The virus that causes COVID-19 can survive on solid surfaces for days, but infection risk from contaminated objects is unknown

In response to the spread of the novel coronavirus, SARS-CoV-2, many social media posts bear warnings about the virus from unnamed friends and family members working in health fields. One such claim on Facebook, shared more than 16 million times since it was first posted 16 March 2020, states that SARS-CoV-2, the virus that causes COVID-19, “is spreading quickly from gas pumps [and] shopping carts as well.” The claim is partially correct, in that early studies show that SARS-CoV-2 could potentially be spread through contact with contaminated objects^[1]. However, there is not yet any direct evidence that this has occurred and the number of people who might contract the virus this way is unknown.

According to the Centers for Disease Control and Prevention (CDC), SARS-CoV-2 spreads primarily through person-to-person contact. When an infected person coughs or sneezes, the individual releases tiny virus-laden droplets that can land on a person nearby or be inhaled into the lungs. Based on data available at this point, which are limited, the CDC website states, “It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.”

A recent study found that SARS-CoV-2 remains infectious for up to three days on stainless steel and plastic (see figure)^[2] and previous studies of other coronaviruses, such as those that caused the SARS and MERS outbreaks, have shown that those viruses can live for up to nine days on smooth surfaces, such as glass, metal, and plastic^[3].

 

Figure—The length of time SARS-CoV-2 persists on different materials. (Source^[2])

 

The virus likely also survives on porous surfaces such as paper and fabric, which contain tiny holes, though possibly for shorter amounts of time than on smooth surfaces. SARS-CoV-2 survives for about 24 hours on cardboard^[2]. James Lloyd-Smith, an infectious disease researcher at the University of California, Los Angeles, speculated to the BBC that the holes in porous materials draw away fluids, causing the viral particle to dehydrate. A study by researchers at the University of Hong Kong, which has not yet been peer-reviewed by other scientists, reports that SARS-CoV-2 can be detected on fabric after one day and on the outer surface of surgical masks for up to seven days^[4].

“This virus is quite transmissible through relatively casual contact, making this pathogen very hard to contain,” said Lloyd-Smith. “If you’re touching items that someone else has recently handled, be aware they could be contaminated and wash your hands.”

A new report from the CDC states that scientists detected genetic material from SARS-CoV-2 inside of cabins on the Diamond Princess cruise ship 17 days after the boat was evacuated^[5]. The report’s authors point out that the data cannot say whether the virus was still viable, or what role contaminated objects, called fomites, played in spreading the virus aboard the ship.

Environmental factors, like temperature and humidity, can impact how long a virus remains viable on a surface. For example, SARS-CoV-2 appears to break down faster at warmer temperatures compared to room temperature^[4].

“UV light is a powerful inactivator of SARS-CoV^[6] [the virus that caused the SARS outbreak] and is likely to also inactivate SARS CoV-2,” said Ivo Foppa, a senior research scientist at Batelle Memorial Institute in Atlanta. “As gas pumps are usually outside, I would be more suspicious of grocery carts than of gas pumps.”  

While the exact risk of contracting SARS-CoV-2 from contaminated surfaces is unknown, the CDC says that people can reduce that risk by cleaning their hands frequently with soap and water or hand sanitizer and not touching their nose, mouth, and eyes while in public. Also, contaminated surfaces can be disinfected using diluted household bleach, solutions containing at least 70% alcohol, or one of the commercially available disinfectants recommended by the U.S. Environmental Protection Agency.

In summary, while it is possible that a person can contract SARS-CoV-2 from gas pumps and shopping cart handles, it is unknown whether these are a major source of new infections. People can protect themselves from contracting the virus from surfaces through proper handwashing, using hand sanitizer, and by cleaning surfaces with approved disinfectants.

The claim that SARS CoV-2 “is spreading quickly from gas pumps [and] shopping carts as well” is of “Neutral” credibility. One of the characteristics that makes SARS CoV-2, the virus causing COVID-19, so problematic is its environmental stability, especially on stainless steel and plastics^[4]. That means that the virus can potentially be transmitted between people by means of contaminated objects (fomites). The more people touch a particular object the higher the chance that one of those people carried viable SARS CoV-2 on their hands, thus creating a fomite. Clearly, both gas pump handles and grocery carts are frequently touched by many different people, making both suitable fomites that could aid the spread of COVID-19. The following things need to be considered, though:

1.     It is unclear how likely it is that a SARS CoV-2 infected person would carry an amount of virus on their hands such that an infectious dose might be transferred to a person from that fomite.
2.     COVID-19 is not transmitted to somebody who touches something with their hands that contains SARS CoV-2; in order for the virus to be transmitted, that person has to touch their eyes, nose, or mouth with their contaminated hands. Therefore, hand hygiene is extremely important. Furthermore, and I have not found literature on that, but what I think is of greater concern are virus particles aerosolized, e.g., by a COVID-19 infected [individual] coughing, etc. 

UV light is a powerful inactivator of SARS-CoV^[6] and is likely to also inactivate SARS-CoV-2; as gas pumps are usually outside, I would be more suspicious of grocery carts than of gas pumps.

The importance of indirect contact transmission for COVID-19 is not defined yet, but it is common for respiratory diseases. There is a report suggesting that indirect contact transmission of COVID-19 might occur^[1]. Our recent work on SARS-CoV-2 stability on different surfaces indicates that this virus can still be infectious for days in some surfaces (e.g., four days on a stainless steel surface)^[4].

With this evidence, I would say there might be a risk, but there is insufficient data for us to measure this risk. Thus, it is important to maintain good hand hygiene.

SARS-CoV-2 can be spread by surfaces contaminated with respiratory secretions from infected individuals. This would apply to any surface that people come in contact with. Hence, hand hygiene is important to contain the spread of this virus.

In Singapore, we have not traced any of our transmission to gas pumps and shopping cart handles.

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Snopes also evaluated this claim and similarly rated it a mixture of true and false.

Health Feedback has produced a number of other claim reviews on COVID-19. You can view them here.

REFERENCES

• 1 – Cai et al. (2020) Indirect Virus Transmission in Cluster of COVID-19 Cases, Wenzhou, China. Emerging Infectious Disease.
• 2 – van Doremalen et al. (2020) Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. New England Journal of Medicine.
• 3 – Kampf et al. (2020) Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. Journal of Hospital Infection.
• 4 – Chin, et al. (2020) Stability of SARS-CoV-2 in different environmental conditions. medRxiv
• 5 – Moriarity et al. (2020) Public Health Responses to COVID-19 Outbreaks on Cruise Ships — Worldwide, February–March 2020. Morbidity and Mortality Weekly Report.
• 6 – Ansaldi et al. (2004) SARS CoV, influenza A and syncitial respiratory virus resistance against common disinfectants and ultraviolet irradiation. Journal of Preventive Medicine and Hygiene.