Young, C; Dalidowicz, M; Mueller, M. What is the period of communicability of symptomatic SARS-CoV-2? 2020 Apr 25; Document no.: INF042401-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 35 p. (CEST evidence search report)
The period of communicability of symptomatic SARS CoV-2 infections remains unclear.
Viral RNA shedding measured from the onset of illness is a common proxy used to estimate the period of communicability; however, confirmation of the viability of viral remnants in secretions through culture or other methods seldom occurs in practice.
Several factors including age, male sex and clinical severity influence individual variation in viral shedding and suggest the need for tailored control efforts.
Temporal patterns in viral shedding across different types of bodily secretions has implications for transmissibility and criteria for discontinuation of control measures during convalescence.
Williams-Roberts, H; Lee, S; Young, C; Dalidowicz, M; Mueller, M. What is the period of communicability of symptomatic SARS CoV-2? 2020 Apr 27; Document no.: INF042401 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 24 p. (CEST rapid review report)
McCarron, M; Lee, S; Takaya, S; Howell-Spooner, B; Dalidowicz, M. Is there increased morbidity or mortality peri-operatively for symptomatic, asymptomatic, post-COVID patients? 2020 Oct 15; Document no.: INF092801 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 27 p. (CEST rapid review report)
Miller, L; Fox, L. How is COVID-19 transmitted from person-to-person and what is the most common source of transmission? 2020 Dec 15; Document no.: INF121501-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 16 p. (CEST evidence search report)
· A recent evidence synthesis was completed by Public Health Ontario to answer a similar question. That synthesis has been deemed of sufficiently high quality and contains a recent enough evidence review to provide the necessary information to answer the question. Please refer to the attached document for the Key Points
· We have reviewed the literature identified by our search that has been published since the time of the literature review in the Public Health Ontario evidence synthesis (i.e., between Oct 14, 2020 and Dec 15, 2020). No significant changes to the Key Points are noted.
· Our team agrees with the conclusion of Public Health Ontario that the dominant mechanism of transmission is primarily through direct contact with respiratory droplets but that COVID-19 is an opportunistic airborne
Rapid Review Report: INF121501 RR (Version 1: December 17, 2020 17:30) 2
pathogen, where aerosol transmission occurs under the right combination of conditions (for instance a poorly ventilated space where a high volume of virus can be produced and concentrated).
Vanstone, J; Miller, L; Fox, L. How is COVID-19 transmitted from person-to-person and what is the most common source of transmission? 2020 Dec 15; Document no.: INF121501 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 11 p. (CEST rapid review report)
Vanstone, J; Miller, L; Fox, L. How is COVID-19 transmitted from person-to-person and what is the most common source of transmission? 2020 Dec 17; Document no.: INF121501 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. (CEST table)
Young, C; Howell-Spooner, B. What is the duration of immunity for COVID-19 in previously infected patients? 2020 Dec 29; Document no.: INF090101v3-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 39 p. (CEST evidence search report)
Howell-Spooner, B; Miller, L. What is the R0 (basic reproduction number) of the new coronavirus variant detected in the UK? 2020 Dec 31; Document no.: INF123001-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 8 p. (CEST evidence search report)
· First confirmed case of reinfection documented in a 33 year-old man in Hong Kong, who was first infected with the virus in March, and again while on holiday in Spain four and a half months later – though asymptomatic for both infections
· Genetic sequencing has identified a small number of reinfection cases with different strains
· No concrete evidence on the presence and/or duration of immunity to SARS-CoV-2 in humans
· Demonstration of PCR positivity does not necessarily indicate continued or renewed infection; it may indicate the presence of a dead virus.
· In-vitro analyses have documented the presence of SARS-CoV-2 antibodies in convalescent samples up to eight months post infection
· Only one small study in rhesus monkeys recovered from SARS-CoV-2 were not re-infected when re-challenged with SARS-CoV-2 upon recovery
· Many cases series of previously recovered SARS-CoV-2 patients re-testing positive following clinical and pathological recovery, but virus has been unable to be cultured from those patients, most remain asymptomatic and there have been no documented secondary cases arising from patients following positive re-tests
Badea, A; Lee, S; Groot, G; Takaya, S; Dalidowicz, M; Howell-Spooner, B. What is the duration of immunity for COVID-19 in previously infected patients? 2021 Jan 20; Document no.: INF090101v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 26 p. (CEST rapid review report)
