Objectives: To summarise the evidence on the duration of infectiousness of individuals in whom SARS-CoV-2 ribonucleic acid is detected. Methods: A rapid review was undertaken in PubMed, Europe PubMed Central and EMBASE from 1 January 2020 to 26 August 2020. Results: We identified 15 relevant studies, including 13 virus culture and 2 contact tracing studies. For 5 virus culture studies, the last day on which SARS-CoV-2 was isolated occurred within 10 days of symptom onset. For another 5 studies, SARS-CoV-2 was isolated beyond day 10 for approximately 3% of included patients. The remaining 3 virus culture studies included patients with severe or critical disease; SARS-CoV-2 was isolated up to day 32 in one study. Two studies identified immunocompromised patients from whom SARS-CoV-2 was isolated for up to 20 days. Both contact tracing studies, when close contacts were first exposed greater than 5 days after symptom onset in the index case, found no evidence of laboratoryconfirmed onward transmission of SARS-CoV-2. Conclusion: COVID-19 patients with mild-to-moderate illness are highly unlikely to be infectious beyond 10 days of symptoms. However, evidence from a limited number of studies indicates that patients with severe-to-critical illness or who are immunocompromised, may shed infectious virus for longer .

Mass gatherings play an important role in society, but since the onset of the Covid-19 pandemic, they have generally been restricted in order to mitigate transmission of SARS-CoV-2. The aim of this study was to summarise the evidence regarding the effectiveness of public health measures at preventing the transmission of SARS-CoV-2 at mass gatherings, and hence inform guidance on the organisation of these events. A rapid review was undertaken in Cochrane, Embase (OVID), Medline (OVID), Google, Web of Science and Europe PMC from 1 January 2020 to 3 June 2021. Of the identified 1,624 citations, 14 articles referring to 11 unique studies were included. This rapid review found evidence from 11 studies (involving approximately 30,482 participants) that implementing a range of measures may reduce the risk of SARS-CoV-2 transmission at mass gatherings; however, it is unlikely that this risk can be eliminated entirely. All studies adopted a layered mitigation approach involving multiple measures, which may be more effective than relying on any single measure. The number and intensity of measures implemented varied across studies, with most implementing resource intense measures. Importantly, all included studies were only of 'fair' to 'poor' quality. In conclusion, there is currently limited evidence on the effectiveness of measures to prevent SARS-CoV-2 transmission at mass gatherings. As mass gatherings recommence, continued adoption of known mitigation measures is required to limit the risk of transmission, as well as ongoing research and surveillance to monitor the potential impact of these events on the wider population and healthcare system.

​Summary This rapid review aimed to identify measures available to support those in isolation or quarantine during the coronavirus disease 2019 (Covid‐19) pandemic, and determine their effectiveness in improving adherence to these recommendations and or reducing transmission. The rapid review consisted of two elements, the first was a review of guidance published by national and international agencies relating to measures to support those in isolation (due to case status) or quarantine (due to close contact status) during the Covid‐19 pandemic. Five categories of support measures were identified in the international guidance, they were: Psychological, addiction and safety supports, Essential supplies, Financial aid, Information provision and Enforcement. The second element was a rapid literature review of the effectiveness of measures used to support individuals in isolation or quarantine during any pandemic or epidemic setting, due to respiratory pathogens. A systematic search of published peer‐reviewed articles and nonpeer‐reviewed pre‐prints was undertaken from 1 January 2000 to 26 January 2021. Two Australian publications met the inclusion criteria, both based on data from a survey undertaken during the 2009 H1N1 pandemic. The first reported that 55% of households were fully compliant with quarantine recommendations, and that there was increased compliance reported in households that understood what they were meant to do compared with those who reported that they did not (odds ratio [OR]: 2.27, 95% confidence interval [CI]: 1.35–3.80). The second reported that access to paid sick and or carer's leave did not predict compliance with quarantine recommendations (OR: 2.07, 95% CI: 0.82–5.23). Neither reported on reduction in transmission.

Rapid antigen detection tests (RADTs) offer advantages over gold‐standard reverse transcription polymerase chain reaction (RT‐PCR) tests in that they are cheaper and provide faster results, thus enabling prompt isolation of positive SARS‐CoV‐2 cases and quarantine of close contacts. The aim of this study was to collate and synthesise empirical evidence on the effectiveness of rapid antigen testing for the screening (including serial testing) and surveillance of asymptomatic individuals to limit the transmission of SARS‐CoV‐2. A rapid review was undertaken in MEDLINE (EBSCO), EMBASE (OVID), Cochrane Library, Europe PMC and Google Scholar up until 19 July 2021, supplemented by a grey literature search. Of the identified 1222 records, 19 reports referring to 16 studies were included. Eight included studies examined the effectiveness of RADTs for population‐level screening, four for pre‐event screening and four for serial testing (schools, a prison, a university sports programme and in care homes). Overall, there is uncertainty regarding the effectiveness of rapid antigen testing for the screening of asymptomatic individuals to limit the transmission of SARS‐CoV‐2. This uncertainty is due to the inconsistent results, the relatively low number of studies identified, the predominantly observational and/or uncontrolled nature of the study designs used, and concerns regarding methodological quality. Given this uncertainty, more real‐world research evidence in relevant settings, which is of good quality and timely, as well as economic evaluation, is required to inform public policy on the widespread use of RADTs in asymptomatic individuals.

Summary The aim of this rapid review was to determine the effectiveness of pharmacological interventions (excluding vaccines) to prevent coronavirus disease 2019 (Covid‐19) or reduce the severity of disease. A systematic search of published peer‐reviewed articles and non‐peer‐reviewed pre‐prints was undertaken from 1 January 2020 to 17 August 2021. Four randomised controlled trials (RCTs) and one non‐RCT were included; three trials (two RCTs and one non‐RCT) tested ivermectin with or without carrageenan. While all reported some potential protective effect of ivermectin, these trials had a high risk of bias and the certainty of evidence was deemed to be ‘very low’. One RCT tested bamlanivimab compared to placebo and reported a significantly reduced incidence of Covid‐19 in the intervention group; this trial had a low risk of bias however the certainty of evidence was deemed ‘very low’. The fifth RCT tested casirivimab plus imdevimab versus placebo and reported that the combination of monoclonal antibodies significantly reduced the incidence of symptomatic and asymptomatic SARS‐CoV‐2 infection, viral load, duration of symptomatic disease and the duration of a high viral load; this trial was deemed to have a low risk of bias, and the certainty of evidence was ‘low’. The designations ‘low' and ‘very low’ regarding the certainty of evidence indicate that the estimate of effect is uncertain and therefore is unsuitable for informing decision‐making. At the time of writing, there is insufficient high quality evidence to support the use of pharmacological interventions to prevent Covid‐19.