Timely research from Newcastle Hospitals and University has shown that the rate of infection among NHS staff treating patients is no higher than for those in non-clinical roles.  These findings, published as a piece of correspondence in The Lancet, may offer some reassurance to NHS staff on the front line.

The work has been carried out by researchers and medics at the Newcastle Upon Tyne Hospitals NHS Foundation Trust and Newcastle University – the key findings are

Delivering staff testing during the pandemic is feasible.

The rates of positive tests in patient-facing staff were no higher than in those staff in clerical or administrative roles who have no patient contact.

The data provides a unique insight into the COVID-19 epidemic in England. The growth in cases clearly “flattened” after the introduction of social distancing measures.

Testing

The research demonstrates how testing of NHS staff at volume is possible during a pandemic, with the development of an efficient model which returns results to staff within 48 hours of their initial contact.

From 10th to 31st March, the Trust tested 1,654 staff and in the subsequent two weeks not covered in this report, they have doubled this number. They tested mainly hospital employees from two hospitals in Newcastle, but also local GPs in Newcastle and employees of the North East Ambulance Service.

Staff contact Occupational Health by email and after an initial symptom screen, those with possible symptoms (new continuous cough and/or fever) are given an appointment within 24 hours for the standard PCR test (RdRP assay developed by Public Health England) in a designated screening pod, staffed by trained nurses. They are provided with written advice about self-isolation and receive an email with their test result within the next 24 hours.

Rate of positive tests

Data on the roles of 1,029 of the staff tested was used to identify three groups – those that were directly patient-facing e.g. nurses, doctors, allied health professionals, porters; non-patient facing but potentially at higher risk of an infection caught in a hospital e.g. domestic and laboratory staff; and finally, non-clinical staff e.g. clerical, administrative, information technology, secretarial etc.

Comparison of the rates of those who tested positive showed no evidence of a significant difference between the three groups. This suggests that transmission of SARS-CoV-2 from patients to NHS staff may reflect wider patterns of SARS-CoV-2 transmission in the community – and is consistent with observations in China, where staff testing was widespread.

The researchers found rates of infection of 15.4% among directly patient facing staff; 16.3% among those non-patients facing, but in roles with a potentially higher risk; and 18.4% among non-clinical staff.

Given that non-clinical staff had similar positivity rates to ‘frontline’ staff, the researchers conclude that current isolation protocols and personal protective equipment appear sufficient to prevent hospital transmission.

The team admits limitations to the data as they were unable to identify roles among all the staff tested. The small number of non-clinical staff tested also meant that it was not possible to meaningfully compare transmission dynamics between these groups, where more complex patterns may exist, but studies are ongoing.

Flattening following social distancing 

Initially, rates of positive tests for Covid-19 were relatively low, at 5% on 10/11th March, but rose steadily throughout the testing period, to 20% on 30/31st March. There was a period of exponential growth from 10th March until around the 24th March with a doubling time of 2.2 days.

However, from around the 24th March onward, when the UK Government introduced further social distancing measures, the rate of increase appeared linear.

Although it is not possible to assign causality, it seems plausible that these measures have reduced community transmission of SARS-CoV-2 in the Newcastle region.

Dr Duncan is part of Newcastle Health Innovation Partners (NHIP), a recently designated National Institute for Health Research – NHS England / Improvement Academic Health Science Centre bringing the region’s world-class research, NHS and city partners together.