Re: Is it possible to implement the proposals in the Editorial "Covid-19: why is the UK government ignoring WHO’s advice? (1)"
In a fast expanding epidemic, once the surge is controlled by universal mass physical distancing, control of contacts of new cases is the public health option of choice (2). This has worked in the past and has been shown to be successful with COVID-19 in China in combination with physical distancing and without the need for physical distancing in South Korea, Singapore and Hong Kong (3). There they manage to control their epidemics without recourse to population lockdown. This is due to planning for major epidemics with serious intent following their SARS experience. The planning allowed the rapid deployment of public health staff to trace contacts and virus test in sufficient numbers required to confirm new cases through the contact tracing approach. The results are impressive. The economies and schools continue nearly as before.
The UK situation
The lockdown will start to reduce new cases immediately and deaths three weeks later. There is talk and models depicting the effect of pulsed reduction of physical distancing (4). This will not control the epidemic but simply reduce the cases requiring hospital care. There is also talk about testing and smart phone applications. These technologies support but do not obviate or supplant the fundamental need for finding and quarantining cases and contacts. The epidemic is at different stages in different places in the UK. The need to maintain physical distancing and thereby curtail economic activity will be different in different parts of the country.
Decentralisation is crucial
Control of communicable disease was until the re-organisation in 2002 held at district level with a Director of Public Health looking after each local health authority. This allowed local knowledge of the community, the local politicians and leaders, the laboratory, the hospital and its consultants and the GPs. Control is not possible without this local expertise (1). There is a Director of Public Health in each local authority who together with support from a Consultant in Health Protection/Communicable Disease Control and the local Health Protection Team from Public Health England can take the management responsibilities for each local authority.
The control of COVID-19 should be managed by the local authority who should have the responsibility to start and modify physical distancing measures within their boundaries. The legal powers are already available through Schedule 21 (Powers relating to potentially infectious persons) of the Coronavirus Act 2020. Public Health England which has a strong central and regional structure can co-ordinate in England. Public health functions are already devolved in Scotland, Wales and Northern Ireland but may benefit from further decentralisation. China demonstrates the success of this hierarchical approach (5).
Case finding and contact tracing
Case finding and contact tracing remain the key control measure and should be re-started immediately in each local authority (2). The following tables show the staff required to handle new cases and control spread through contact tracing and quarantine (6). The numbers required now and two weeks later assuming decay in numbers started on 6th April (as will have occurred in some but not all areas) are shown in Table 3. Once established the generalised physical distancing measures can be relaxed and the local economy return to normal. These measures can be titrated if surging of cases occurs. The assumptions used to estimate the staff required are in Table 1 and the hours of staff required are in Table 2.
Local public health capacity
Each new case will require 102 hours of community health staff and volunteers time to trace 90 contacts and test 6.3 symptomatic contacts a third of whom will have COVID-19. The requirement for staff will vary with time as physical distancing is currently reducing contact numbers and should become less if phone applications as used in Singapore are used by individuals here. On average there will need to be 2.8 full time local staff and trained volunteers to cope with each new case.
A selection of health visitor (HV) and environmental health officer (EHO) staff can be relieved of current duties and deployed to lead local teams of volunteers to contact trace (13). Most local authorities have established volunteer registers (14) and recently retired HVs and EHOs can join the volunteers. The system of contact tracing should be up and running in 5 working days. It should be possible for most Directors of Public Health alongside the Public Health Physician secondee from Public Health England to assess if they have control of the spread of the virus in their district a week later.
Initially the number of cases can be best estimated from local deaths. As the system gets under way new cases will be notified in the standard way for which testing is helpful but not necessary. The number of cases will fall as physical distancing succeeds as in China. Probably 3000 volunteers will be needed by late April in the averaged sized local authority. Training will take one day as will setting up the administrative arrangements using local authority resources. Testing facilities can be negotiated with the local health laboratory. The local authority will take on the public information function.
Exiting physical distancing
Once under control locally the local authority can relax physical distancing measures to get schools reopened and the local economy back on its feet. Most local authorities outside the cities will be in sufficient control to do this by the end of April if and when cases are rapidly identified and their contacts rapidly traced. Cities will inevitably take longer to control but this is all the more of a reason to start case finding and contact tracing now. Tighter physical distancing measures and travel restrictions from hot areas may be required if the epidemic gets out of control again. The public can be made aware of this possibility by their local leaders.
In conclusion an early return to full economic activity is possible in many parts of the country if local authorities are given the devolved powers to control physical distancing, if the viral tests are made available for contact tracing and if local public health departments take back communicable disease control (15).
