Covid-19 RADAR

(Research Action Digest And Review)

Welcome to the COVID-19 RADAR from Public Health Suffolk


  • summarises COVID-19 related research evidence, published in the previous week, that is relevant to the Suffolk system,
  • makes recommendations for consideration, and
  • aims to ensure research evidence is rapidly disseminated and turned into local action.

Our approach will be to include "need to know" research and not "nice to know". We will not be including research specific to NHS healthcare as this is covered elsewhere, including nationally.

Key sources of information include (but are not limited to) the following peer-reviewed journals and websites:

Each article we include has been given a grading level based on GRADE. This is an internationally recognised grading system used by the American Medical Association and Cochrane Library for consistency in grading evidence.  Articles are graded for quality of evidence and strength of recommendation:

Quality of evidence: definitions

  1. High quality: further research is very unlikely to change our confidence in the estimate of effect.
  2. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
  3. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
  4. Very low quality: any estimate of effect is very uncertain.

Strength of recommendations: definitions

  1. Strong: the desirable effects of an intervention clearly outweigh the undesirable effects, or clearly do not, guideline panels offer strong recommendations.
  2. Weak: low quality evidence or evidence that suggests desirable and undesirable effects are closely balanced.

The findings are summarised below. Public Health Suffolk will work with colleagues to support them in getting the research into practice so that we can make a real difference collectively. Please send any research articles you want to be included in the COVID-19 RADAR to

COVID-19 RADAR team – Nowreen Azim, P Badrinath, Anna Crispe, Alison Matthews, Jeptepkeny Ronoh.

Radar 19 - 8 August 2020


Quality of Evidence:  Moderate                                            

Strength of Recommendation: Strong

What was the study about?

  • One of the first perspectives to discuss and support the theory of viral inoculum which suggests that universal masking may also reduce the amount of virus in the air—potentially leading to milder or even asymptomatic infections.
  • Objective: To discuss the hypothesis that universal masking reduces the “inoculum” or dose of the virus for the mask-wearer, leading to more mild and asymptomatic infection manifestations
  • Location: USA

What were the key findings?

  • There are two likely reasons for the effectiveness of facial masks: The first—to prevent the spread of viral particles from asymptomatic individuals to others—has received a great deal of attention. However, the second theory—that reducing the inoculum (the amount of virus particles in any exposure) of virus to which a mask-wearer is exposed will result in milder disease.
  • The study suggests that if everyone wears masks, these reduced exposures to the virus could lead to greater community-level immunity and slow the spread of COVID-19 until an effective vaccine is developed. Some evidence they state to support this theory is:
    • One recent model showed that population-level masking is one of the most efficacious interventions to reduce further spread of SARS-CoV-2, allowing for less-stringent lock-down requirements in countries adopting this strategy.
    • In a frequently cited study showing that hamsters are less likely to contract SARS-CoV-2 infection with a surgical mask partition, those hamsters that did contract COVID-19 with simulated masking had milder manifestations of infection.
    • A report from a paediatric haemodialysis unit in Indiana, where all patients and staff were masked, demonstrated that staff rapidly developed antibodies to SARS-CoV-2 after exposure to a single symptomatic patient with COVID-19. In the setting of masking, however, none of the new infections was symptomatic.
    • A case study of a ship in Argentina, where mask wearing was mandatory for passengers and the staff had N95 masks, more than 85% of people who got COVID-19 had asymptomatic infections.
    • Kai et al showed a correlation between population-level masking and number of COVID-19 cases in various countries, but an even stronger correlation with suppression of COVID-related death rates.
  • Exposing society to SARS-CoV-2 without the unacceptable consequences of severe illness could lead to greater community-level immunity and slow down spread as we await a vaccine.
  • This perspective puts forth another advantage of population-level facial masking for pandemic control with SARS-CoV-2 based on an old but enduring theory regarding viral inoculum, clinical manifestations in the host, and protection.

Actions and issues from this study for local consideration?

  • Whilst this study looks at the benefits of face coverings at a different perspective, it further  reiterates why universal public masking during the COVID-19 pandemic is an important pillar of disease control and face covering guidelines in the UK should be strictly adhered to.  

Recommended action for: Suffolk Health Protection Board, Communication team


Use of facemasks during the COVID-19 pandemic

  • H. J. Schünemann et al
  • Lancet Respiratory Medicine
  • 3rd August 2020
  • Quality of Evidence:  Very low
  • Strength of Recommendation: Weak

What was the study about?

  • Review of evidence and advice on wearing facemasks
  • Objective: Review evidence and make recommendations on wearing facemasks
  • Location: Global

What were the key findings?

