Is anyone untouched by the Covid19 pandemic? Some of our critical research projects are on hold, mostly due to no PPE for personnel to handle study lab animals and also travel restrictions. We are fully functional at our lab. We are using any extra time to evaluate data and share our findings with veterinarians and horse owners through Zoom meetings. Check out the Facebook meeting posts to find the links and join us in our Zoom room. Until then, here are some facts that help us focus on what is important. The information is up to date as of mid-April.
The SARS-CoV-2 strain of a novel Coronavirus appeared in Asia in 2019 and is known as Covid2019…Covid19 for short. SARS is an acronym for severe acute respiratory syndrome caused by a betacoronavirus that is transmitted by contact with fomites. Fomites are infectious materials transmitted by contact with respiratory droplets or body fluids. Unfortunately for us this virus is transmitted by airborne particles. Symptoms include fever, headache, body aches, dry cough, hypoxia (lack of oxygen), and usually pneumonia. For you molecular biologists, SARS-CoV are enveloped, positive-sense, single-stranded RNA virus that infect the epithelial cells within the lungs. SARS-CoV-1 binds the ACE2 (angiotensin-converting enzyme 2) receptor and infects humans, bats, and palm civets. We learned about SARS-CoV-1 in 2003. There are seven coronaviruses that infect humans. In the 2003 SARS outbreak 9% of patients with confirmed cases died, the hardest hit population was over 60 and over 50% of these people died.
The evolution of SARS-CoV is interesting. There were two different strains of SARS-CoV isolated in China in 2003, indicating there were separate species crossing events. The virus came from wild animals sold as food in a market in Guangdong, China and it was isolated from asymptomatic masked palm civets. This virus was able to infect humans, raccoon dogs, ferret badgers, and domestic cats. The virus could not be maintained in tissue culture and it did not infect bats until the virus was altered in 2008 in a laboratory to contain a human receptor binding domain. That indicated to researchers that bats could be asymptomatic and serve as a natural reservoir for the virus. And a note for Julie, the raccoon dog, also known as the mangut, tanuki or neoguri, is a canid indigenous to East Asia. It is the only canid species that can climb trees.
The recent ancestor for all coronavirus existed in 8000 BCE. Some say the virus existed 55 million years ago. They coevolved with birds and bats. Bats are the reservoir for alpha and betacoronavirus while birds serve the same role for the gamma and deltacoronavirus. The global range allowed evolution and dissemination of this virus family.
The path to human infection is from leaf-nose bats to horseshoe bats, civets, and finally to humans. Bovine coronavirus evolved from rodents and crossed species to equids. It was in the 1890’s when bovine coronavirus jumped to people, and the likely cause of the “flu” pandemic that same year.
Of interest to us is that human corona virus (OC43) causes respiratory infections and is suspected of playing a role in neurological diseases. Mouse hepatitis virus (MHV) is a coronavirus that causes epidemic murine illness that has a high mortality. Prior to the discovery of SARS-CoV, MHV had been the best-studied coronavirus both in vivo (in the animal) and in vitro (in tissue culture) as well as at the molecular level. Some strains of MHV cause a progressive demyelinating encephalitis in mice which has been used as a murine model for multiple sclerosis.
Human coronaviruses vary in risk factors and disease severity. Some (MERS-CoV) are deadly to more than 30% of those infected and others just cause an irritating, common cold.The human coronavirus discovered in 2003, SARS-CoV-1 has a unique pathogenesis because it causes both upper and lower respiratory track infections.
Six species of human coronaviruses are known. One species is subdivided into two different strains, making seven strains of human coronaviruses altogether. Four of these strains continually circulate in the human population and produce the generally mild symptoms of the common cold: OC43, HKU1, HCoV-229E, NL63. These viruses cause about 15% of commons colds (the majority of colds are infections caused by rhinoviruses).
Four coronavirus strains have a seasonal incidence occurring in the winter in temperate climates. There is no preference towards a particular season in the tropics. Three strains (two species) produce symptoms that are potentially severe; all three of these are β-CoV strains: MERS-CoV, SARS-CoV-1, SARS-CoV-2. The two SARS-CoV strains have occurred in the last 17 years, both from Chinese wet markets.
How does all this affect us? The Center for Disease Control has updated its guidelines for essential workers that have been exposed to people infected with SARS-CoV-2. Workers that do not feel sick are able to return to work so long as they take their temperature before leaving the workplace, wear a face mask at all times, and practice social distancing.
The department of Homeland Security and Health and Human Services outlines how removing shelter-in-place type restrictions after 30 days would lead to a second, very high peak in the number of cases and deaths. The number of expected deaths is 300,000. The spike in deaths was projected to occur abut 150 days after lifting the stay-at-home restrictions. We are staying put so you can expect more Zoom meetings.
Its concerning that United States hospitals are seeing a shortage of antibiotics, antivirals, and sedatives required by patients on ventilators. Increased demand and effects of the pandemic has halted production of some drugs. The University of Minnesota has analyzed the supply chain and identified 156 drugs that could go into shortage in the next 90 days, but they have not released the list.
The numerous studies and information on chloroquine on the outcome of COVID-19 patients are so far inconclusive or halted due to a high number of complications. A vaccine trial, called the Solidarity Vaccine Trial will evaluate multiple candidate vaccines at the same time, against a placebo. The expectation is the researchers will have results in 3-6 months due to high enrollment and an adaptive design. We will be in line for that vaccine when it is ready.
Pathogenes laboratory wishes you and your families well. We will continue to be here to help you with your horses by testing sera, developing new avenues of research and answering your questions about neurodegenerative diseases. Give us a call or join us through Zoom meetings.