Noun

Singular infection

Plural infections

infection (plural infections)

1. (pathology) The act or process of infecting.
2. An uncontrolled growth of harmful microorganisms in a host.

Derived terms

• spurious infection

French

Noun

infection f. (plural infections)

1. (pathology) infection

Interlingua

Noun

Singular infection

Plural infectiones

infection (plural infectiones)

1. (pathology) The act or process of infecting.

An infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the host and can lead to chronic wounds, gangrene, loss of an infected limb, and even death. The host's response to infection is inflammation. Colloquially, a pathogen is usually considered a microscopic organism though the definition is broader, including parasites, fungi, viruses, prions, bacteria, and viroids. A symbiosis between parasite and host, whereby the relationship is beneficial for the former but detrimental to the latter, is characterised as parasitism. The branch of medicine that focuses on infections and pathogens is infectious disease. "When infection attacks the body, anti-infective drugs can help turn the tide of battle. Four types of anti-infective drugs exist: antibacterial, antiviral, antitubercular, and antifungal.

Many individuals develop a variety of infections but quickly overcome them. However, some individuals develop chronic or persistent infections. In the majority of cases, persistent infections are caused by viruses and not bacteria. The common viruses that can cause chronic infection include measles, hepatitis, various prion infections that affect the brain (mad cow), herpes, infectious mononucleosis and Cytomegalovirus (CMV). Bacteria can also cause chronic infections in individuals with diabetes, those with compromised immunity and in individuals who smoke.