A news story has been making the rounds on social media inaccurately saying that the CDC found coronavirus on the Diamond Princess cruise ship 17 days after people left the ship. The coronavirus is made of genetic material (RNA) wrapped by lipids and proteins. You need all of that to infect people. The cited CDC study just looked at whether viral RNA was present, not whether there was still infectious virus. There have been some studies looking at how long intact virus can survive on surfaces, and it does look like the virus can survive on some surfaces up to 3 days. However, the number of surviving virus on the surface drops rapidly. Additionally, you can’t get infected just by touching a surface–you have to get that virus into your respiratory system, for instance by touching your face, especially your eyes or nose. Similarly, coronavirus can’t infect you by coming through a cut or if you eat it. So, bringing in packages, takeout, and groceries is totally fine as long as you wash your hands before touching your face. I’ve answered some common questions about coronavirus transmission below.
How Is Coronavirus Transmitted?
To get infected, the coronavirus must get into your respiratory system. The major route of transmission is from being in close contact (less than 6 ft away) with an infected person. Respiratory droplets formed when the person coughs or sneezes then can enter your mouth or nose. It is possible that touching a contaminated surface and then touching your face can cause infection, but this is not thought to be the main way that the virus is spread.
Can You Get Coronavirus Just From Breathing the Air in a Room an Infected Person Just Left?
This is very unlikely, except potentially in medical settings. Coronavirus isn’t ‘airborne’ as an aerosol under normal conditions. When people sneeze or cough, larger respiratory droplets stay in the air for about 3 seconds before dropping. Some medical procedures can produce an aerosol, which is like fog–much smaller particles that can remain in the air for a longer time. This is why it is so important for medical professionals to have access to N95 masks and other personal protective equipment (PPE). For the rest of us, as long as we stay 6 feet away from an infected person we shouldn’t be worried about getting infected by breathing the same air as them.
Do I Need to Leave My Groceries Out in the Garage for 3 Days?
Contrary to what a widely circulating video suggests, you really don’t need to leave groceries outside for 3 days or to sterilize every item you bring in. While you are unpacking and handling the groceries or packages, make sure you don’t touch your face. Wash your hands afterwards and wipe down the counters and you should be fine. While it is theoretically possible to get infected by touching a surface, this does not seem to be a major route of disease transmission.
Can I Get COVID-19 From Eating Food Prepared By An Infected Person?
There is no evidence for transmission of coronavirus via food. Again, the virus needs to get into your respiratory system. If the coronavirus managed to survive the heat during cooking, it would be destroyed by the acid in your stomach. Of course, it is still important to wash your hands before eating.
The Bottom Line: To reduce your chances of getting COVID-19, wash your hands with soap and water often, clean often used surfaces in your home, and practice social distancing by staying at least 6 ft away from everyone not in your household.