'''Host factor '''(sometimes known as risk factor)<ref name=":0">{{Cite web |date=2021-12-20 |title=Principles of Epidemiology {{!}} Lesson 1 - Section 8 |url=https://www.cdc.gov/csels/dsepd/ss1978/lesson1/section8.html |access-date=2023-01-30 |website=www.cdc.gov |language=en-us}}</ref> is a medical term referring to the traits of an individual person or animal that affect susceptibility to disease, especially in comparison to other individuals.<ref>{{Cite web |title=Host factors |url=https://medical-dictionary.thefreedictionary.com/Host+factors |access-date=2023-01-30 |website=TheFreeDictionary.com}}</ref> The term arose in the context of infectious disease research, in contrast to "organism factors", such as the virulence and infectivity of a microbe. Host factors that may vary in a population and affect disease susceptibility can be innate or acquired.
Some examples: <ref name=":0" /> *general health *psychological characteristics and attitude *nutritional state *social ties *previous exposure to the organism or related antigens *haplotype or other specific genetic differences of immune function *substance abuse *race
The term is now used in oncology and many other medical contexts related to individual differences of disease vulnerability.
== See also == * Vulnerability index * Epidemiology * Immunology
== References == {{reflist}}
{{DEFAULTSORT:Host Factor}} Category:Animal diseases Category:Medical terminology
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