(Picture from Mexico Day of the Death)
"This swine flu, meanwhile, does seem to spread easily by airborne transmission. But how deadly is it? Despite the 100-plus deaths in Mexico, we don't really know. And that's why epidemiologists are working frantically to figure out the Mexico mystery: Why do the death rates there appear to be so much higher than those in the United States? In Mexico, it has reportedly killed about 100 of the 1,600 official suspected cases; elsewhere, it has appeared to take a far milder course, with zero deaths out of approximately 300 instances. There are several possible explanations for this discrepancy—any one, two, all, or none of these ideas could shed light on how deadly this virus might prove. In order of ascending likelihood for Mexico's higher mortality:"