Alternative approaches
An alternative approach for estimating the spread of the COVID-19 virus
undertaken by Dimdore-Miles and Miles (5) used predictive mathematical
modeling for the UK and other countries and applied this to daily new
cases of the virus. As did our projection, they favoured high values for
the number of people infected but asymptomatic, with a multiplier of
approximately 200 on the diagnosed cases of COVID-19 in late April 2020,
to derive a total population estimate of infection (5). The authors,
acknowledged that the result is very sensitive to whether the
transmission rate of the virus is different for symptomatic and
asymptomatic cases, something about which there is significant
uncertainty. The differences between the estimates given by different
models, illustrate how difficult it is to estimate the spread of the
COVID-19 virus until very large samples of the population can be tested,
as is now happening in the UK.
Nevertheless the fact that the Office of National Statistics (ONS)
weekly results (6) suggest that around 80% of people testing positive
for COVID-19 have no symptoms suggests that COVID-19 infections in many
cases have a minimal impact on health, as severe / life threatening as
the infection may be in others.