"As an exception during this period of health crisis, some of the publications mentioned are at the time of writing still in pre-publication, undergoing peer review and subject to change. The results of this pre-print study should be interpreted with utmost caution."
Care home workers followed by health care workers were most likely to test positive for COVID-19 in a four-week period during 'lockdown', compared with the general population.
The findings from the REal-time Assessment of Community Transmission (REACT 1) programme, a nationally representative prevalence survey of SARS-CoV-2 virus swab-positivity in the community in England, have been posted on the pre-print platform medRxiv and are undergoing peer review.
Researchers found 159 positives from 120,610 swabs, giving an average prevalence of 0.13 per cent (95% CI, 0.11%-0.15%) from 1 May 2020 to 1 June 2020.
Compared with non-key workers, odds of swab-positivity were 7.7 (95% CI, 2.4-25) among care home (long-term care facilities) workers and 5.2 (95% CI, 2.9-9.3) among health care workers. However, some of the excess risk associated with key worker status was explained by recent contact with COVID-19 cases. Recent contact with a known COVID-19 case was associated with odds of 24 (95% CI, 16-38) for swab-positivity.
Results showed a decreasing prevalence with a halving time of 8.6 (95% CI, 6.2-13.6) days, implying an overall reproduction number of 0.57 (95% CI, 0.45-0.72).
Adults aged 18-24 years had the highest swab-positivity rates, whereas those >64 years had the lowest.
Of the 126 participants who tested positive with known symptom status in the week prior to their swab, 39 reported symptoms, whereas 87 did not, giving an estimate that 69 per cent (95% CI, 61%-76%) of people were symptom-free for the seven days prior testing positive in this community sample.
Those of Asian ethnicity were more likely to test positive than those of white ethnicity. The researchers, therefore, suggest that higher infection rates could have contributed towards the higher death rates observed in this ethnic group.
