infectivity

noun
in·​fec·​tiv·​i·​ty | \ (ˌ)in-ˌfek-ˈti-və-tē How to pronounce infectivity (audio) \
plural infectivities

Definition of infectivity

: the ability to produce or transmit infection : the quality or state of being infective The onset of cough on the second day of illness in this patient, followed by clinical evidence of pneumonia four days later, raised the question of his infectivity during the four days before hospitalization.— B. Johnson et al. Even when there are apparently high levels of the virus in the blood, there may be much less infectivity. … a thousand or more of these particles are needed to produce infection.— Charles Marwick specifically : the capacity to spread from host to host The swine flu's infectivity is rated at about 2.5, meaning that every infected person can spread the infection to 2.5 people and it doesn't take a math major to understand that implication. — Dennis Bloomfield

First Known Use of infectivity

1871, in the meaning defined above

History and Etymology for infectivity

infective + -ity

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Time Traveler for infectivity

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The first known use of infectivity was in 1871

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Last Updated

20 Jan 2021

Cite this Entry

“Infectivity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infectivity. Accessed 6 Mar. 2021.

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More Definitions for infectivity

infectivity

noun
in·​fec·​tiv·​i·​ty | \ ˌin-ˌfek-ˈtiv-ət-ē How to pronounce infectivity (audio) \
plural infectivities

Medical Definition of infectivity

: the quality of being infective : the ability to produce or transmit infection When sporozoites are incubated with serum from the protected animals, their infectivity is neutralized and prominent deposits of antibody appear over the surface of the parasite …— Louis H. Miller et al., Science The onset of cough on the second day of illness in this patient, followed by clinical evidence of pneumonia four days later, raised the question of his infectivity during the four days before hospitalization.— B. Johnson et al., The Journal of the American Medical Association specifically : the capacity to spread from host to host The swine flu's infectivity is rated at about 2.5, meaning that every infected person can spread the infection to 2.5 people and it doesn't take a math major to understand that implication. — Dennis Bloomfield, Staten Island (New York) Advance

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