Search results
Results from the WOW.Com Content Network
The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can cause disease. These small organisms, which are too small to be seen without magnification, invade humans, other animals, and other living hosts. Their growth and reproduction within their ...
The inception of a disease is not a firmly defined concept. [1] The natural history of a disease is sometimes said to start at the moment of exposure to causal agents. [2] Knowledge of the natural history of disease ranks alongside causal understanding in importance for disease prevention and control.
Specificity: Causation is likely if there is a very specific population at a specific site and disease with no other likely explanation. The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.
The following outline is provided as an overview of and topical guide to concepts related to infectious diseases in humans.. Infection – transmission, entry/invasion after evading/overcoming defense, establishment, and replication of disease-causing microscopic organisms (pathogens) inside a host organism, and the reaction of host tissues to them and to the toxins they produce.
A secondary disease is a disease that is a sequela or complication of a prior, causal disease, which is referred to as the primary disease or simply the underlying cause . For example, a bacterial infection can be primary, wherein a healthy person is exposed to bacteria and becomes infected, or it can be secondary to a primary cause, that ...
Koch's postulates (/ k ɒ x / KOKH) [2] are four criteria designed to establish a causal relationship between a microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884, based on earlier concepts described by Jakob Henle, and the statements were refined and published by Koch in 1890. [3]
A 2022 statement from the World Health Organization (WHO), defines the term this way: “Disease X is [used] to indicate an unknown pathogen that could cause a serious international epidemic.”
In medicine, the etiology of an illness or condition refers to the frequent studies to determine one or more factors that come together to cause the illness. Relatedly, when disease is widespread, epidemiological studies investigate what associated factors, such as location, sex, exposure to chemicals, and many others, make a population more or ...