Would it surprise you to know that many of us have had a coronavirus infection at some point in our lives?
Along with rhinovirus, adenovirus, influenza A&B, parainfluenza virus 1-4, and respiratory syncytial virus, human coronaviruses are associated with upper and lower respiratory tract infection. They include the common cold, bronchitis, and pneumonia.
However, COVID-19, SARS-CoV, and MERS-CoV are coronaviruses that have crossed to humans from other species (bats, camels). It probably took a few mutations and many years to accomplish this trick but it means folks like us have no historical immunity.
COVID-19, so prominent in the news today, causes a range of conditions from asymptomatic infection to mild upper respiratory disease or pneumonia with or without fever. Fortunately, the majority of cases appear to be mild, but because of that we really don’t know what the true mortality rate is because the denominator could be much larger than we think.
COVID-19 is what’s known as an enveloped RNA virus. This means its genome is RNA rather than DNA and is coated by a lipid and protein membrane. Infection in humans starts when the virus docks to a susceptible cell in the respiratory tract using one of its spikes (the spikes give the virus a crown appearance, hence the name).
The virus is then taken into the cell where it uncoats and releases its RNA genome into the cell. The RNA serves as a template and converts the cell into a virus factory. New viruses leave the infected cell when it bursts open. Fun fact 1: Enveloped viruses are less viable over time on inert surfaces and susceptible to drying and an acidic pH.
Like other respiratory viruses, COVID-19 is passed from person to person by contact with respiratory secretions and droplets produced while coughing or sneezing. Unlike other common respiratory viruses though, it appears that COVID-19 might be spread by the airborne route (like measles).
In addition, the virus can be found in stool, which suggests that it can be transmitted by the fecal-oral route, so wash your hands after going to the loo. An infected patient’s dog tested positive for the virus but no one knows if it was infected or contaminated.
Here are some commonly asked questions and answers:
Q: Can COVID-19 be treated with antibiotics?
A: Nope and you don’t want to be altering your normal, protective microbiome, so don’t go there.
Q: Are there any effective antiviral medications?
A: Not with established clinical trials but a variety of old and new compounds are being evaluated as we speak. Fun fact 2: one of the drugs developed to treat Ebola seems to work with COVID-19 in the lab.
Q: What about a vaccine?
A: Moderna therapeutics has developed a vaccine and submitted it to the government for evaluation. Likewise, other companies are working overtime to generate a vaccine but by the time these are tested for human safety and efficacy it might be a year or so down the road before one is approved for use. Look how long it took to get an Ebola vaccine. Fun fact 3: Vaccines have been mass produced using genetically modified tobacco plants in the past so maybe our (in)famous crop will do some good?
Q: What can I do to protect myself and my family?
A: There are three answers and they all are “wash your hands frequently” — soap, hot water, and vigorous rubbing or an alcohol-based hand antiseptic (not Jack Daniels). If you want to disinfect surfaces at home you can generally use a 1:10 diluted bleach solution for countertops and other durable surfaces (not metal) or Lysol. This does not include body parts or as a mouthwash.
Q: Should I wear a mask?
A: Only after you have become infected. Masks are no fun to wear and they won’t stop infection. In fact, they could increase the likelihood of infection if you are constantly touching your mask around your mouth.
Q: Can my doctor test me for COVID-19?
A: At the moment, only public health labs are providing testing using a CDC-developed assay so routine testing will likely be limited. But companies who currently provide rapid respiratory tract infection tests are probably working diligently to add COVID-19 to their panels.
Bottom line? Use good hand hygiene, avoid putting fingers into your mouth, eyes, or nose (eww), practice good surface disinfection, stay at home when you are sick, stop smoking/vaping if you do, and carry around a $2 bill in your wallet for luck. That last one doesn’t work but it can’t hurt.
One last bit of advice: Only one case of COVID-19 has been identified in North Carolina (Wake County) as of this writing, so if you start getting symptoms of the common cold, it’s probably the common cold. But do your personal physician a favor and call first if you are experiencing symptoms rather than dropping into the office unannounced to avoid spreading illness to staff and other patients.
PS: there is no association between COVID-19 and Corona beer (16 percent of Americans think there is, argh).
Dr. Michael Dunne lives in Whispering PInes and is a board-certified medical and public health microbiologist and a fellow of the Infectious Diseases Society of America and the Pediatric Infectious Diseases Society.