Infection fatality risk Is a proportion of deaths among all infected individuals.
Namely, dividing that number of deaths by the estimated number of
infected individuals, those animated here.
The infection fatality risk among 100,000 infections was obtained.
As we observed among children and the young adults it is almost
certain that the infection do not result in any deaths,
due to H1N1-2009 influenza.
However, among elderly, especially 60s who have probably the underlying co-morbidity,
it's much more common to experience the risk of death of influenca.
So findings from the seroepidemiological study can be animated for us here.
So the seroepidemiological study enable us
to infer the cumulative incidence of H1N1-2009.
And the age-dependent pattern of the infection was
seen high cumulative incidence was seen in children or
the incidents among the older adults was very low.
And that allowed to measure the proportion of death among adults
without experiencing the ascertaiment of bias.
So age-specific severity profile was estimated on a per-infection basis and
that infer what we call the infection fatality score, IFR.
However, there is a drawback.
It's difficult to assess the magnitude of an infection in real-time
during the very early stage of an epidemic.
Seroepidemiological study requires a large number of samples, and
the real-time seroepidemiological studies needs some science preparedness.
Namely the preparation of the survey in advance of the emergence
of the pandemic, which is a challenge for the next study gate.
So in summary, we have seen that ascertainment bias could
lead to overestimate the risk of death given infection.
Age-specific seroepidemiological survey has enabled us to
obtain age-specific infection profile directory.
And that has improved the estimation of the risk of death on per-infection basis.
However, the estimation was not attained in real-time.
Thank you.