  • People are infectious for at least 48 hours before symptom onset (presymptomatic), that some people have only minor symptoms (paucisymptomatic), and others remain entirely asymptomatic. These individuals can transmit the virus without knowing they are infectious—the main argument for use of facemasks as a source control.
  • Systematic reviews of facemask use suggest relative risk (RR) reductions for infection ranging from 6–80%, including for betacoronavirus infection (eg, COVID-19, SARS, MERS). For COVID-19, this evidence is of low or very low certainty.
  • In a setting with high baseline risks, such as health-care workers caring for a superspreading patient with COVID-19, wearing a mask prevents the infection in up to one out of two health-care workers, and a strong recommendation that all such individuals should wear a facemask might be warranted.
  • It is not yet clear where the exact threshold is for the baseline risk that justifies using facemasks in the community (or mandating them), but given the paucity of evidence for severe adverse effects that more invasive interventions have, wearing a facemask might be acceptable in many situations, despite the need for more evidence.
  • There is evidence of beneficial effects in medical mask studies, and such effects might also exist for optimally designed cloth masks, although the direct evidence is currently limited to observational and droplet studies.
  • In highly populated areas that have high infection rates—eg, USA or South Africa—the use of masks will probably outweigh any potential downsides.
  • If larger relative effects of masks are confirmed by forthcoming trials, and the entire population wants to make a contribution to reduce transmission, then a few months of universal facemask wearing would achieve a lot, but it will come at a cost. That cost might be lower than not reopening businesses and schools once baseline risk achieves acceptable levels.
  • No intervention is associated with affording complete protection from infection, so a combination of measures will always be required, now and during the next pandemic.

Actions and issues from this study for local consideration?

  • Acknowledgment of current uncertainty about the quality of evidence and understanding the difference between relative and absolute reductions in risk is key to sort out the many questions and the confusion about facemasks. Those developing recommendations and policy makers can make choices about the type of facemask, influenced by baseline risk, cost, equity, acceptability, and feasibility, but they should be transparent about the context and criteria they consider in their recommendations.
  • Public health measures to implement facemask use will be more crucial in settings with higher baseline risk for transmission.
  • WHO advises several populations to wear facemasks, including people with symptoms and vulnerable populations. Even if additional studies show that facemasks have small relative effects or no effect when used broadly, framing the precautionary principles when baseline risk is high might suggest that facemasks use in community settings with reduced physical distancing might be justified.
  • Even if some people do not have access to a facemask, those who do might prevent the spread of infection to disadvantaged populations.
  • From a public health perspective, it is important to emphasise the importance of other risk mitigation strategies, aimed at reducing the number, proximity, and duration of interpersonal contacts, respiratory and hand hygiene measures, and engineering measures in built environments. Facemask use should not substitute for these risk mitigation strategies, but might offer benefit. For example, in high baseline risk settings where it might be difficult to maintain physical distancing, such as work and school environments.

Recommended action for: Public Health



SARS-CoV-2, SARS-CoV-1 and MERS-CoV viral load dynamics, duration of viral shedding 1 and infectiousness-a living systematic review and meta-analysis

  • M. Cevik, M. Tate, O. Lloyd, A. Enrico Maraolo
  • medRxiv, 29th July 2020- PREPRINT, not yet peer reviewed.
  • Quality of Evidence:  Moderate                          
  • Strength of Recommendation: Strong

What was the study about?

  • Systematic review and meta-analysis on viral load kinetics and the duration of viral shedding as an important determinant for disease transmission.
  • Objective: To characterise viral load dynamics, duration of viral RNA and viable virus shedding of SARS-CoV-2 in various body fluids and to compare SARS-CoV-2 viral dynamics with SARS-CoV-1 and MERS-CoV.
  • Location: not specified

What were the key findings?

  • Viral shedding occurs when a virus replicates inside an individual and is released into the environment.
  • The study found the mean SARS-CoV-2 RNA shedding duration in the upper respiratory tract, lower respiratory tract, stool and serum were 17.0, 14.6, 17.2 and 16.6 days respectively.
  • Mean duration of SARS-CoV-2 RNA shedding was positively associated with age (p=0.002), but not gender (p = 0.277).
  • SARS-CoV-2 viral load in the upper respiratory tract appears to peak in the first week of illness, while SARS-CoV-1 and MERS-CoV peak later.
  • No live virus was isolated from the culture beyond day nine of symptoms despite persistently high viral RNA loads, thus emphasising that the infectious period cannot be inferred from the duration of viral RNA detection.
  • High SARS-CoV-2 titers are detectable in the first week of illness with an early peak observed at symptom onset to day 5 of illness.
  • This finding is supported by several studies demonstrating a relationship between viral load and viability of virus, with no successful culture from samples below a certain viral load threshold
  • The findings suggest similar transmission potential among both groups at the onset of infection, but a shorter period of infectiousness in asymptomatic patients. This is in keeping with viral kinetics observed with other respiratory viruses such as influenza and MERS-CoV. However, given potential delays in the isolation of patients, effective containment of SARS-CoV-2 may be challenging even with an early detection and isolation strategy.

