This ONS study addresses some key clinical and Government priorities :
- finding out how many people across the UK have a COVID-19 infection at a given point in time, or at least test positive for it, either with or without symptoms;
- how many new cases have occurred in a given time period;
- how many people are ever likely to have had the infection.
- It will also enable estimates of the rate of transmission of the infection, often referred to as “R”.
Following completion of the pilot survey, the ONS intend the full survey to expand the size of the sample over the next 12 months and look to cover people across all four UK nations. I would suggest this survey is accelerated dramatically and that huge resources are devoted to get urgent comprehensive results at National, Regional and local level as soon as possible; ie a Trumpian warp speed ONS survey.
The preliminary results were published on 14th May. This showed the surprising results (to me anyway) that the latest estimates indicate that at any given time during the two weeks from 27 April to 10 May 2020, an average of 148,000 people (0.27% *) in England had COVID-19 within 95% confidence limits..
This estimate is based on tests performed on 10,705 people in 5,276 households.Out of the 10,705 participants’ swab tests included in this analysis, only 33 individuals in 30 households tested positive for COVID-19.
- (I make the numbers slightly different ie 33/10,705*100 = 0.31% within 30/5276*100 = 0.57% households, but that’s by the by.) Interesting that the ONS bulletin make no mention of % households and the likelihood of spead of infection between household members.)
These figures EXCLUDE people in hospital or care homes where rates of COVID-19 infection are higher. There is no evidence of differences in the proportions testing positive between the age categories 2 to 19, 20 to 49, 50 to 69 and 70 years and over. ie the numbers in each group were approximately 7-9 people (including the youngest children/teenagers group, which is extremely significant)
So, from these results,we have about one in every 400 people in England infected with covid-19 in the community, with an estimated 37,000 children/teenagers (aged 2 – 19 years), 37,000 people of working age ( 20-49 years old), 37,000 aged 50-69 years and 37,000 aged 70 years and over – very surprising results given the mortality profiles we have seen from other studies.
Covid -19 Mortality rate (0.2%) extrapolation
The figure of 0.27% is remarkably similar to the figure of 0.20% which is a estimate of the level of mortality evidenced from a number of international studies (see below).
- According to data from the best-studied countries and regions, the lethality of Covid19 is on average about 0.2%, which is in the range of a severe influenza (flu) and about twenty times lower than originally assumed by the WHO.
- Even in the global “hotspots”, the risk of death for the general population of school and working age is typically in the range of a daily car ride to work. The risk was initially overestimated because many people with only mild or no symptoms were not taken into account.
- Up to 80% of all test-positive persons remain symptom-free. Even among 70-79 year olds, about 60% remain symptom-free. Over 95% of all persons show mild symptoms at most.
- Up to one third of all persons may already have a certain background immunity to Covid19 due to contact with previous coronaviruses (i.e. common cold viruses).
If 0.2% is the percentage of the number of deaths in the UK, based on the cumulative death toll to date (16th May) of 34,466, then the number of people who have had covid-19 or have a background immunity already equates to 17,233,000 million people ie 25% of the population.
This massive discrepancy in the ONS survey results of 148,000 people in the community infected with covid-19, and possibly 17.2 million people have had or are immune to covid 19, highlights the importance of the antibody test recently approved by Public Health England.
Made by the pharmaceutical company Roche, this may now be used to determine how many of the UK population has been infected by Covid-19.
Antibody testing could be hugely useful as the country emerges from lockdown as the presence of antibodies to the virus in a person’s blood proves they have had it. However, whether the person is immune and if so, how long that immunity lasts, are still open questions.
The test is likely to be used to find out whether particular areas of the country, or people in certain professions, have had Covid-19, but it will not give individuals an immunity passport to let them restart their social lives.