COVID-19 - How Long Can SARS-CoV-2 (Coronavirus) Survive on Surfaces and Air?

A novel coronavirus resulting in pneumonia-like symptoms began making the headlines in late 2019. Since it first emerged in China, this virus has spread to almost all countries in the world and has resulted in the death of thousands of humans. The virus was later named SARS-CoV-2 (severe acute respiratory syndrome coronaVirus 2), and the illness caused by the virus is called COVID-19 (coronavIrus disease - 2019).

How Does SARS-CoV-2 Spread?

SARS-CoV-2 spreads from one person to another, which is mainly through respiratory droplets produced when an infected person coughs or sneezes near you. Viruses present in these droplets can enter your nose, mouth, or eyes, and infect you.

You can also get infected if you touch your nose, mouth, or eyes when your hands are contaminated by touching a surface or object that has droplets with the virus on it. This is not considered to be the primary way this virus spreads, but there are pretty good chances that you might get infected through such indirect contact.

When an infected person sneezes or coughs into their hands and touches objects without washing their hands, the virus gets transferred to such objects. When you touch such objects and touch your face or mouth, the virus can enter the body. This is why doctors are asking us not to touch our face, nose, or mouth with unwashed hands.

Recent studies have shown that the coronavirus can survive for hours to days on various surfaces such as doorknobs, tabletops, etc. This survival rate varies depending on the material the contaminated surface is made of. These studies and researches are still at the preliminary level, but they still give a lot of useful information about the new coronavirus. They provide information on how long SARS-CoV-2 can live on the surfaces you come in contact with every day.

Does SARS-CoV-2 Stay Stable on Surfaces and Air?

According to a study from the National Institutes of Health (NIH) published in The New England Journal of Medicine (NEJM), this virus remains stable for hours to days on surfaces and in the air.

The study was conducted after depositing the virus from an infected person on surfaces that people touch commonly. SARS-CoV-2 was detectable and infectious in the air for almost 3 hours and up to two to three days on plastic and steel.

The Lancet published a second study, where a droplet containing a determined number of viruses was introduced onto a surface. The results of these studies have provided crucial information about the stability of this virus and suggested that people may get infected through the air and by touching contaminated objects.

According to the Centers for Disease Control and Prevention (CDC), the virus was found on various surfaces on the Diamond Princess cruise ship up to 17 days after the passengers disembarked. The virus was found in the cabins of both asymptomatic and symptomatic passengers infected with COVID-19.

How Long Does the New Coronavirus Survive on Different Surfaces?

SARS-CoV-2 lasts longer on smooth and shiny surfaces like metal and plastic. Surfaces that are uneven and have a lot of holes are not favorable.

The following information is based on studies conducted in controlled labs. The effects of environment and other conditions on the viability of viruses present on such surfaces are unknown.

1) Plastic:

We are literally surrounded by plastic. Almost everything we use has plastic in it. This includes our food packages, water bottles, credit cards, milk cartons, remote controls, keyboards, ATM buttons, elevator buttons, light switches, toys, etc.

The NEJM study detected the virus on plastic surfaces for up to three days, while the other study showed them to last longer (up to seven days).

2) Metal:

Metals like stainless steel and copper are used in various objects like doorknobs, refrigerators, spoons, pots, keys, jewelry, electrical wires, coins, etc.

The NEJM article found no virus on copper surfaces after 4 hours itself, and the Lancet article detected viruses on surfaces made from stainless steel for up to a week. But, the NEJM article states that no viable virus was found on stainless steel surfaces after three days (72 hours).

3) Glass:

Windows, computer screens, eyewear, mirrors, smartphones, etc., are some of the most commonly used objects made from glass.

According to the Lancet study, the virus was found on glass surfaces for up to four days.

4) Paper:

Paper is used in money, letters, magazines, newspapers, toilet papers, tissues, etc.

According to the Lancet study, no viable virus was found on tissue paper and newspaper after three hours, while the virus was detected on currency notes for almost up to four days.

5) Wood:

Most of our furniture, such as tabletop, doors, shelves, cupboards, etc., are made of wood. The Lancet study found viable viruses on wood surfaces for two days.

6) Cardboard:

Couriers, food packages, toy boxes, etc., are made from cardboard. According to the NEJM study, the virus can remain viable on cardboard for 24 hours.

7) Clothes and Shoes:

The study published in the Lancet article states that the virus is viable for 48 hours (2 days) on clothes. And the majority of samples collected from the shoes of hospital staff caring for COVID-19 patients showed the virus to be present on them.

8) Food and Water:

SARS-CoV-2 is not known to spread from food and water. All the species of coronaviruses do not do well in food. But, the packages in which the food comes in might still be contaminated.

These numbers will be affected by factors like temperature and humidity. In higher temperatures and humidity levels, the virus survived for a shorter time (CDC).

How to Clean Such Contaminated Surfaces?

Make sure you clean and disinfect all high-touch surfaces. These include doorknobs, all handles, switches, taps and faucets, toilets, staircase railings, keyboards, and phones. Clean these surfaces while wearing a disposable mask and gloves. In case you are not using gloves, wash your hands immediately after you clean these surfaces.

Floors and Other Surfaces:

CDC recommends using EPA-registered disinfectants or household bleach solutions. To make a bleach solution:

• Mix five tablespoons of bleach in a gallon of room temperature water.

• Mix four tablespoons of bleach in four cups of room temperature water.

Smartphones:

For cleaning electronics and smartphones, alcohol-based wipes or alcohol sprays (70 % Ethanol) can be used.

Clothes:

Wash your clothes with regular detergent in the warmest washing machine setting. If you are washing them with your hands, wear a mask and gloves. Let the clothes dry properly under the sun or in the dryer.

Conclusion:

The data presented in this article are based on studies there were conducted in a lab. In the real world, even if any surface has SARS-CoV-19 on them, it does not mean that you will definitely get infected. As this virus is extremely sensitive to environmental conditions like heat and humidity, the virus can lose its stability fast. So the number of viruses present on the surface will keep reducing with time.

You are more likely to get infected directly from an infected person than such contaminated objects. There is a lot to learn about this virus, so wash your hands, keep distance, and stay healthy!