ZKEA

Biological Warfare : Biological Terrorism : Emerging Diseases

Influenza, Spanish Flu

It's interesting to speculate about the causes of this global amnesia. Certainly the fact that the epidemic happened in the midst of World War I might have had a lot to do with it. Amid the slaughter of this period an additional 30 million deaths might have been seen as just another tribulation, much less visible than if it happened in peacetime. Another factor might have been a collective psychological need to forget everything that happened during this period and get on with the Roaring 1920s. Why dwell on the past? Certainly there was little profit in it, since this terrifying plague had magically disappeared along with the war.

And terrifying it certainly was. The virus struck quickly. Healthy people would feel mildly feverish in the morning, go to work, and then drop dead on the commute back home. Soldiers in the prime of life fell in the thousands. The virus struck randomly, indiscriminately, killing some and sparing others, in a global pandemic that in a few months reached every corner of the planet. There was no escape and no cure. One could only hope to not become infected.

The Spanish Flu had an odd characteristic: it seemed to preferentially target young healthy people. Usually influenza is lethal only to the old or immune-compromised. Yet this virus was spectacularly deadly to young men and women in their 20's and 30's. This is one of the key reasons why this virus became so interesting to biological warfare researchers of later decades.

What was the origin of the Spanish Flu? It appears to have been an extraordinarily simple thing: a point mutation or recombination in the influenza virus, transforming a normally humble organism into a lethal killer. Influenza is genetically unstable. It has a very high mutation rate, technically known as a fast antigenic drift. This serves the virus well, allowing it to constantly evade the immune systems of its hosts. When you recover from a viral infection your immune system becomes primed to recognize that particular virus in the future, granting immunity from another attack. Normally this translates to lifelong immunity, since your body can now recognize and deal with the given pathogen for the rest of your life. This is why, for example, smallpox and measles can only strike you once. Once you've recovered from such an infection your immune system successfully shrugs off any further attack.

Such is not the case with influenza. Its rapid mutation defeats the immune system, presenting it with a new look each season. This is why people get sick from the "flu" year after year. They're always one step behind in an evolutionary arms race. No matter what the prior state of their immune system, they are always easy targets to the season's new and improved model of virus.

Given this, it's easy to see what happened in 1918. Somewhere in the world a single influenza virus underwent a mutation. This particular mutation, quite by chance, made this particular virus extraordinarily virulent. The virus found an unfortunate human being, reproduced and spread. A chain reaction began, soon engulfing the world.

Thus the Spanish Flu was, ecologically speaking, nothing special. It was just the standard microorganism, doing its standard thing, living the happy life of a influenza virus. Mankind simply got unlucky in this particular cycle.

For this reason, and because Influenza is highly infectious, the disease is very carefully monitored by the World Health Organization (WHO). Health professionals are very aware of its latent capabilities. This close monitoring has caused a few false alarms, including the infamous 1976 "swine-flu" scare. Yet no one doubts that such careful attention is merited.

China is a major source for novel respiratory viruses. This is due to a number of factors, including the dense and mobile population, the temperate climate, social habits (such as spitting), and the proximity to large numbers of poultry and pigs. The influenza virus infects both birds and pigs, and their density in China allows the virus to more-easily recombine and evolve into new forms. Because of this, influenza monitoring systems are particularly focused on this country.

A good example of this dynamic occurred in 2003, when Sudden Acute Respiratory Syndrome jumped into the human species in southern China. From there it quickly spread to the rest of the world. Although not nearly as lethal as the Spanish Flu, the SARS pandemic vividly illustrates the ongoing threat.

Currently there is no effective cure for influenza. However, vaccines are quite effective in preventing acquisition of the disease.

What would happen should another virulent mutation strike? In a world much more populous and interconnected than in 1918? It is not clear that modern medicine and health systems are any better prepared than in 1918. And, of course, influenza isn't the only viral threat we face. There are other viruses out there, some of which are even scarier.

Another source of influenza-angst is bioterrorism. Given the relative simplicity of the 1918 mutation, it is believed that the modern virus could be engineered to incorporate that genome. Why wait impatiently for the next influenza apocalypse, when you can use technology to hurry it along? Because of this, there was a great deal of trepidation when the nature of the mutation was discovered a few years ago. While interesting from a pure scientific standpoint, some asked a fundamental question: might this knowledge be simply to dangerous for mankind to possess? History has not yet provided an answer to this question.

Link: WHO Influenza Surveillance
Link: The 1918 Spanish Flu Pandemic
Link: American Experience with the 1918 Pandemic
Link: The Spanish Flu In Wisconsin - Interesting Local Angle
Link: The 1918 Influenza Epidemic - United States Army
Link: Another good local history
Link: Finding the genetic basis of the 1918 Epidemic
Link: 1918 Epidemic - Gaining Dangerous Knowledge
Link: Bird Flu Outbreak in Hong Kong (WHO, Monitoring Example).
Link: Influenza Evolution, Treatment and Vaccination
Link: Influenza Symptoms And Treatment
Link: Bird Flu Outbreak in Hong Kong (WHO, Monitoring Example).
Link: BCTP - A Possible Influenza And Anthrax Treatment?