Covid-19 is the novel coronavirus responsible for the ongoing global outbreak of acute respiratory disease and viral pneumonia. Covid-19 is classified in the UK as a high consequence infectious disease (HCID); an acute infectious disease, with typically a high case-fatality rate, and for which there may not be effective prophylaxis or treatment. 

Currently the UK strategy is aimed at containment. Key to this is screening and respiratory isolation of any person who might be at risk of transmitting Covid-19. Screening for a high consequence infectious disease in the UK is predominantly occurring in secondary care where staff are trained in wearing and removing personal protective equipment (PPE). While the UK has had few confirmed cases of Covid-19, London’s position as an international transport hub with a diverse international population, as well as the broad “catch all” case definition needed for containment has challenged secondary care services in London to screen and safely isolate a large number of people under investigation for Covid-19. 

Our initial experience across London is that the majority of those referred for testing have mild symptoms without severe disease. These are patients that do not require an emergency ambulance or review in secondary care facilities which were already under record strain prior to this outbreak. They are able to safely isolate themselves at home, however transport to and from secondary care in order to be tested is challenging. People under investigation should not use public transport systems including the London Underground network which facilitates transmission of respiratory viruses. [1] UK and European guidelines mandate the use of ambulances to transport people under investigation for a high consequence infectious disease. [2] Therefore, the person under investigation requires an ambulance to transport them to and from an acute trust which then must be taken out of service and decontaminated between patients. This takes up to eight hours and places a huge burden on already stretched London ambulance services.

To address these challenges to the ambulance service and secondary care, at the start of the current outbreak, community testing for Covid-19 was rapidly implemented across London. The community testing protocol has been developed as a collaboration across the London Ambulance service, NHS England, NHS 111, Public Health England (PHE), Healthy London Partnership and community testing partners in trusts covering much of London’s population including University College London Hospitals, St George’s University Hospital, Guys and St Thomas’ NHS Foundation trust and London North West University Healthcare trust.

Those meeting the current PHE case definition in London are referred from the NHS 111 phone service, local GP surgeries, and local emergency departments to new “community testing hubs”. Referrals to hubs are triaged by telephone to confirm that they meet the case definition, are well enough to remain at home, do not need a full healthcare professional assessment, are able to self-isolate and whose home environment is deemed appropriate for safe personal protective equipment protocols (PPE). If all those criteria are met, people under investigation are accepted for community testing. Telephone triage is well established in the NHS and self-isolation guidance follows current PHE advice.

Community testing is performed within 24 hours of referral by a healthcare professional with personal protective equipment (PPE) training. Transport to the person under investigation’s residence is currently provided by the London Ambulance Service NHS Trust who also provide a paramedic who can assist if required.  Personal protective equipment is donned outside the person under investigation’s residence, a clinical assessment is carried out, and appropriate samples collected. Patients are left with advice on self-isolation, probable dates of results, what to do in the event of clinical deterioration and an emergency contact number which in some cases is back to NHS 111. Personal protective equipment is removed outside of the property and placed in a clinical waste bag, which is then disposed of as category B waste in line with PHE guidance. This follows WHO and PHE guidance on removal of personal protective equipment when patients are isolated in rooms lacking an “anteroom” to maintain safety of testers. [3] Persons under investigation are contacted daily following community testing to check on their wellbeing until results of Covid-2019 testing are known.

In the last two weeks since the emergence of Covid-2019 and development of this pilot, London network has tested over 130 people under investigation in the community. We propose a rapid scale up of community testing in several key ways:

1. Testing more outside hospitals in the community. Thus taking pressure off stretched inpatient facilities, reducing the risk of transmission during unnecessary travel and relieving the burden on overstretched ambulance services.
2. Home-test kits to be urgently developed

To achieve scale up of this model and to release acute physicians to manage patients requiring secondary care, this week we are starting to work with district and practice nurses to provide community testing. Our experience suggests community testing is an acceptable, efficient method of screening for airborne respiratory high consequence infectious disease which is applicable across the UK. 

• See also: Coronavirus: home testing pilot launched in London to cut hospital visits and ambulance use

Ashley M Whittington, Consultant in Infectious Diseases and Acute Medicine, North West London University Hospitals NHS Trust 

Sarah Logan, Consultant in Infectious Diseases, Hospital for Tropical Diseases, University College London Hospitals Trust

Anna Goodman, Consultant in Infectious Diseases, Guy’s and St. Thomas’ NHS Foundation Trust

Angela Houston, Consultant in Infectious Diseases, St. Georges University Hospitals

Laurence John, Consultant in Infectious Diseases, North West London University Hospitals NHS Trust

Fanella Wrigley, Chief Medical Officer, London Ambulance Service NHS Trust 

Competing interests: None declared 

Written on behalf of the London Community Testing Network a collaboration between London Ambulance Service, NHS England, Public Health England, NHS 111, 111 LCW, 111 Vocare, 111 LAS, 111 Care UK, Healthy London Partnership, University College London Hospitals, St Georges University Hospital, Guys and St Thomas’ NHS Foundation Trust and London North West University Healthcare Trust

References:

1. Gosce L, Johansson A. Analysing the link between public transport use and airborne transmission: mobility and contagion in the London underground. Environ Health 2018;17(1):84. doi: 10.1186/s12940-018-0427-5 [published Online First: 2018/12/06]
2. European Centre for Disease Prevention and Control. Infection prevention and control for the care of patients with 2019-nCoV in healthcare settings. ECDC: Stockholm; 2020. https://www.ecdc.europa.eu/sites/default/files/documents/nove-coronavirus-infection-prevention-control-patients-healthcare-settings.pdf
3. WHO. Infection prevention and control during health care when novel coronavirus (nCoV) infection is suspected. 2020;https://www.who.int/publications-detail/infection-prevention-and-control-during-health-care-when-novel-coronavirus-(ncov)-infection-is-suspected