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Terminology thread:
rate ≠ risk
infection ≠ disease
quarantine ≠ isolation
social distancing ≠ physical distancing
prolonged PCR positivity ≠ shedding
virulence ≠ transmissibility
References to follow
rate ≠ risk
infection ≠ disease
quarantine ≠ isolation
social distancing ≠ physical distancing
prolonged PCR positivity ≠ shedding
virulence ≠ transmissibility
References to follow
1/ rate ≠ risk
A risk is a probability of a harm (of a given magnitude)
A rate is something that varies over time https://journals.lww.com/epidem/Fulltext/2013/07000/Case_Fatality__Rate,_Ratio,_or_Risk_.23.aspx
A risk is a probability of a harm (of a given magnitude)
A rate is something that varies over time https://journals.lww.com/epidem/Fulltext/2013/07000/Case_Fatality__Rate,_Ratio,_or_Risk_.23.aspx
2.1/ infection ≠ disease
Many infections are asymptomatic or even beneficial!
An infectious disease only occurs when the host-pathogen interaction results in harm (i.e., a harmful disturbance of normal host function) https://link.springer.com/article/10.1007/s40592-020-00123-z
Many infections are asymptomatic or even beneficial!
An infectious disease only occurs when the host-pathogen interaction results in harm (i.e., a harmful disturbance of normal host function) https://link.springer.com/article/10.1007/s40592-020-00123-z
2.2/
For more on the fascinating but confusing terminology of infection and disease, see below
"Another factor contributing to imprecise use of the lexicon is that microbial factors are often held responsible for disease pathogenesis." https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(02)00398-5/fulltext
For more on the fascinating but confusing terminology of infection and disease, see below
"Another factor contributing to imprecise use of the lexicon is that microbial factors are often held responsible for disease pathogenesis." https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(02)00398-5/fulltext
2.3/ By the same authors:
"[Opportunistic infection in AIDS patients] revealed that available explanations for microbial infectiveness and virulence were flawed." https://bmcimmunol.biomedcentral.com/articles/10.1186/s12865-015-0076-1
"[Opportunistic infection in AIDS patients] revealed that available explanations for microbial infectiveness and virulence were flawed." https://bmcimmunol.biomedcentral.com/articles/10.1186/s12865-015-0076-1
3/ quarantine ≠ isolation
Quarantine is an intervention targeted at people exposed but not known to be infected
Isolation is an intervention targeted at people known to be infected
Of course, the liberty restrictions can be similar in both cases https://link.springer.com/article/10.1007/s40592-020-00123-z
Quarantine is an intervention targeted at people exposed but not known to be infected
Isolation is an intervention targeted at people known to be infected
Of course, the liberty restrictions can be similar in both cases https://link.springer.com/article/10.1007/s40592-020-00123-z
4/ social distancing ≠ physical distancing
"Social distance" is a term previously used for differences due to class and race
Public health should (arguably) never have used this term, since physical distance is what we need for infection control https://www.cabinetmagazine.org/kiosk/scherlis_lily_30_april_2020.php
"Social distance" is a term previously used for differences due to class and race
Public health should (arguably) never have used this term, since physical distance is what we need for infection control https://www.cabinetmagazine.org/kiosk/scherlis_lily_30_april_2020.php
5/ prolonged PCR positivity ≠ shedding
Prior to 2020, viral shedding was a term used when live virus was released from cells and from there sometimes to other people / hosts
PCR positivity often reflects the detection of dead viral fragments, not necessarily live virus
Prior to 2020, viral shedding was a term used when live virus was released from cells and from there sometimes to other people / hosts
PCR positivity often reflects the detection of dead viral fragments, not necessarily live virus
6/ virulence ≠ transmissibility
Virulence refers to the risk of an infection resulting in harm
Transmissibility is the likelihood of spread to one or more other hosts
For discussion of the complexities here, see again: https://bmcimmunol.biomedcentral.com/articles/10.1186/s12865-015-0076-1
Virulence refers to the risk of an infection resulting in harm
Transmissibility is the likelihood of spread to one or more other hosts
For discussion of the complexities here, see again: https://bmcimmunol.biomedcentral.com/articles/10.1186/s12865-015-0076-1
Happy for corrections, clarifications, or better references for any of these!
