Infection Information & Infection Links at HealthHaven.com

For other uses, see Infection (disambiguation).

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, 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.^[1]

[edit] Primary and secondary

Primary and secondary infection may either refer to succeeding infections or different stages of one and the same infection such as in acute herpes labialis infection.

In the latter case, acute infection may also be used, as in acute HIV infection.

[edit] Colonization

Wound colonization refers to nonreplicating microorganisms within the wound, while in infected wounds replicating organisms exist and tissue is injured. All multicellular organisms are colonized to some degree by extrinsic organisms, and the vast majority of these exist in either a mutualistic or commensal relationship with the host. An example of the former would be the anaerobic bacteria species which colonize the mammalian colon, and an example of the latter would be the various species of staphylococcus which exist on human skin. Neither of these colonizations would be considered infections. The difference between an infection and a colonization is often only a matter of circumstance. Organisms which are non-pathogenic can become pathogenic under the right conditions, and even the most virulent organism requires certain circumstances to cause a compromising infection. Some colonizing bacteria, such as Corynebacteria sp. and viridans streptococci, prevent the adhesion and colonization of pathogenic bacteria and thus have a symbiotic relationship with the host, preventing infection and speeding wound healing.

The variables involved in the outcome of a host becoming inoculated by a pathogen and the ultimate outcome include:

the route of entry of the pathogen and the access to host regions that it gains
the intrinsic virulence of the particular organism
the quantity or load of the initial inoculant
the immune status of the host being colonized

As an example, the staphylococcus species present on skin remain harmless on the skin, but, when present in a normally sterile space, such as in the capsule of a joint or the peritoneum, will multiply without resistance and create a huge burden on the host.

[edit] Occult infection

An occult infection is medical terminology for a "hidden" infection, that is, one which presents no symptoms. Dr. Fran Giampietro discovered this type, and coined the term "occult infection" in the late 1930s. Another word for an infection with no symptoms is "asymptomatic".

[edit] Bacterial or viral

Bacterial and viral infections can both cause symptoms such as malaise, fever, and chills. It can be difficult to distinguish which is the cause of a specific infection. ^[2] It's important to distinguish, because viral infections cannot be cured by antibiotics.

Comparison of viral and bacterial infection
Characteristic	Viral	Bacterial
Typical symptoms	In general, viral infections are systemic. This means they involve many different parts of the body or more than one body system at the same time; i.e. a runny nose, sinus congestion, cough, body aches etc. They can be local at times as in viral conjunctivitis or "pink eye" and herpes. Only a few viral infections are painful, like herpes. The pain of viral infections is often described as itchy or burning.^[2]	The classic symptoms of a bacterial infection are localized redness, heat, swelling and pain. One of the hallmarks of a bacterial infection is local pain, pain that is in a specific part of the body. For example, if a cut occurs and it is infected with bacteria, pain will occur at the site of the infection. Bacterial throat pain is often characterised by more pain on one side of the throat. An ear infection is more likely to be bacterial if the pain occurs in only one ear.^[2] An infection that produces pus is not always bacterial.^{[citation needed]}
Cause	Pathogenic viruses	Pathogenic bacteria

[edit] See also

Antiseptic
Autoinfection
Hand infection
List of infectious diseases
Infectious diseases
Multiplicity of infection
Staphylococcus aureus
Ubi pus, ibi evacua (Latin: "where there is pus, there evacuate it")
Routes of infections

[edit] References

^ Nursing Pharmacology Made Incredibly Easy. Lippincott Williams & Wilkins. 2009.p.483]]
^ ^a ^b ^c Bacterial vs. Viral Infections - Do You Know the Difference? National Information Program on Antibiotics

Vaccine Research Center Information concerning vaccine research clinical trials for Emerging and re-Emerging Infectious Diseases.
aboutinfections.com

[0] Nursing Pharmacology Made Incredibly Easy. Lippincott Williams & Wilkins. 2009.p.483]]

[nipa-1] Bacterial vs. Viral Infections - Do You Know the Difference? National Information Program on Antibiotics

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