The human skin is home to a whole world: up to 100,000 microorganisms inhabit every square centimeter. Most of them are harmless, and some are even necessary for maintaining a normal microbial balance. However, there are also those that can cause diseases.
When a person sneezes, tiny droplets containing viruses and bacteria can travel nearly a meter. Once on surfaces, microbes can survive there for quite a while — it all depends on their type and environmental conditions.
Why Viruses and Bacteria Live Differently
Viruses cannot exist independently: they need to enter the cells of a living organism to reproduce. Therefore, they do not live long outside their host. Bacteria, on the other hand, are structured differently — they can divide outside of the host's body, allowing them to survive significantly longer.
The lifespan of microbes is influenced by temperature and humidity. None can withstand a dry environment where humidity is below 10%. However, where there is nourishment — food particles, droplets of mucus, skin cells — microorganisms thrive and multiply actively. This is why a kitchen sponge is one of the "dirtiest" places in the house.
How Long Different Microbes Live
Mesophilic bacteria — those that prefer room temperature — live the longest. This includes, for example, the Koch bacillus, which causes tuberculosis.
· Escherichia coli can survive from several hours to a day under normal humidity and room temperature. It is often found in raw meat and can cause food poisoning.
· Calicivirus, the causative agent of intestinal flu, survives from several days to several weeks.
· However, HIV dies almost instantly in the external environment.
Some bacteria have the remarkable ability to survive adverse conditions. They form spores — dense shells that protect them from heat, cold, and dryness.
The Most Resilient Microorganisms
For example, Staphylococcus aureus, which causes food poisoning and purulent infections, can exist on dry clothing for weeks, feeding on micro-particles of skin. Moreover, the spores of the anthrax bacillus can survive in the soil for decades — their viability is measured not in years, but in centuries.
How to Protect Yourself from Microbes
There is no need to be afraid. It is impossible to completely eliminate microbes, nor is it necessary — many of them are harmless. However, to reduce the risk of infection, it is enough to follow simple rules:
· wash your hands with soap more often, especially after being outdoors and contact with animals;
· regularly disinfect surfaces that you frequently touch — door handles, kitchen tables, sinks;
· do not leave damp sponges and cloths — bacteria multiply quickly in them.
