A rapid risk analysis tool to prioritise response to infectious disease outbreaks

Epidemics are influenced by both disease and societal factors
and can grow exponentially over short time periods. Epidemic
risk analysis can help in rapidly predicting potentially serious
outcomes and flagging the need for rapid response. We
developed a multifactorial risk analysis tool ‘EpiRisk’ to
provide rapid insight into the potential severity of emerging
epidemics by combining disease-related parameters and
country-related risk parameters. An initial set of 18 disease
and country-related risk parameters was reduced to 14
following qualitative discussions and the removal of highly
correlated parameters by a correlation and clustering
analysis. Of the remaining parameters, three risk levels
were assigned ranging from low (1) moderate (2) and high
(3). The total risk score for an outbreak of a given disease
in a particular country is calculated by summing these 14
risk scores, and this sum is subsequently classified into
one of four risk categories: low risk (<21), moderate risk
(21–29), high risk (30–37) and extreme risk (>37). Total
risk scores were calculated for nine retrospective outbreaks
demonstrating an association with the actual impact of
those outbreaks. We also evaluated to what extent the risk
scores correlate with the number of cases and deaths in 61
additional outbreaks between 2002 and 2018, demonstrating
positive associations with outbreak severity as measured by
the number of deaths. Using EpiRisk, timely intervention can
be implemented by predicting the risk of emerging outbreaks
in real time, which may help government and public health
professionals prevent catastrophic epidemic outcomes.