If you had a look at the surfaces around you with the aid of a microscope, you would find that they were teeming with organisms. Our environment is full of living things we cannot see with the naked eye. Infectious diseases can be caused by a variety of dangerous organisms including bacteria and viruses. Collectively these organisms are known as germs. But how long do they live outside the body?
Viruses are generally shorter lived than bacteria because they must be inside a host to reproduce. They can survive for a while on exterior surfaces, but they can’t increase in numbers. Bacteria can reproduce on their own and can multiply anywhere that conditions are favorable. In less than twenty four hours one bacterial cell can turn into millions, and it only takes a few to make you sick.
Virus survival times vary widely. Some viruses such as HIV are very short-lived. HIV is fragile and can easily be killed by lack of moisture or strong light. On the other end of the spectrum is anthrax, which in its spore form can be incredibly difficult to destroy, as referenced in this Fox News article. Cold and flu viruses can survive from a few minutes to a couple days, depending on the surface, temperature, and humidity. Viruses tend to survive better on hard surfaces such as metal or plastic, and high humidity prolongs their lifespan.
Longevity for bacteria is different. Bacteria do not survive well on hard surfaces, but thrive on porous damp surfaces. You’ve probably heard about research indicating the huge numbers of bacteria present on things like kitchen sponges and dishcloths. These locations are ideal because they protect bacteria from strong light and dryness. Like human organisms, bacteria need water to survive. In the right environment, bacteria can live for months.
Most infections, both viral and bacterial, are picked up on our hands. We touch hundreds of surfaces in the course of a day. This is why experts reinforce the importance of regular, thorough hand washing several times per day. Secondly, we tend to touch our mouths, eyes, and noses often during the day. These areas have mucous membranes that are ideal depositories for germs. If you can make a conscious effort to keep your hands away from these areas, especially if you have been around someone who is sick, you will reduce your chances of infection.
If you focus your cleaning efforts on surfaces that are touched constantly, you can eliminate a significant number of germs from your surroundings. Things like door knobs, cabinet handles, faucets, and telephones are prime targets. You can download a hygiene standards booklet from the Hygiene Council, with lots of good information and advice.
Regardless of how long germs live, controlling their presence in your environment is the best thing you can do to keep yourself and your family healthy.