Levels of coronavirus at the height of the outbreak were three times higher than officially recorded, according to GP data – potentially moving the UK closer to herd immunity.
GPs recorded 8,985 suspected virus cases between February 14 and April 30, triple the number of people found positive for Covid-19 at test centres over the same period.
The study, led by Queen Mary University in London, also found that black, Asian and minority ethnic (BAME) adults were twice as likely to present with suspected coronavirus than white adults.
The increased risk to BAME groups was not necessarily due to other factors such as health conditions, obesity or social deprivation, the study said.
Lead author Dr Sally Hull, of Queen Mary University, said: “Our results suggest that Covid-19 prevalence during the peak of the epidemic was higher than previously thought.
“The official Covid-19 test statistics are likely to have under-represented the extent of the epidemic as many people with Covid-19 would not have been tested, including those with milder symptoms or those who could not access testing centres.”
The results of the peer-reviewed study have been published in the British Journal of General Practice.
Researchers looked at anonymised data from the primary care records of about 1.2 million adults registered with 157 practices in four east London clinical commissioning groups during the peak of the pandemic.
Three of the four boroughs studied had death rates that were in the top five for London, while 55 per cent of the population in those areas was from ethnic minorities (see graphic below showing virus deaths by ethnicity).