Systemic Infection

Petri dishes

What is a systemic infection?

A systemic infection earns its name by being spread throughout the systems of the body. It can be compared to an infection where the pathogen or symptoms are localized in one area. Such infections are sometimes known as local infections. Systemic infections are not necessarily more severe than local infections. They just affect a larger proportion of the body. For example, the common cold is a systemic infection, but it is usually not particularly serious.

In contrast, a badly infected cut is serious but not necessarily systemic. (It could become systemic if the infection spread.) 

Not all systemic diseases are infections. For example diabetes causes symptoms and changes throughout the body. It is an autoimmune disorder that is not caused by an infection, and it is a systemic disease. Cardiovascular disease is also a systemic disease. Many types of cardiovascular disease are related to behavioral factors, genetics, and the natural processes of aging. Cardiovascular disease is not usually caused by infections, although it can be.

Often Confused With: Septicemia. Septicemia is not the same thing as systemic infection. That term refers to the presence of bacteria in the circulating blood. It can also refer to the presence of bacterial toxins in blood. However, the circulatory system is just one system of the body. A blood infection is not necessarily affecting multiple systems.


What STDs are always systemic infections? Which STDs can be systemic?

Several STDs are either always systemic infections or can become systemic infection. HIV, for example, is a disease of the whole body. The virus attacks the immune system. If untreated, it can lead to immunodeficiency. Fortunately, highly effective treatments are now available.

They can both keep the virus in check and reduce transmission of HIV to others. 

Gonorrhea on the other hand, is usually a local bacterial infection. However, it can become disseminated under certain circumstances. When it does become a systemic infection it causes different symptoms than localized gonorrhea. For example, it can cause a type of infectious arthritis. Local infections with gonnorhea are more likely to cause genital discharge, or a sore throat. Those symptoms depend on the location of the infection. Many local gonorrhea infections cause  no symptoms at all!

Chlamydia may seem like an obvious candidate to cause systemic infections. It can ascend to the uterus. It affects a variety of sites, including the eyes and the rectum. However, the specific type of chlamydia that causes genital infections is not generally thought to cause systemic infections. Other chlamydia types, however, may do so. For example, the systemic disease lymphogranuloma venereum (LGV) is caused by a type of chlamydia that spreads throughout the body.

Oddly, LGV infections behave more like syphilis than chlamydia. This is despite the fact that the bacteria that causes them is a type of chlamydia. 

Syphilis moves through various stages. Early syphilis starts out looking like a local infection. It causes a few, small sores. However, syphilis is fundamentally a systemic infection, spread throughout the body. That's particularly true for chronic syphilis. If left untreated, it will eventually affect numerous systems in the body.For example, latent syphilis can eventually lead to neurological problems. Systemic syphilis infections can even lead to death. However, death from syphilis is rare in adults, due to the availability of effective treatments. Serious syphilis infections are much more of a concern in infants. Undetected syphilis during pregnancy can be devastating. 


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