Medicine / Infectious Disease

Swine/Pig/Pork Flu
Matthew Vasey, MD
Editor, New York Journal of Style and Medicine

Imagine a spherical virus with a variety of "things" called glycoproteins on its surface. These dangerous things as far as their ability to infect humans or antigenicity is concerned, are called hemagglutinin (H) and neuraminidase (N). Influenza A virus is notorious for its mutations or genetic reassortments of these antigenic characteristics. Small scale or subtle gene changes that lead to more localized outbreaks of the flu are called "antigenic drifts". Large scale or significant gene changes can lead to global outbreaks, or pandemics are called "antigenic shifts". The impact on the population is contingent on how infective the viral surface is and how susceptible we as humans are. If you have a flu strain that infects pigs and it modifies an infectious component which all of a sudden can infect a human, there is now a flu strain that the human population, more importantly our immune system has never seen before. If this new flu strain happens to be deadly to humans and easily spread catastrophe ensues. Historically, this happened three times in the 20th century along with a couple "scares".

In 1918, the "Spanish Flu" infected 20-40% of the world's population and over 50 million people died, 575,000 of whom were in the U.S. (2) Other less catastrophic strains followed in 1957 and 1968 killing about 70,000 and 35,000 people respectively, in the U.S. (2) These subsequent pandemics to the Spanish Flu contained identical genetic portions and in essence were "children-like" (1). For obvious reasons, there is tons of medical effort devoted to influenza. There may even be a Flu Twitter page or Fantasy Flu coming soon as there is weekly Flu statistic updates posted by the Center for Disease Control. (3)

The best things to do as far as prevention is just some common sense things, like hand washing and avoiding sick people. Eating pig is of no concern. There's tons of information out there and I'm sure people in affected areas are very anxious. Fortunately, the immune system is made for this. Typical stuff to watch out for is fever, cough, sore throat, body aches, headache, chills, and fatigue. There are medicines recommended for this pig flu mentioned in the news. Unfortunately a flu pandemic scare, television and internet (nyjsm.com now included) are the perfect storm for panic. If you're concerned, educate yourself and/or contact your health care provider of choice. For all the latest action, check out the Center for Disease Control website, www.cdc.gov!

REFERENCES:
Belshe RB, The Origins of Pandemic Influenza - Lessons from the 1918. Virus N Engl J Med 353:2209, November 24, 2005
http://www.pandemicflu.gov/general/historicaloverview.html
http://www.cdc.gov/flu/weekly/