The germs are microorganisms that can cause infectionssuch as bacteria and viruses. Talking about how long they can survive in general is talking about something that is extremely difficult. There are pathogens that die practically instantly outside the human body, while others that can live minutes, hours, years and even centuries.
The survival time of pathogenic germs depends on the nature of the organism itself, but also on environmental conditions such as temperature, humidity, salinity and composition of the medium in which they are. Below we will see some examples of life times of viruses, bacteria and other types of germs.
How long can viruses survive?
In a strict sense, there are many doubts among the scientific community about whether viruses can be considered living organisms, in any case they would be a form of acellular life. Viruses tend to survive longer on solid non-porous surfaces and in environments of low sunlight, low humidity and low temperatures.
The flu virusfor example, you can stay active from one to several days on solid surfaces such as glass, plastic or metal, but only 5-15 minutes on hands. The flu virus can also survive in droplets suspended in the air for several hours, for example in droplets emitted by coughing or sneezing.
The call virus stomach flu and common cold They can also survive outside the body for up to several weeks on inert solid surfaces, although the infective capacity becomes very low at 24 hours, because it is not the same that they are still alive that they can infect. On the hands and other external tissues they only survive a few minutes. The rhinovirus, which is the most common in colds, can remain active for up to an hour on the skin.
The parainfluenza virus, which causes various respiratory tract infections, including laryngotracheobronchitis, can remain on non-porous surfaces for up to 10 hours. Respiratory syncytial virus, another virus related to flu-like respiratory infections, survives up to six hours on hard surfaces, 30 to 45 minutes on textiles, 20 minutes on the skin.
Herpes viruses survive up to two to three hours on the skin. HIV, luckily, dies almost instantly outside the body in contact with oxygen and sunlight. The smallpox virus almost completely disappears within 24 hours.
How long can bacteria survive?
Unlike viruses, which survive better on non-porous surfaces, bacteria prefer porous surfaces and, in general, they remain infectious for much longer than viruses.
How long bacteria survive outside the body depends on numerous external factors, their preferred conditions, and whether they are capable of developing resistance structures, especially spores.
Spores, fortunately for bacteria and unfortunately for the organisms they infect, can survive for long periods of time. For example, anthrax bacteria (Bacillus anthracis) can survive decadesand if conditions are right, up to several centuries.
Escherichia coli Y Salmonellatwo of the most common bacteria in food-borne infections, live for several hours outside the body, and can last up to one or two days, although if they are in contaminated food, the time is much longer, since they have adequate nutrients and conditions to develop.
Staphylococcus aureusone of the most common bacteria in skin wound infections and which can cause anaphylactic shock in certain circumstances, can form spores and survive for several weeks on clothing.
Other pathogens
Viruses and bacteria are not the only pathogenic germs for humans, so are fungi, protozoa and even some types of algae.
The fungal spores can survive decades and centuries in soil, several months in textile fabrics. Other fungi, such as molds and yeasts, on the contrary, die between 1 and 2 days in a dry environment, but their spores are practically everywhere and to prevent their growth, it is necessary to limit humidity.
Some protozoa can also develop resistance structures called cysts. The cysts are much more resistant than the spores of fungi and bacteria, but they can live for several months in the soil.
Prevention
One of the best measures to reduce the survival of bacteria, viruses, fungi and germs in general, is keep surfaces clean and dryso that the amount of moisture and nutrients available for growth is reduced.
- Use soap and water It is a basic and effective measure. Washing your hands helps prevent the spread and spread of germs.
- Disinfect surfaces with bleach and alcohol It is also an easy, effective and cheap way to disinfect household surfaces.
- If there are possibly infected fabrics and clothing, wash them with detergents and a temperature of 40-60 ºC and the use of dryers greatly reduces the survival time and ability of most types of germs.