What are the major reasons for concern over the possibility of a pandemic?
Computer modeling in Thailand suggests the possibility, with immediate early aggressive coordinated international intervention, of stopping a potential pandemic strain. This would be analogous to quenching a small fire with forest-fire potential. Once human-to-human transmission reaches a major metropolitan area, however, the past history of influenza pandemics indicates that spread throughout the entire world can be expected to occur in only a matter of weeks. Most health authorities doubt that it will be able to be stopped, once a pandemic is underway, only mitigated, at best. A pandemic virus will be spread rapidly by the coughing or sneezing by infected persons. Unlike SARS, individuals shed the virus for about two days before symptoms appear. Asymptomatic air travelers will be very difficult to screen because spread may occur without fever. Attack rates during a pandemic, by definition, reach 25-35% of the total population. Even with a mild pandemic virus, such as occurred with th