Actions and issues from this study for local consideration?

  • This review underscores the importance of early case finding and compliance with the updated Government guidance of 10 days isolation, as well as public education on the spectrum of illness.

Recommended action for: Public Health, Communication Team


Assessment of Community-Level Disparities in Coronavirus Disease 2019 (COVID-19) Infections and Deaths in Large US Metropolitan Areas

  • S. Adhikari, N.P Pantaleo, J.M., Feldman O. Ogedegbe, L. Thorpe
  • JAMA Network open
  • July 28th 2020
  • Quality of Evidence:  Moderate                                       
  • Strength of Recommendation: Strong

What was the study about?

  • Cross-sectional study examining the association of neighbourhood race/ethnicity and poverty with COVID-19 infections and related deaths in urban US counties, hypothesising disproportionate burdens in counties with a larger percentage of the population belonging to minority racial/ethnic groups and a higher rate of poverty.
  • Objective: To assess the association of neighbourhood race/ethnicity and poverty with COVID-19 infections in US counties.
  • Location: USA

What were the key findings?

  • In more-poverty counties, those with substantially non-White populations had an infection rate nearly 8 times that of counties with substantially White populations (RR, 7.8; 95% CI, 5.1-12.0)
  • In more-poverty counties, those with substantially non-White populations had a death rate more than 9 times greater than that of counties with substantially White populations (RR, 9.3; 95% CI, 4.7-18.4).
  • Among both more-poverty and less-poverty counties, those with substantially non-White or more diverse populations had higher expected cumulative COVID-19 incident infections compared with counties with substantially White or less-diverse populations (e.g., more diverse counties with less poverty: RR, 3.2; 95% CI, 2.3-4.6).
  • While the excess burden of both infections and deaths was experienced by poorer and more diverse areas, racial and ethnic disparities in COVID-19 infections and deaths existed beyond those explained by differences in income.

Actions and issues from this study for local consideration?

  • Research and access to community information with individual-level health data is likely to provide additional insights on racial and ethnic disparities in COVID-19 infections and deaths

Recommended action for: Public Health, Local Engagement Board


Estimation of Viral Aerosol Emissions From Simulated Individuals With Asymptomatic to Moderate Coronavirus Disease 2019

  • M. Riediker, D-H. Tsai 
  • JAMA
  • 27th July 2020
  • Quality of Evidence:  Moderate                                         
  • Strength of Recommendation: Weak

What was the study about? 

  • A mathematical modelling study where breathing and coughing by a simulated individual with COVID-19 were estimated to release large numbers of viruses in a poorly ventilated room with a coughing person.
  • Objective: To estimate the virus levels released from individuals with asymptomatic to moderate COVID-19 into different aerosol sizes by normal breathing and coughing, and to determine what exposure could result from this in a room shared with such individuals.
  • Location: USA

What were the key findings?

  • In this modelling study, breathing and coughing were estimated to release large numbers of viruses ranging from thousands to millions of virus copies per cubic meter in a room with an individual with COVID-19 with a high viral load, depending on ventilation and microdroplet formation process.
  • The estimated infectious risk posed by a person with typical viral load who breathes normally was low. 
  • The results suggest that the viral load in the air can reach critical concentrations in small and poorly ventilated rooms, especially when the individual is a super-spreader, defined as a person emitting large number of microdroplets containing a high viral load.
  • However, people who are high emitters are not very common in the population and our findings suggest that only few people with very high viral load pose an infection risk in poorly ventilated closed environments

Actions and issues from this study for local consideration?

  • Respiratory protection is recommended whenever there is a chance to be in the same room with an individual, whether symptomatic or not, particularly if they are coughing and especially when one is in the room for a prolonged period.

Recommended action for: Public Health, Communication team colleagues, Suffolk Covid19 Health Protection Board

Effect of COVID-19 lockdown on alcohol consumption in patients with pre-existing alcohol use disorder

  • J. U. Kim et al.
  • Lancet Gastroenterology & Hepatology
  • 4th August 2020.
  • Quality of Evidence: Low                              
  • Strength of Recommendation: Strong

What was the study about?

