How long does the flu live on surfaces?

‘Tis the season for cooler temperatures, shorter days and cozy nights by the fire. Unfortunately, this time of year is also the start of flu season, which typically lasts from October to May.

The flu spreads primarily through respiratory droplets that become airborne when an infected person coughs, sneezes, or even talks. But the flu doesn’t simply spread from person to person through the air. These tiny droplets can land on surfaces, and you can catch the flu by touching objects contaminated with the influenza virus and then touching your mouth, nose, or eyes.

“These surfaces, like countertops, doorknobs or your keyboard, can harbor the influenza virus for up to 48 hours depending on the environment and spread it to others,” says Stanley Martin, MD, an infectious disease physician at Geisinger. “You can’t avoid every place where germs hide, but you can take precautions to better protect yourself from surface transmission this season.”

How long does the flu survive on surfaces?

Flu viruses can remain infectious on surfaces for different lengths of time depending on several factors.

“Fortunately, the influenza virus cannot withstand the harsh environmental conditions outside the human body and quickly loses strength,” says Dr. Martin. “So the longer the virus stays on a surface, the lower the risk of contracting the flu through contact alone.”

temperature

Low temperatures can extend the survival of the flu virus, while high temperatures tend to shorten its lifespan. Inside the body, warm temperatures melt the virus’s protective outer shell, allowing it to infect other cells. However, when it melts outside the body in warm temperatures, the virus is vulnerable to the elements and becomes weaker.

humidity

In dry air with low humidity, the flu virus can become airborne and spread more easily via respiratory droplets. However, when humidity is high, there are more water molecules in the air, which interfere with transmission.

Type of surface

Influenza viruses tend to survive longer on hard, non-porous surfaces than on porous surfaces. Research shows that both influenza A and influenza B viruses survive for 24 to 48 hours on hard surfaces such as stainless steel, doorknobs and plastic, but for less than 12 hours on fabric, paper and tissues.

“Once the virus is transferred to the hands, the lifespan is significantly shortened and it is only contagious for about five minutes,” says Dr. Martin. “But if you consider how often you itch your nose, rub your eyes or shake hands, even that is still enough time to spread the virus.”

Common surfaces where flu pathogens can be found

Shared objects or surfaces in high-traffic or frequently touched areas are a popular breeding ground for germs. Unfortunately, some are less obvious and aren’t cleaned as often as they should to keep flu pathogens away, such as:

• Mobile phones and tablets
• Computer keyboards and mice
• TV remote controls
• Countertops
• Light switch
• Appliance handles and door handles
• toy
• Paper money
• Shopping cart
• Checkout keyboards in shops or restaurants
• Subway poles

“People are usually careful about germs in public spaces, but we also need to be careful about germs in our homes,” says Dr. Martin. “Germs that we come into contact with in public spaces can travel home with us.”

Preventing the spread of the flu

When it comes to flu prevention, it is important to focus not only on person-to-person transmission, but also on surface transmission.

To protect yourself from a bout of flu this season, Dr. Martin these measures:

• Practice good hand hygiene. Wash your hands often with soap and warm water for at least 20 seconds. If a sink is not available, use an alcohol-based hand sanitizer.
• Cover coughs and sneezes. Use a tissue or the inside of your elbow when coughing and sneezing. Be sure to throw away the tissue immediately.
• Avoid touching your face. The mouth, nose and eyes are entry points for the flu virus. You can catch the flu if your hands are contaminated and you touch your face.
• Disinfect frequently touched surfaces regularly. For effective use, be sure to follow the product instructions. For example, some require that a surface remain wet for at least 30 seconds to disinfect. Additionally, wash bedding and towels in hot water and tumble dry on high heat to kill germs.
• Use a humidifier. Running a humidifier at home or on the go will add moisture back into the air and can limit the transmission of the flu virus.
• Get the flu vaccine. Your best protection against the flu is an annual vaccination.

“The flu vaccine protects against the most common strains of the flu virus and reduces the severity of symptoms if infected,” says Dr. Martin. “Most people should get an annual flu shot because the virus can mutate and new strains can emerge each year.”

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