As the Medical Director of the Kansas Business Group on Health I’m sometimes asked to weigh in on hot topics that might affect employers or employees. This is a reprint of a blog post from KBGH:

Let’s get the semantics out of the way. “Viruses” are little more than small packaged strands of genetic material—DNA or RNA—that invade cells and trick those cells into reproducing the virus. The duplicates of the virus take up too much space inside an infected cell, and the cell ruptures like a balloon. This is how tissue damage occurs, like the sore throat you get with many respiratory viruses. Most viruses infect other organisms, ranging from bacteria to mammals and birds, and are harmless to humans. You can find hundreds of harmless viruses in a few ounces of seawater, for example.

But sometimes viruses cross over from other hosts to infect humans. We call such infections “zoonotic.” Coronaviruses are a family of RNA viruses similar in many ways to influenza. They are called “corona” viruses because of their “crown” of spiky proteins. Four common coronaviruses—229E, NL63, OC43, and HKU1—have long been known to infect humans. They cause colds. We’ve seen outbreaks of two other coronaviruses in the last couple decades. Severe Acute Respiratory Syndrome (SARS) was transmitted to humans from civet cats. Middle East Respiratory Syndrome (MERS) came from camels. The novel coronavirus discovered in 2019 in Wuhan, China, the seventh known coronavirus to infect humans, is likely either from bats or pangolins, those scaly mammals that look like a cross between a raccoon and a lizard.

The newly discovered virus is now officially known as “SARS-CoV-2,” short for “severe acute respiratory syndrome coronavirus 2.” The disease that SARS-CoV-2 causes is officially known as “COVID-19,” short for “coronavirus disease 2019.” But for the sake of conversation, let’s use “COVID-19” for the next 800 words.

By contrast, COVID-19 seems only slightly more contagious than a generic influenza strain, with an r0 so far between two and three. It is also a fairly middling organism, mortality-wise: it has a current observed mortality rate of two percent, a number which will probably decrease over time.

The identification and naming of the virus and the work already done toward producing a vaccine is a testament to the advancement of science. We have accomplished all this in the time it took to even identify H5N1 23 years ago. But in spite of this, we are unlikely to be able to contain the virus. Since the original index case of presumed bat-to-human or pangolin-to-human transmission, COVID-19 has proven able to be transmitted directly from human to human. We measure the human-to-human contagiousness of a virus by a statistic called r0 (pronounced “R naught”). The r0 is complex to calculate, but it ultimately reflects the number of other people a person with an infection can be expected to, in turn, infect. Some viruses have an astonishingly high r0. A person with measles, for example, can be expected to infect between twelve and eighteen others. HIV’s r0 is 4.3.

By contrast, COVID-19 seems only slightly more contagious than a generic influenza strain, with an r0 so far between two and three. It is also a fairly middling organism, mortality-wise: it has a current observed mortality rate of two percent, a number which will probably decrease over time. A particularly bad influenza virus has a mortality rate of 20 percent (as in the 1918 Spanish flu, which may have in fact originated in Kansas) or even 60 percent, as observed in Asian Avian Influenza A (H5N1). But the fact that COVID-19 kills few of its victims has the paradoxical effect of increasing its transmission. Those H5N1 patients either died quickly or got so ill so quickly that they could be isolated right away, so only a few hundred people eventually died. As Dr. James Hamblin writes in the Atlantic this week, “…much ‘milder’ flu viruses, by contrast, kill fewer than 0.1 percent of people they infect, on average, but are responsible for hundreds of thousands of deaths every year.”

So even with the quarantine of hundreds of millions of people in China and elsewhere, COVID-19 cases are now in dozens of countries, including the United States. We’ve now seen the first case of likely “community-acquired” COVID-19 in the U.S. Epidemiologist Dr. Mark Lipsitch told James Hamblin that, eventually, 40 to 70 percent of the world’s population will become infected, likely resulting in flu and cold seasons being slightly worse in intensity and slightly more diverse, virus-wise.

What do we tell our employees, then? The news is fast-moving, and I’ve already revised this blog post twice in two days before posting, so nothing mentioned here should be considered irrefutable. But the fundamentals of disease containment are well-established, they’re not sexy, and they don’t differ for COVID-19 at this point compared to other infections. If you get sick, CDC recommends that you:

1. Stay home except to get medical care.

2. Separate yourself within the home from others, including pets.

3. Wear a facemask if you’re forced to be around others, including pets.

4. Cover your coughs and sneezes.

5. Don’t touch your eyes or nose.

6. Wash your hands for at least 20 seconds with soap and water. If you can’t get to soap and water, use a hand sanitizer with at least 60% alcohol. THIS IS LIKELY THE BEST PIECE OF ADVICE WE HAVE.

7. Don’t share household items.

8. Clean all your “high-touch” surfaces, like counters and doorknobs, daily.

9. Once you are free from fever without using medications, free from symptoms including cough, and have had two negative sputum tests, CDC says you can be released from isolation.

If you’re around someone who is sick, CDC’s advice is the same: help the patient with basic needs to allow him or her to stay home, like groceries; monitor his symptoms, and if he’s getting sicker call his doctor; and wear a facemask and gloves when you interact or do laundry.

For businesses, CDC has similar interim guidance:

1. Encourage sick employees to stay home.

2. Separate and send home sick or coughing employees right away.

3. Encourage good hand hygiene and cough/sneeze etiquette.

4. Clean surfaces often.

5. Check CDC Traveler’s Health Notices before traveling.

And for heaven’s sake, if you haven’t already had a vaccination against influenza, get one now. It is not too late. You are still far, far more likely to get sick or die from influenza than from COVID-19; influenza causes between 12,000 and 61,000 deaths per year in the United States, yet we can’t get much more than about 50% of people to get immunized in any given year.