  • Telephone survey of patients with pre-existing alcohol disorders at the alcohol clinic of St Mary's Hospital, London.
  • Objective:  To assess the impact of lockdown on alcohol consumption.
  • Location: London

What were the key findings?

  • Lockdown represents a risk factor for increasing alcohol consumption in people with alcohol use disorders and relapse for those who were previously abstinent.
  • Lockdown causes different behavioural changes on alcohol intake, with about 20% of individuals increasing or decreasing their normal alcohol consumption. Although psychosocial distress has been well recognised as a risk of relapse and increased alcohol consumption, the reduction might be associated with decreased financial ability and the decreased availability of on-site alcohol areas (eg, pubs or bars).
  • There were no distinct protective factors for relapse, suggesting that pre-lockdown abstinence status is not protective against lockdown-related relapse. The mean duration of abstinence before relapse was long, which has been previously identified as a strong predictor of continuous abstinence. Lockdown might overshadow this paradigm.
  • Those who relapsed had a clinically significant average level of alcohol consumption of nearly 49 units weekly post-relapse, which is concordant with previous studies of a high risk of harmful drinking after relapse.
  • In a subgroup of patients who had clinical contact during lockdown, contact with an alcohol nurse specialist was a positive predictor for reducing relapse and improving new abstinence.

Actions and issues from this study for local consideration?

  • Those who do relapse are at a high risk of harmful drinking and require a tailored approach for follow-up and intervention.
  • Support from alcohol liaison services could prevent relapse during lockdown.

Recommended action for: Public Health, Substance misuse service providers

National Institute of Care Excellence (NICE) Guidelines COVID-19 guidance

NICE Implementation and Core Local Authority GuidancE Review Group (NICER Suffolk) is a group led by Public Health Suffolk, which facilitates review and implementation of NICE guidance across Suffolk County Council. The group has temporarily suspended general NICER meetings and have replaced this in the interim with COVID-19 only NICER meetings to ensure implementation of new guidance by NICE on COVID-19 relevant to Suffolk County Council.  Relevant guidelines are reviewed by the group and members from relevant Directorates will be taking these back to their colleagues to scope and incorporate into the ongoing COVID-19 work. 

Newly released NICE guidelines this week that are relevant to Suffolk system are listed below

No new guidance this week.



COVID-19 casts light on respiratory health inequalities

  • [No author]
  • Lancet Respiratory Medicine
  • August 2020 (not dated).
  • Quality of Evidence:  Very low                    
  • Strength of Recommendation: Strong
  • What was the study about?

  • Editorial to raise awareness of the impact of respiratory health inequalities and call for action.
  • Objective: Call for action to address respiratory health inequalities.
  • Location: Not specified

What were the key findings?

  • COVID-19 has disproportionately affected people from disadvantaged populations and marginalised communities.
  • These imbalances will magnify the already pervasive inequalities associated with respiratory health across the lifespan, and the full effects might be apparent only in the decades to come.
  • People living in social deprivation and those from BAME communities have disproportionately greater exposure to the major risk factors for respiratory diseases—tobacco smoke, air pollution, obesity, infections, and hazardous occupations—and a higher prevalence of several conditions, including COPD, asthma, lung cancer, and sleep apnoea.
  • Inequalities are especially pronounced in children with respiratory disorders such as asthma and are evident in cystic fibrosis: children from disadvantaged backgrounds have worse growth and lung function than those from more affluent backgrounds.
  • The diversion of health care during the pandemic from cancer screening and treatment, paediatric and adult respiratory services for chronic conditions, and vaccination programmes will all affect long-term respiratory health.

Actions and issues from this study for local consideration?

  • We must make a concerted effort to improve understanding of the multitude of factors that underpin these inequities and their complex interactions with respiratory health.
  • Improved education and understanding among health-care professionals of inequalities and campaigns to enhance awareness and health-care access for patients are paramount to reducing health disadvantages.
  • The overarching social inequalities that underpin the imbalance in risk factors and determinants of respiratory health need to be targeted through carefully considered, long-sighted health and social policies.
  • Strategies to reduce poverty by supporting people to secure appropriate employment, improve provision of income support, reduce the educational attainment gap, and promote better nutrition, in addition to increased provision of affordable housing and reduced overcrowding, are sorely needed.
  • Measures to strengthen smoking cessation programmes, reduce air pollution, and improve conditions for those working in hazardous occupations are essential to tackle some of the key risk factors.
  • Respiratory health inequalities related to and exacerbated by COVID-19 must be viewed in light of social deprivation and discrimination.
  • Public health goals and policies that promote social, economic, and health equity must be at the heart of pandemic recovery plans to eliminate these deep-rooted inequalities in respiratory health across the lifespan.

