New Animal Coronaviruses are Infecting Humans More Often than We Realize

Dr. Anastasia N. Vlasova, PhD, DVM (Source: UTMB One Health Collaborators. https://www.utmb.edu/one-health/partners/collaborators

By: Anthony D’Angelo

The COVID-19 pandemic has shown that coronaviruses can be both highly infectious and pathogenic. Before SARS-CoV-2 spread across the world, other human coronaviruses, such as SARS-CoV-1 and MERS, were found to be contagious and deadly in humans. However, coronaviruses are also very common in other animals as well, and some of these strains have been shown to be able to infect humans and cause acute respiratory illness. 

Recent research published in the journal Emerging Microbes and Infections by Dr. Anastasia Vlasova, DVM, PhD  and her coauthors identified several cases of canine, feline and porcine like (CFPL) alphacoronaviruses associated with acute respiratory disease in humans. The first evidence that CFPL-associated coronaviruses are associated with disease in humans was initially discovered in 2018, when Dr. Gregory Gray, MD, MPH and his team were working with collaborators in Sarawak, Malaysia. Upon isolation and characterization by Dr. Vlasova and her colleagues, the virus was found to be a new coronavirus that had 99% similarity to previously discovered canine coronaviruses (1). Subsequently, in the current study, a critical review of the literature found acute respiratory illness outbreaks associated with CFPL-associated coronaviruses in patients in three countries (2). Using BLAST, Dr. Vlasova compared coronavirus genomes isolated from outbreaks in Thailand in 2002, the United States in 2014, Haiti in 2017, and the most recent CFPL-alphacoronavirus outbreak detected in Malaysia in 2018. The results from this analysis showed that these novel strains of CFPL-alphacoronaviruses were highly similar to each other, as well as previously discovered animal coronaviruses. Interestingly, these new strains were also quite different from human coronavirus 229E (HCoV 229E), which can cause the common cold.  

 


Immune transmission electron microscope image of canine coronavirus (CCoV)–human pneumonia (HuPn)–2018 isolated from Sarawak, Malaysia. (Image source: Vlasova, A. N., Diaz, A., Damtie, D., Xiu, L., Toh, T. H., Lee, J. S., Saif, L. J., & Gray, G. C. (2022). Novel Canine Coronavirus Isolated from a Hospitalized Patient With Pneumonia in East Malaysia. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 74(3), 446–454. https://doi.org/10.1093/cid/ciab456)

How does all of this relate to One Health? As Dr. Vlasova states, “the big problem that the whole world has witnessed was COVID-19. There was simply not enough information…on the fact that coronaviruses were already present in some bat species and that they were potentially infectious to humans”. As most recent evidence shows, COVID-19 is believed to have come from an animal source before adapting to become more effective in spreading among humans. Despite this, Dr. Vlasova says “it is impossible to get funding from NIH [National Institutes of Health] to study animal coronaviruses…we simply do not know the whole diversity and pathogenic potential of all coronaviruses circulating in animals. The attention only goes to those coronaviruses that cause trouble in humans, and that needs to be shifted”.  

As Dr. Vlasova’s research has shown, animal coronaviruses can cause clinical disease in humans. Key questions remain. Were the canine coronaviruses studied by Dr. Vlasova transmissible between humans? What can cause an animal coronavirus to become transmissible to humans? Why do some animal crossover events cause only mild disease, while others cause severe respiratory symptoms, such as that seen with SARS-CoV-1, MERS-CoV, and COVID-19? A One Health approach, emphasizing cooperation between the various disciplines, can better progress research into these questions and potentially avert a future pandemic.


The full article can be reviewed here

References:

  1. Vlasova, A. N., Diaz, A., Damtie, D., Xiu, L., Toh, T. H., Lee, J. S., Saif, L. J., & Gray, G. C. (2022). Novel Canine Coronavirus Isolated from a Hospitalized Patient With Pneumonia in East Malaysia. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 74(3), 446–454. https://doi.org/10.1093/cid/ciab456
  2. Vlasova, A. N., Toh, T. H., Lee, J. S., Poovorawan, Y., Davis, P., Azevedo, M., Lednicky, J. A., Saif, L. J., & Gray, G. C. (2022). Animal alphacoronaviruses found in human patients with acute respiratory illness in different countries. Emerging microbes & infections, 11(1), 699–702. https://doi.org/10.1080/22221751.2022.2040341

Subscribe to the UTMB One Health Newsletter

* indicates required