1. Pollock AM, Roderick P, Cheng KK, Pankhania B. Covid-19: why is the UK government ignoring WHO’s advice? BMJ [Internet]. 2020 Mar 30 [cited 2020 Apr 6];368. Available from: https://www.bmj.com/content/368/bmj.m1284
2. Contact tracing: Public health management of persons, including healthcare workers, having had contact with COVID-19 cases in the European Union – first update [Internet]. European Centre for Disease Prevention and Control. 2020 [cited 2020 Apr 5]. Available from: https://www.ecdc.europa.eu/en/publications-data/contact-tracing-public-h...
3. Ng Y, Li Z, Chua YX, Chaw WL, Zhao Z, Er B, et al. Evaluation of the Effectiveness of Surveillance and Containment Measures for the First 100 Patients with COVID-19 in Singapore — January 2–February 29, 2020. MMWR Morb Mortal Wkly Rep. 2020 Mar 20;69(11):307–11.
4. Report 11 - Evidence of initial success for China exiting COVID-19 social distancing policy after achieving containment [Internet]. Imperial College London. [cited 2020 Apr 6]. Available from: http://www.imperial.ac.uk/medicine/departments/school-public-health/infe...
5. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) [Internet]. [cited 2020 Apr 7]. Available from: https://www.who.int/publications-detail/report-of-the-who-china-joint-mi...(covid-19)
6. Resource estimation for contact tracing, quarantine and monitoring activities for COVID-19 cases in the EU/EEA [Internet]. European Centre for Disease Prevention and Control. 2020 [cited 2020 Apr 5]. Available from: https://www.ecdc.europa.eu/en/publications-data/resource-estimation-cont...
7. Estimates of the population for the UK, England and Wales, Scotland and Northern Ireland - Office for National Statistics [Internet]. [cited 2020 Apr 11]. Available from: https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigrati...
8. Keeling MJ, Hollingsworth TD, Read JM. The Efficacy of Contact Tracing for the Containment of the 2019 Novel Coronavirus (COVID-19). medRxiv. 2020 Feb 17;2020.02.14.20023036.
9. Global Health Data Exchange | GHDx [Internet]. [cited 2020 Apr 8]. Available from: http://ghdx.healthdata.org/
10. Rapid risk assessment: Coronavirus disease 2019 (COVID-19) pandemic: increased transmission in the EU/EEA and the UK – eighth update [Internet]. European Centre for Disease Prevention and Control. 2020 [cited 2020 Apr 9]. Available from: https://www.ecdc.europa.eu/en/publications-data/rapid-risk-assessment-co...
11. Jombart T, Zandvoort K van, Russell T, Jarvis C, Gimma A, Abbott S, et al. Inferring the number of COVID-19 cases from recently reported deaths. medRxiv. 2020 Mar 13;2020.03.10.20033761.
12. Leung K, Wu JT, Liu D, Leung GM. First-wave COVID-19 transmissibility and severity in China outside Hubei after control measures, and second-wave scenario planning: a modelling impact assessment. The Lancet [Internet]. 2020 Apr 8 [cited 2020 Apr 9];0(0). Available from: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30746-7/abstract
13. Public Health England. Best start to life and beyond; improving public health outcomes for children, young people and families [Internet]. 2018. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploa...
14. Community advice [Internet]. Coronavirus advice in Devon. [cited 2020 Apr 8]. Available from: https://www.devon.gov.uk/coronavirus-advice-in-devon/document/community/
15. Pollock AM. Covid-19: local implementation of tracing and testing programmes could enable some schools to reopen. BMJ [Internet]. 2020 Mar 24 [cited 2020 Apr 6];368. Available from: https://www.bmj.com/content/368/bmj.m1187
Table 1 – Assumptions used to calculate staff requirements for contact tracing
Each new case has 36 high risk traceable contacts (6)
Each new case has 54 low risk contacts (6)
Population UK – 66,435,550
Average Local Authority population 357180
URTI prevalence 42/1000 pop (7)
Reproductive number Ro 2.5 (10)
2 Car hours to test station or home and back
Case fatality rate 0.66% (11)
Decay per day from peak 5.5% (12)
Estimates of hours required (6)
Table 2 – Staff required to contract trace one new case
Interview new case 2 hours
Register case 0.25 hours
Create contact list 4 hours
Classify contacts 1 hour
Interview contacts 65 hours
Monitor high risk contacts 10.8 hours
Monitor low-risk contacts 1.6 hours
Test symptomatic contacts 6.3 hours
Car service all symptomatic contacts 12.6 hours
Total 101.6 hours = 2.8 WTE (36 hours/wk)
Table 3 – Illustrative example of staff required now and in two weeks after peak for UK and the average Local Authority in the UK
Location UK Average Local Authority
Population 66,435,550 357,180
Average weekly caseload 6th April 485,195 4,242
WTE required 6th April 1,369,516 11,975
Weekly caseload 2 weeks after peak 188,834 1,123
WTE required 2 weeks after peak 533,005 3,169
Competing interests: No competing interests