Not since the panic of 1976, when a Fort Dix, New Jersey soldier died and four of his fellow recruits became ill, has there been such attention paid to swine flu.  The 1976 “outbreak” triggered a massive effort from the US government to immunize the entire population. The pandemic never materialized despite only 24 per cent of the population receiving the vaccine, and some criticized our government for making much ado about nothing.  Moreover, there were over 500 cases of Guillain Barre Syndrome attributed directly to the vaccination.  Are we currently heading down the same path, or is there good reason to be concerned about an emerging epidemic?

Each year, anywhere from 250,000 to 500,000 people die worldwide as a result of influenza. So what is so different about the swine flu? In 1976, scientists were very concerned because the swine flu isolated from the Fort Dix soldiers closely resembled the flu strain responsible for the pandemic of 1918 that killed countless victims worldwide. Unlike the human influenza A strains that circulate each year, and for which the World Health Organization develops annual vaccines, the swine flu’s primary host is the pig, and is an unknown entity without a “track record” of virulence. As such, epidemiologists do not know what to expect. Generally speaking, new flu viruses are harder for the immune system to defend against, so they can reproduce rapidly and overwhelm the body’s defenses. Ironically, the body can even overreact to a new virus- the so called “cytokine storm”- which may lead to grave illness or death.

The seriousness of the current swine flu from Mexico has yet to be determined.  Several dozen cases have been reported in five states over the past few days, but no one is yet critically ill.  On the other hand, there are already over 140 deaths reported in Mexico from (presumably) the same strain.   History does not help us. In 2007, there was a little publicized outbreak of swine flu in the Philippines that resulted only in mild illness. There were also about a dozen cases of swine flu reported in the United States between 2005 and 2009 – none of them lethal.

A pandemic has three features- the ability to spread rapidly among humans, the ability to cause serious illness in a high percentage of those infected, and novelty in the world of flu viruses.  So far, the Mexican swine flu has proven to only have one of these features- it is a strain not previously identified. We will be watching (and posting) as this story unfolds.