in human cells thus, making it capable of causing a future pandemic.
It seems another potential zoonotic virus has emerged in the swine population as reported in the journal Proceedings of the National Academy of Sciences (PNAS). Researchers believe the virus first emerged from bats.
SADS-CoV is an alphacoronavirus that causes vomiting and acute diarrhea in pigs. Since its discovery in 2016, the virus has infected swine herds across China. Furthermore, it is associated with a 90% mortality rate in piglets.
While many investigators focus on the emergent potential of the betacoronaviruses like SARS and MERS, actually the alphacoronaviruses may prove equally prominent — if not greater — concerns to human health, given their potential to rapidly jump between species.
Ralph Baric, professor of epidemiology at UNC-Chapel Hill
Can the Swine Coronavirus Jump to Humans?
Scientists at the University of North Carolina designed a synthetic version of the virus and injected it into different human cell types in the lab. They aimed to evaluate the virus’s ability to replicate and the risk of cross-species contamination.
The virus was seen to infect a wide range of mammalian cells including human lung and intestinal cells. A higher growth rate was seen in human intestinal cells. Thus, concluding that human cells are susceptible to infection. However, the virus has not infected humans out of a lab setting as yet.
It is impossible to predict if this virus, or a closely related HKU2 bat strain, could emerge and infect human populations. However, the broad host range of SADS-CoV, coupled with an ability to replicate in primary human lung and enteric cells, demonstrates potential risk for future emergence events in human and animal populations.
Caitlin Edwards, a research specialist and Master of Public Health Student at UNC-Chapel Hill
A Potential Treatment for a Potential Virus
The team of researchers also tested Remdesivir, a broad-spectrum antiviral, as a potential treatment for the infection. It was found to effectively block viral replication. Therefore, providing researchers with a treatment option in case of a ‘human spillover event.’
In conclusion, the authors of the study suggest continuous monitoring of both swine workers and the swine population for any signs of SADS-CoV infection.
References:
Sun H., et al. Prevalent Eurasian avian-like H1N1 swine influenza virus with 2009 pandemic viral genes facilitating human infection. Proceedings of the National Academy of Sciences. Jul 2020, 117 (29) 17204-17210; DOI:10.1073/pnas.1921186117
Caitlin E. Edwards, Boyd L. Yount, Rachel L. Graham, Sarah R. Leist, Yixuan J. Hou, Kenneth H. Dinnon, Amy C. Sims, Jesica Swanstrom, Kendra Gully, Trevor D. Scobey, Michelle R. Cooley, Caroline G. Currie, Scott H. Randell, Ralph S. Baric. Swine acute diarrhea syndrome coronavirus replication in primary human cells reveals potential susceptibility to infection. Proceedings of the National Academy of Sciences, 2020; 202001046 DOI: 10.1073/pnas.2001046117
