We know that people can become infected with viruses and germs simply by touching a surface that an infected person previously interacted with, but how long do germs last on these surfaces?
In general, germs don’t last for very long periods of time outside the human body. They are structurally quite weak and break down quickly in the harsh conditions of the outside world.
Additionally, how long they are detectable on a surface is different to how long they are infectious. To infect a new person, the virus has to be completely intact. When outside of the body, they quickly begin to degrade. So, even if the degraded virus makes its way inside the body, it won’t be able to do any harm.
How long they survive is dependent on a number of factors including the type of surface it lands on, the type of pathogen, and further environmental factors like humidity and temperature.
Some studies have been conducted to test how long viruses remain on various surface. The SARS and MERS viruses, which are both types of coronavirus, were shown to persist on average around 4-5 days on non-porous surfaces like glass, metal and plastic
It’s understood that viruses, bacteria and fungi last for shorter amounts of time on porous surfaces. Porous surfaces include any types pf fabric like carpets, clothing and bedding. Although, the exact amount of time depends on the specific fabric.
Influenza viruses were found to remain infectious on non-porous surfaces for only up to 9 hours. On porous surfaces, they lasted even less time, remaining infectious only for 4 hours.
Viruses prefer warm, humid environments which is why they often make their way into the human body through the throat and the nose. So, why do they last longer on non-porous surfaces which are generally hard and cold?
Porous fabrics are able to absorb moisture and actually suck moisture away from the virus, leaving it dry. The lack of moisture is what causes the virus structure to degrade.
This is how absorbent bed sheets are better for health than non-absorbent sheets. Having breathable bedding that wicks moisture away from the body creates a more hygienic sleeping environment. Any viruses that are introduced to the bedding will soon break down from dehydration.