The last major flu pandemic occurred in 1968. In comparison to SARS killing 700, more than 30,000 people died in the USA alone (in the 1968 flu). Globally, some 1 million succumbed to the disease, meaning probably more than 50 million were infected worldwide.
The preliminary numbers coming out of this particular virusÃÔ origin, Mexico, are not necessarily accurate. However, if it turns out the first data are accurate, big trouble is on the horizon. Mexico City health authorities say nearly 1,600 suspected cases have been reported, with more than 140 dead. That translates into a 7-plus-percent mortality rate. SARS carried about a 9-percent death rate. But more important, the mortality rate in the 1968-1969 flu pandemic was very low at less than 3 percent. That means that the death potential now in 2009 is at least twice as high as in 1968. Further, the ability of this current strain of flu to spread rapidly seems to be much greater than in previous contagions.
From Reuters: Ūt [virus] has been found in several places and among people who had no known contact [with infected persons]. This suggests there is an unseen chain of infection and that the virus has been spreading quietly. As of this writing, cases have been identified in as far-flung places as the USA, Scotland, New Zealand and Spain. Suspected cases are also reported in France, Norway, Germany, Sweden and Israel.
A week from now, as more information emerges and is confirmed, it may be that this turns out to be an isolated and short-lived concern, a minor footnote to the other ÅÄrisis of 2009.
But if not . . .
SARS had two unique qualities that aborted a pandemic. The disease was quickly debilitating. People who contracted the illness were forced to seek major medical help very soon after the virus bloomed. SARS was not quiet. Second, the mode of transmission was clear: airborne from infected person to the healthy.
Because of these two factors, the duration was short, about nine months. By contrast, the 1968 flu pandemic lasted more than one year.
This current strain of Mexican swine flu does not create dramatic symptoms at the beginning. Those who contract the virus suffer the mild effects of other more benign virusÍÔlight fever, cough, minor body aches. It is just these symptoms that make this virus so dangerous. By the time a person becomes very sick, he may have spent days in normal contact with coworkers, family members and strangers, spreading the disease easily. And the mode of transmission is not clear at this point.
For its ease of contagion and hidden symptoms, the World Health Organization has raised its Pandemic Alert level to 4 (out of 6) for the first time since this scale was revised in 2005. Level 5 means that we have a full-blown global epidemic. We will know by the end of next week what the rest of the year will be like.
If, and this is a big if, this turns serious, what is happening in Mexico is a foreshadow of what is to come. Mexico suspended all schools nationwide until May 6, affecting over 50 million students. Tourist travel is over until this situation is resolved, as the European Union has issued a strongly worded travel advisory for both Mexico and the USA. On the other side of Mexico, the resort town of Acapulco ordered all bars and nightclubs closed.
