GC: n.

S: JSTOR – https://www.jstor.org/stable/1593118?seq=1#metadata_info_tab_contents (last access: 28 October 2020 ); WHO – https://apps.who.int/iris/bitstream/handle/10665/263163/PMC2476236.pdf?sequence=1&isAllowed=y (last access: 31 October 2020).

N: 1. Early 15c., “incidental matter,” from Middle French incidence (15c.), from Late Latin incidentia, from incidere “to happen, befall”. Meaning “act of coming into contact with or affecting” is from 1650s. In physics, of rays of light, etc., considered with reference to direction, from 1620s.
2. Number of individuals who develop a specific disease or experience a specific health-related event during a particular time period.
3.  If, over the course of one year, five women are diagnosed with breast cancer, out of a total female study population of 200 (who do not have breast cancer at the beginning of the study period), then we would say the incidence of breast cancer in this population was 0.025. (or 2,500 per 100,000 women-years of study).
4. According to TERMIUM PLUS, “incidence” has multiple meanings depending on the field of application. This term was standarized by the Health Technology Assessment (HTA) Glossary English Editorial Board and the Translation Bureau.
5. Incidence is often expressed as a ratio, in which the number of cases is the numerator and the population at risk is the denominator. The “incidence rate” is stricto sensu the number of new cases of disease related to the average population at a particular period of time …

S: 1. OED – https://www.etymonline.com/search?q=INCIDENCE (last access: 28 October 2020 ). 2. HSPH – https://www.hsph.harvard.edu/obesity-prevention-source/prevalence-incidence/ (last access: 28 October 2020). 3. DHNY – https://www.health.ny.gov/diseases/chronic/basicstat.htm (last access: 28 October 2020 ). 4. TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=incidence&codom2nd_wet=1#resultrecs ; https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=incidence+rate&codom2nd_wet=1#resultrecs (last access: 28 October 2020).

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S:

CR: coronavirus, COVID-19, disease, virus.