On January 19, 2020, a 35-year-old man presented to an urgent care clinic in Snohomish County, Washington, with a four-day history of cough and fever. He was given a mask to wear while in the waiting room. After a 20-minute wait, he was examined, at which time he disclosed that he had returned to Washington State on January 15th after traveling to visit family in Wuhan, China. He had read the health alert from the Centers for Disease Control and Prevention (CDC) and decided to see a health provider.
On January 20, 2020, the CDC confirmed that COVID-19 was indeed in the United States.
As of this publishing, we are still learning how COVID-19 spreads, the severity of illness it causes, and to what extent it will spread in the United States.
COVID-19 Transmission: What the Evidence Shows (So Far)
If you have been following this crisis as it unfolds on a daily basis, as so many of us are, the number of cases related to close contact with an infected individual is striking. COVID-19 has long since ceased to be an illness only seen in those who travel.
Per the CDC, the virus is spread person to person mainly via respiratory droplets. This transmission occurs between people who are in close contact (about six feet) with someone who is infected via respiratory droplets from coughs or sneezes, which may then land in the mouth or nose of anyone nearby or be inhaled into the lungs.
People are thought to be the most contagious when they are most symptomatic. There’s evidence as well for asymptomatic or presymptomatic spread, although it’s still unclear just how much this is occurring. COVID-19 may also be transmitted by touching a surface or object with the virus on it and then touching one’s own mouth, nose, or possibly eyes. But again, it’s unclear just how much this type of transmission is occurring.
Research published in the New England Journal of Medicine suggests that the virus can live in the air and on surfaces from several hours up to several days. The study found that the virus is viable for up to 72 hours on plastics, 48 hours on stainless steel, 24 hours on cardboard, and 4 hours on copper. It is also detectable in the air for three hours. These are frightening numbers—but, according to Carolyn Machamer, professor of cell biology from the Johns Hopkins School of Medicine— also a bit misleading.
Per Dr. Machamer, less than 0.1 percent of the starting virus material remains on plastic at the 72-hour mark, making infection theoretically possible but unlikely at these levels. The same is true for the amount of virus material detected in the air after three hours. The experimental aerosols used in labs are smaller and remain in the air at face level longer. Respiratory droplets from coughs and sneezes sink to the ground much faster. According to Dr. Machamer, you are more likely to get the virus from being next to someone who is sick with COVID-19 than you are from any surface item.
This research, though inconclusive, is still important. But the fact remains that we will probably not have many of the answers we need until this crisis has passed. Time must be spent aiding patients and healthcare workers through these very challenging days. Research done following the crisis will be crucial in truly understanding how the virus is transmitted and what will most effectively keep it at bay.
Protecting Ourselves and Others from COVID-19
So what can be done to protect ourselves as the number of the infected continues to rise? The CDC’s recommendations are still our best defense:
- Wash your hands often with soap and water for at least 20 seconds, especially after you have been in a public place, or after blowing your nose, coughing, or sneezing.
- Follow social distancing guidelines.
- Avoid touching your eyes, nose, and mouth with unwashed hands.
- Avoid close contact with people who are sick.
- Stay home if you are sick.
- Cover your coughs and sneezes.
Protecting Your Living Space
Home is not only where our heart is—it is the one place we should all feel safe and protected. To protect your home, the CDC recommends:
- Always wear disposable gloves to clean and disinfect.
- Clean surfaces with soap and water to remove some of the germs.
- Practice routine cleaning of frequently touched surfaces, including tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, sinks, and remotes.
- Follow the cleaning with a household disinfectant.
- Always follow the directions on the product label to ensure safe and effective use. Some products recommend keeping the surface wet for a period of time or wearing gloves and ensuring that you have good ventilation while you are using it.
- Diluted bleach solutions may be used if appropriate for the surface, but be sure to check the product’s expiration date. Unexpired household bleach will be effective against coronavirus when it’s properly diluted. Follow the manufacturer’s instructions for application and proper ventilation. Never mix household bleach with ammonia or any other cleanser.
The CDC also provides guidelines for cleaning specific surfaces, such as:
- Soft surfaces such as carpeted floors, rugs, and drapes
- Clean using soap and water or with cleaners appropriate for use on these surfaces.
- Launder these items if possible, using the warmest appropriate water setting and drying items completely.
- Consider putting a wipeable cover on electronics.
- Follow the manufacturer’s instructions for cleaning and disinfecting.
- Wear disposable gloves if you are handling dirty laundry from someone who is sick. Wash your hands with soap and water after removing the gloves.
- Do not shake dirty laundry.
- Launder items using the warmest appropriate water setting and dry items completely.
- Dirty laundry from an ill person CAN be washed with other people’s items.
- Clean and disinfect clothes hampers according to guidance for surfaces.
Many questions are still unanswered at this time, there is no doubt about that. Whether the virus is hiding on surfaces or in plain sight as an infected person, we do have concrete recommendations on how to stay well. We know that social distancing and the hygiene practices noted above have an impact.
While this situation is certainly something most of us felt we would never see in our lifetime, we will get through this. Stay educated, stay home if you are able, and stay well.
- CDC. (2020). Coronavirus Disease 2019 (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html
- CDC. (2020). How to Protect Yourself. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html
- CDC. (2020). Cleaning and Disinfecting Your Home. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/disinfecting-your-home.html
- Holshue, M., Debolt C., et al. (2020). First Case of 2019 Novel Coronavirus in the United States. New England Journal of Medicine. 382(10), doi: 10.1056/NEJMoa2001191.
- John Hopkins University. (2020). How long can the virus that causes COVID-19 live on surfaces? Hub. https://hub.jhu.edu/2020/03/20/sars-cov-2-survive-on-surfaces/