etiology


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

aetiology

, etiology
1. the study of the causes of diseases
2. the cause of a disease
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

etiology

or

aetiology

the study of causation, especially of diseases, social pathologies, etc. (e.g. Durkheim's Suicide, 1897).
Collins Dictionary of Sociology, 3rd ed. © HarperCollins Publishers 2000
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Etiology

 

the cause of disease; a branch of pathology that studies causality in medicine. Specific etiological factors are known for a number of diseases, for example, most infectious and parasitic diseases. The causative agent of tuberculosis is known definitively to be Mycobacterium ; that of tertian malaria is Plasmodium vivax. These microorganisms never cause diseases other than tuberculosis and malaria, and these diseases, in turn, cannot be caused by other pathogens. We speak in such cases of specific etiology in order to emphasize the unambiguous cause-and-effect relationship existing between the etiological factor and the disease.

An example of etiological relations of a different kind is Staphylococcus albus, which causes not only septic endocarditis but other diseases, for example, furuncle or pneumonia. Protrac-tic septic endocarditis may be caused by a variety of microbes, including Streptococcus viridans. This type of etiological relationship is called nonspecific. The presence of the etiological factor is usually necessary but not always sufficient for the disease to develop. The organism has to be somewhat susceptible to the pathogenic principle, and the total inevitability of disease under natural conditions is rare.

The pathogenicity of causative agents varies widely. It is very high in plague, cholera, smallpox, and measles. However, only a few persons develop tonsillitis in a “streptococcal environment.” Mycobacterium tuberculosis, the undisputed cause of tuberculosis, is present in the great majority of human beings, but only a few contract the disease. Its development, location, and severity are largely determined by individual reactivity. Thus, an infectious disease results from the interaction of a microbe and the human organism. Viruses, bacteria, and other living organisms are not the only definitively known causes of disease. Physical (including radiation) and chemical agents also cause injury.

The etiological role of the hereditary factors present in the organism at the cellular and molecular levels is incomparably more complex. Distortion of the genetic information underlying hereditary diseases can also be related justifiably to etiology and to the mechanism of development of disease (that is, pathogenesis), because the strictly etiological role belongs to those factors, often still obscure, that caused a mutation, for example, in the patient’s parents. Disease in individuals with a hereditary predisposition is interpreted differently, because such a predisposition creates only the conditions conducive to the development of disease. The disease is regarded in the chain of cause-and-effect relations as a pathogenetic rather than etiological factor.

With respect to an actual disease in a particular individual, the etiology is always related to a number of conditions either resisting or promoting the development of the disease. Therefore, the etiology may be considered separately from the pathogenesis only in connection with an analysis of it and not in an actual therapeutic and diagnostic situation. It is often difficult to distinguish the original cause of a disease among the many factors involved. The etiology of some human diseases has not been established, although the pathogenesis of several of them has been thoroughly studied and the diseases are regarded as independent nosologic entities. However, this cannot serve as a basis for denying the very existence of the original cause or for maintaining that there are many causes, as in chronic diseases whose etiology has not yet been discovered (tumors, peptic ulcer, atherosclerosis). Since the term “etiology” is usually applied only to the main cause of a disease and not to the mechanism of its development, symptoms, complications, and sequelae, we can speak, for example, of the allergic nature of some lung diseases but not of their allergic etiology.

It is of considerable practical importance to discover the etiology of a disease, because it pro vides a sound basis not only for pathogenetic and expectant treatment but also for specific action by therapeutic agents on the causative factor, for example, the use of antibiotics to treat infectious diseases. Determination of the etiology of a disease is also the basis for rational preventive measures (for example, vaccination against infectious diseases).

The term “etiology” is also used in veterinary medicine.

I. V. MARTYNOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

etiology

[‚ēd·ē′äl·ə·jē]
(medicine)
Any factors which cause disease.
(science and technology)
A branch of science dealing with the causes of phenomena.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Importance of this study can be recognized from the fact that study of etiology and possible outcomes in terms of mortality and morbidity of the patients could help in making recommendations for the clinicians.
The outbreaks of known infectious etiology were caused by a diverse array of chlorine-susceptible pathogens, including enteric bacteria, parasites, and viruses.
After undergoing amyloid PET, the suspected etiology changed for 25 percent of patients, more often due to a negative than a positive PET result (31 and 18 percent, respectively).
She believes that a systematic approach toward characterizing the tantrum will be helpful in understanding the underlying etiology and appropriate treatment.
The changing trend was influenced by individual lifestyles, risk factors, and etiology diagnostic techniques.
The most common stroke subtypes were large artery atherosclerosis (n=140; 59,6%), followed by small vessel disease (n=65,2;27,7%), undetermined etiology (n=23; 9,8%), cardioembolism (n=5;2,1%), and other determined etiology (n=2;0,9%).
All vasculitides with probable etiology were named as 'vasculitis associated with probable etiology' according to 2012 revised international Chapel Hill Consensus Conference on the nomenclature of vasculitides (CHCC 2012).2 Moreover, one patient had vasculitis associated with systemic disease which was a separate category in CHCC 2012 classification.
The etiology of ESRD was identified among 78% (n = 64) of patients and was distributed as follows: vascular renal disease (18.3%, n = 15), diabetic nephropathy (18.3%, n = 15), nondiabetic glomerulopathy (11%; n = 9), tubulointerstitial disease (11%; n = 9), and hereditary nephropathy (19.4%; n = 16).
This text contains 30 chapters detailing the etiology, prevention, and treatment of common and uncommon complications related to the diagnosis, treatment planning, placement, restoration, and maintenance of dental implants, as well as complications resulting from site development procedures, and medicolegal issues.