Recommended action for: Public Health, local government policy makers, housing, smoking cessation services

Finding a path to reopen schools during the COVID-19 pandemic

  • W. J. Edmunds
  • Lancet Child & Adolescent Health
  • 3 August 2020


What was the study about?

  • Comment on how to reopen schools
  • Objective: Summarise articles on transmission of SARS-CoV-2 in educational settings.
  • Location: Australia and UK

What were the key findings?

  • School closures are likely to result in damage to children's social, psychological, and educational development, as well as lost income and productivity in adults who cannot work because of childcare responsibilities.
  • It is likely that children from low-income backgrounds will probably be more adversely affected than children from high-income backgrounds.
  • Compared with influenza and most other respiratory infections, children seem to be largely spared COVID-19. If infected, children typically have mild disease.
  • An Australian study studies suggests very low rates of infection, however it needs to be interpreted with caution, because mitigation measures were in place: most educational facilities were closed briefly after case identification, and close contacts were expected to home quarantine for 14 days. A similar study from Ireland, also done during the early part of the epidemic, in which six confirmed cases (three adults and three children) attended schools found no secondary cases were documented as arising from the paediatric cases.
  • An outbreak centred in a high school in northern France had high infection attack rates in students (aged 14–18 years) and staff (38% and 49%, respectively), and much lower among parents and siblings (11% and 10%, respectively) suggesting that infection was concentrated within the school environment. A follow-up study in local primary schools revealed much lower infection rates (6–12%) among staff, students and family members, and no convincing evidence of any secondary transmission within schools. The contrast between the infection rates in the secondary and primary schools might turn out to be important.
  • Reopening schools (even partially) and the accompanying return to more normal contacts is likely to lead to a second wave of infections, unless testing is scaled up significantly. Unfortunately, it is not clear from their analysis whether the increase in cases that occurs when schools are reopened in the model is due to increased contact between children or increased contact between adults who can now return to work and leisure activities.
  • Many questions remain, including whether there are age-related differences in susceptibility and the likelihood of transmission between children and adolescents.

Actions and issues from this study for local consideration?

  • Macartney and colleagues suggest that educational settings can remain open provided measures, such as contact tracing, quarantine, and even school closures, are in place to limit spread when cases occur.
  • Panovska-Griffiths and colleagues suggest that the safe reopening of schools in the UK could occur if the TTI (Test-Trace-Isolate) programme is greatly improved.

Recommended action for: Public Health, Children’s and Young People’s Services


Quality of Evidence:  Low                                             

Strength of Recommendation: Strong

What was the study about?

  • Comment piece (McCauley) on prospective, observational cohort study (Nguyen) in the UK and the USA of the general community, including front-line health-care workers, using self-reported data from the COVID Symptom Study smartphone application (app) from March 24 (UK) and March 29 (USA) to April 23, 2020. Also, an observational cohort study of health-care workers in the Capital Region of Denmark, including students and compared with blood donors in the same region in the study period.
  • Objective: To assess COVID-19 infection in front-line health-care workers (through prevalence of antibodies and previous symptoms) compared with the general community and the effect of personal protective equipment (PPE) on risk.
  • Location: UK & USA, Denmark

What were the key findings?

  • In the UK and the USA, risk of reporting a positive test for COVID-19 was increased among front-line health-care workers.
  • Secondary and post-hoc analyses suggested adequacy of PPE, clinical setting, and ethnic background were important factors.
  • In Denmark, the prevalence of health-care workers with antibodies against SARS-CoV-2 was low but higher than in blood donors.
  • In Denmark, frontline health-care workers working in hospitals had a significantly higher seroprevalence than health-care workers in other settings. Health-care workers working on dedicated COVID-19 wards had a significantly higher seroprevalence than other frontline health-care workers working in hospitals. 53·5% of seropositive participants reported symptoms attributable to SARS-CoV-2. Loss of taste or smell was the symptom that was most strongly associated with seropositivity.

Actions and issues from this study for local consideration?

  • Health-care systems should ensure adequate availability of PPE and develop additional strategies to protect health-care workers from COVID-19, particularly those from minoritised ethnic backgrounds.
  • Mandated universal masking would help to both protect health-care workers (since studies have shown a reduction in COVID-19 cases among health-care workers after implementation of universal masking) and target the underlying reason for the myriad public health and economic challenges that countries are navigating.
  • Leaders should assume responsibility for front-line health-care workers' safety. Governments need to cooperate with other nations to ensure equitable distribution of PPE.

Recommended action for: Public Health, Those employing health care workers