An infection happens when a foreign organism enters a person’s body and causes harm.
The organism uses that person’s body to sustain itself, reproduce, and colonize. These infectious organisms are known as pathogens. Examples of pathogens include bacteria, viruses, fungi, and prions. Pathogens can multiply and adapt quickly.
Some infections are mild and barely noticeable, but others are severe and life-threatening, and some are resistant to treatment. Infection can be transmitted in a variety of ways.
These include skin contact, bodily fluids, contact with feces, airborne particles, and touching an object that an infected person has also touched. How an infection spreads and its effect on the human body depend on the type of agent.
The immune system is an effective barrier against infectious agents, but colonies of pathogens may grow too large for the immune system to fight. At this stage, infections become harmful.
Many pathogens give off toxins that trigger negative responses from the body.
Types of infection
Bacteria, viruses, fungi, protozoa, parasites, and prions are different types of pathogen. They vary in their size, shape, function, genetic content, and how they act on the body.
For example, viruses are smaller than bacteria and they can enter a host and take over cells. However, bacteria can survive without a host.
Treatment will depend on the type of pathogen. This article will focus on the most common and deadly types of infection: bacterial, viral, fungal, and prion.
There are other infections that can have an effect on the body.
A single-celled organism with a nucleus can cause a protozoan infection. Protozoa commonly show features similar to animals, such as mobility, and can survive outside of the human body. They are most commonly transferred by contact with feces.
When they enter the human body, protozoa can also cause infection. Amebic dysentery is an example of a protozoan infection.
Helminths are larger, multicellular organisms that tend to be visible to the naked eye when full-grown. This type of parasite includes flatworms and roundworms. These are also able to infect the human body.
Finally, ectoparasites such as mites, tics, lice, and fleas can cause infection by attaching or burrowing into the skin.
The term can also include blood-sucking arthropods such as mosquitos that transmit infection by consuming human blood.
There is no single way to prevent all infectious diseases, but the following tips can reduce the risk of transmission:
Wash your hands often, especially before and after preparing food and after using the bathroom.
Clean every surface areas and avoid leaving room-temperature food exposed when cooking.
Receive any recommended vaccinations, and keep them up to date.
Only take antibiotics when prescribed, and be sure to complete any recommended course even if symptoms improve earlier than anticipated.
Disinfect rooms where there may be high concentrations of bacteria, such as the kitchen and bathroom.
Practice safe sex by receiving regular STD checks, using condoms, or abstaining altogether.
Avoid sharing personal items such a toothbrushes, combs, razorblades, drinking glasses, and kitchen utensils.
Follow a doctor’s advice about travelling or working when you are ill, as you could infect others.