Friday, May 29, 2009

Swine Flu and the Pandemic of 1918


The year is 1918. American troops have joined the allies fighting the war raging in Europe. By the end of The Great War over 100,000 American soldiers died. But it was not only bullets, bombs or poison gas that slaughtered them quickly and terribly by the tens of thousands. A ruthless killer too small to be seen by the most powerful microscopes of the age and too illusive to be known by the best scientific minds was responsible for the deaths of half of the U.S. troops killed in the European theater. The killer was influenza.

The influenza pandemic of 1918 killed more humans worldwide in one year than died in the four years of the Bubonic Plaque in the mid thirteen hundreds. Between the years 1918 and 1919, 20-40 million died of influenza. Twenty-eight per cent of Americans were infected, 675,000 of all classes died, the rich and the poor. The flu raced around the world along trade routes and shipping lanes infecting twenty per cent of the population of the planet. It was a true pandemic.

So prevalent was the disease small children skipped rope to this grim rhyme.

I had a little bird,
Its name was Enza.
I opened a window,
And In-flu-enza.


The Centers for Disease Control, (CDC) and other government agencies were aggressive in their response to the so called ‘Swine Flu’ of 2009 partly because of what happened in 1918. The epidemic of 1918 was caused by a variant of flu virus that had not been seen before. As a result those exposed had little or no immunity to this novel virus. Because the Swine Flu virus is also a new strain, government agencies were afraid that millions worldwide could be infected and die just as they did in the early part of the 20th century.

The flu of 1918, like the Swine Flu, first appeared in the spring and like the Swine Flu was mild. So mild it was called the ‘three day fever’. Few deaths were reported and most patients recovered in a few days. The following fall the 1918 flu returned with incredible virulence. Millions were infected and millions died. Many of the affected died within hours or days. People told of visiting a neighbor one day only to find the next day the person was dead.

The so-called Swine Flu is a variety of the Influenza A N1H1 strain similar to the one that caused the 1918 flu, but that does not mean it will be as virulent. Many factors affect the virulence of a flu virus and even though they are the same subtype, they can be very different.

The N1H1 subtype is simply a description of two proteins found on the surface of most viruses and is used to differentiate between different strains of Influenza, such as Influenza A, one of the viruses responsible for seasonal Flu. The H refers to a protein called Hemagglutinin (He-ma-glue-tin-in). The Hemagglutinin helps the virus particle stick to the cell it will infect. There are 16 types. The N refers to an enzyme called Neuramidase (Nur-am-eeh-daze). There are 9 types. The Neuramidase helps the newly formed virus particles release from the surface of the infected cell. This enzyme is inhibited by anti-flu medications such as Relenza and Tamiflu. If the new virus particles stay stuck to the infected cell they can’t go out and infect more cells.

In light of the loss of life in 1918-19, the government was cautious in its approach to this latest novel virus. This is not to say that the Swine Flu will be just like the Flu of 1918 just because there are similarities, such as both being a strain of Influenza A H1N1 and starting out mild in the Spring.

Luckily, unlike the victims of the 1918 Flu, we have effective antiviral drugs, better public health and communication abilities, as well as the capability of producing a vaccine.

Unfortunately these were not available to the millions who died in the 1918 pandemic.

Wednesday, May 20, 2009

Moving to Friday


I am going to move this post to Fridays. Oh, if there is a science subject of particular interest to you let me know via comment and I'll see what I can find.


lyle

Wednesday, May 6, 2009

Robert Malthus and the Irish Potato



In 1798 Robert Malthus published a book entitled, An Essay on the Principle of Population.

As I understood it, the principle stated populations of humans grew in number until food became too scarce to sustain further growth. At this point people were able to stay alive, but just barely. Anything that reduced food production caused starvation until the population dropped to the level the amount of food available could sustain, again just barely. Making the problem worse, he maintained, was that the food supply can only increase arithmetically (1, 2, 3, 4…) while populations grow geometrically (2, 4, 8, 16…).

In everyday terms, Malthus’s Theory states that the population rises to the level of sustainability. Increase the amount of food the population rises, decrease the amount of food and the numbers of people drops.

An example is the potato famine in Ireland.

Around 1590 the potato was introduced to Ireland. By the 1800’s the potato had become the staple crop of the poor with approximately 3 million subsisting on it alone. This was possible because the potato is rich in protein, carbohydrate, minerals, and vitamins including vitamin C. So, while a boring diet, it was nevertheless a healthy one. The Irish poor subsisting on the potato were healthier than the British poor living mainly on bread. The danger for the Irish poor was that the potato increased the food supply and as a result the population doubled from 4 million to 8 million. A large segment of the Irish population was now dependent on a reliable potato crop. This dependency resulted in a disaster of colossal proportions.

In the year 1835, a disease struck the potato crop wiping it out entirely by 1837. Nearly one million starved. The Irish population dropped by 25% due to starvation, disease caused by malnutrition and by emigration, many to America where the food supply was more than adequate for the growing number of people.

This tragedy had been predicted by Malthus. The population had grown as the result of an increased food supply and when that food supply disappeared the population shrunk back to a number that could be sustained by the available food supply.

There is a lesson to be learned here for our rapidly growing world population. Feeding people is not the way to save lives, as the more you feed the more you have to feed until you simply cannot feed them all. Of course, we cannot let people starve as a way of helping them, but we must come up with some means of stabilizing our population. To my mind it is the greatest threat our planet faces. Nearly all the problems we face, energy shortages, food shortages, disease, war, pollution, and destruction of habitat are made worse by our rapidly growing population.

And despite what many say, this is not a problem technology can solve. Eventually old Robert is right.