EU winter projections: mitigation effect of antiviral treatment

The animation shows the predicted geotemporal evolution of the H1N1 flu epidemic in Europe for the next fall, comparing the no intervention scenario (left map) with a scenario in which mitigation strategies are considered (right map). Simulations for the no-intervention scenario are obtained from the maximum likelihood analysis used to estimate the transmission potential of the new influenza A(H1N1) (see this post for more details) [1]. The antiviral treatment scenario foresees the use of antiviral drugs administered to 30% of the clinical cases within one day from the onset of symptoms.

The maps display the daily new number of cases at a resolution level of ¼° with a color code ranging from yellow (low activity) to dark red (peak activity). The data mapped is obtained from the average value of the daily new number of cases calculated on 2,000 stochastic realizations of the model, for each of the two scenarios.

The timeline shown is from September 1, 2009 to January 31, 2010. The plot at the bottom of the page reports the corresponding country profiles in the same time window. The shaded area corresponds to the 95% CI obtained from the simulations.

Results show that the use of antiviral drugs for treatment of 30% of the cases would result in a delay of the epidemic peak of approximately 4 weeks. This delay would be extremely valuable in providing the necessary time for the implementation of the mass vaccination program.

[1] Balcan D et al, Seasonal transmission potential and activity peaks of the new influenza A(H1N1): a Monte Carlo likelihood analysis based on human mobility. BMC Medicine 2009, 7:45.

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