The early spread of COVID-19 could have been prevented if initial case definitions had been less stringent and extensive community testing had been in place sooner, according to new research from the University of Nottingham.
In the new study, experts from the University's School of Life Sciences retrospectively tested routine respiratory samples taken from patients at a Nottingham teaching hospital dating back to early January 2020.
The results provide evidence that COVID-19 was already circulating widely in local communities in the UK in early February and into March, and was undetected because of restrictive case definitions that informed testing policy at the time.
Initial testing for COVID-19 in the UK required a strict criteria to be met, specifically a recent travel history to Hubei province or contact with a known case and one or more of fever, shortness of breath or new and persistent dry cough. This criteria was revised on several occasions to include travel to mainland China and several other Asian countries initially, then expanded further to include Iran and northern Italy, before finally being removed as essential criteria for diagnostic testing by mid-March.
To better understand the prevalence and emergence of COVID-19 in the UK before the broadening of case definition criteria and wider testing, the team of experts conducted a retrospective screening of case histories to identify individuals with symptoms compatible with COVID-19, as well as retrospective testing of archived diagnostic specimens submitted for respiratory virus screening.
Their results showed that the virus was already circulating in community and resulted in several hospital admissions and deaths. The earliest positive sample was obtained on 21 February from a woman who was admitted to hospital with severe breathing difficulties, who sadly later died. Therefore, not only was she the first UK case of community-acquired coronavirus infection, she was also the first UK death.
DNA sequencing showed that there had been multiple introductions of the virus into the region before widescale testing was introduced, and it also showed that the first official case of coronavirus in the area – a traveller who had returned from South Korea who tested positive on the 28 February, had most likely caught the virus in Nottingham rather than in Korea, as had been assumed.
Intensive sequencing of virus strains circulating through March, when there was very limited community testing, showed numerous introductions of different strains of the virus, which went undetected.
Professor Jonathan Ball, one of authors of the study, said: "Our data highlights the importance of timely and extensive community testing to prevent future widespread transmission of the virus. Had the diagnostic criteria for COVID-19 been widened earlier to include patients with compatible symptoms but no travel history, it is likely that earlier imported infections would have been detected, which could have led to an earlier lockdown and lower deaths. However, the capacity for testing available nationally was not sufficient at the time to process the volume of testing required with a broader case definition.
"In order to prepare for any future pandemic such as this, the UK urgently needs to invest in and expand diagnostic capacity within NHS and PHE diagnostic laboratory services. Any lasting investment in the human resources and associated infrastructure to achieve a more agile epidemic response both nationally and globally will undoubtedly save lives and drastically reduce the adverse impact of such outbreaks on the economy."
A full copy of the report can be found here.
