Impact

In the past, new strains have generated pandemics causing high death rates and major disruptions to society. Although healthcare has improved in recent decades, epidemiological models project that today a pandemic is likely to result in 2 to 7.4 million deaths globally. In developed countries alone, accounting for 15% of the world’s population, models project a demand for 134–233 million outpatient visits and 1.5–5.2 million hospital admissions. However, the impact of the next pandemic is likely to be the greatest in developing countries because of different population characteristics and the already strained healthcare resources. If an influenza pandemic occurs, the following is to be expected:

• Given the high level of global traffic, the pandemic virus may spread rapidly, leaving little or no time to prepare. A new pandemic based on the lethal H5N1 avian flu virus originating in Asia would take a mere two weeks to arrive in Europe.
• Vaccines, antiviral agents and antibiotics used to treat secondary infections will be in short supply and will be unequally distributed. It will take several months before any vaccine becomes available.
• Medical facilities will be overwhelmed.
• Widespread illness may result in sudden and potentially significant shortages of personnel required to provide essential community services.

Simulation of spread of a Great Britain influenza pandemic
This movie shows the first 140 days of a pandemic in Great Britain, assuming a moderate level of transmissibility (R0=1.7). The movie starts on day 40 of the global pandemic, just before the first cases entering the country. The video runs at the rate of three days model time per second of video time. Grey scale represents population density of uninfected, susceptible individuals. Red represents density of infected individuals, and green represents areas where the epidemic is over. 58.1 million individuals were modelled in the GB simulation. Source: Strategies for mitigating an influenza pandemic Neil M. Ferguson1, Derek A. T. Cummings2, Christophe Fraser1, James C. Cajka3, Philip C. Cooley3 and Donald S. Burke2 Published in Nature http://www.nature.com/nature/journal/v442/n7101/abs/nature04795.html

Simulation of spread of a United States influenza pandemic
This file shows the first 170 days of a pandemic in the United States of America, assuming a moderate level of transmissibility (R0=1.7). The movie starts on day 40 of the global pandemic, just prior to the first cases entering the country. The video runs at the rate of three days model time per second of video time. Grey scale represents population density of uninfected, susceptible individuals. Red represents density of infected individuals, and green represents areas where the epidemic is over. 300 million individuals were modelled in the US simulation. Source: Strategies for mitigating an influenza pandemic Neil M. Ferguson1, Derek A. T. Cummings2, Christophe Fraser1, James C. Cajka3, Philip C. Cooley3 and Donald S. Burke2 Published in Nature http://www.nature.com/nature/journal/v442/n7101/abs/nature04795.