The Poliovirus

Excerpted from
The Polio Paradox: Understanding and TreatingPost-Polio Syndrome and Chronic Fatigue
By Richard L. Bruno, H.D., Ph.D.

Each plate has "mountains" rising outward, and these create "canyons" on the virus surface. The canyons are important because they are where the poliovirus attaches itself to cells in your body. But the poliovirus doesn't attach to and damage just any cell. It is a "guided missile" that does one thing: seek out, damage, and destroy the neurons that "activate" you-the ones that activate your brain and muscles. The poliovirus is the perfect human "OFF switch."

And there isn't just one poliovirus. There are three different types, each named for the location where it was found, either in a city or inside a person: Brunhilde, Lansing, and Leon. The three types are different because your immune system makes a different antibody for each. But they are also different in terms of how common they are and their ability to cause harm. Almost all of history's polio epidemics have been the result of Type I poliovirus, which caused leg, and, and sometimes breathing muscle paralysis. The Type II virus seems to have been least likely to cause paralysis but may have damaged the "stem" at the bottom of the brain, just above the spinal cord, and was responsible for huge outbreaks of "nonparalytic" polio and something called the "Summer Grippe," about which we'll learn in chapter 17. Type III poliovirus, the most rare, also caused leg and arm paralysis but was most likely to produce so-called "bulbar" polio, in which the bulb or stem of the brain was severely damaged. This damage caused difficulties with swallowing, breathing, and blood pressure that were sometimes fatal.

It's most likely that you were infected with only one type of poliovirus, probably Type I, which caused all of your symptoms. Some polio survivors had two types at the same time, while a very unlucky few were attacked by one type in one year and then infected with a different type later in life. You could have gotten polio twice or even three times, because in the days before vaccine the body needed to be exposed to all three polioviruses to develop antibodies to protect against each one.

Even though there are only three types of poliovirus, there are at least fifty variations of the types, called strains. The existence of different strains has nothing to do with antibodies but every thing to do with virulence, strains' differing ability to multiply in your body, to get inside your neurons and damage them. The fact that some poliovirus strains actually do little or no damage to your neurons allowed Albert Sabin to develop a polio vaccine that contains all three types of polioviruses that are live but non virulent, that is, able to cause your body to produce antibodies, but unable to get inside your neurons to do damage. The existence of dozens of different poliovirus strains makes it clear that polioviruses mutate inside people and can change their virulence. In fact, experiments in animals show that the passage of poliovirus-infecting one animal with a poliovirus, having that animal infect another, and so on-can increase virulence. As the polioviruses passed from person to person during the middle of the twentieth century, they apparently became more virulent, causing more paralysis and killing more people in 1950 than they did in 1920, a story that I'll tell in the next chapter.

Over the Teeth and Past the Gums

The first question you may ask is how you came to be infected with any of the polioviruses. No, it wasn't spoiled milk, filthy flics, or being mean to your sister. The polioviruses belong to a nasty family of seventy-two viruses called enteroviruses, so named because they grow in your "entrails," your intestines. You were infected with the poliovirus when you came in close contact with someone who was already infected and some of his or her saliva or intestinal secretions found their way into your mouth. From there the poliovirus went on a ten-day, unnoticed tour of your insides. It first moved into the spongy tissue of your tonsils and began to multiply. While poliovirus was growing in back of your throat, it also moved downward, into and through your stomach, and reached your small intestine. There it entered Peyer's patches, miniature cave-like lymph nodes in the wall of the intestine, which provided a warm and welcoming way station in which the poliovirus multiplied like mad. Also inside the Peyer's patches are white blood cells called monocytes-the same cells of which you have too many if you get mononucleosis. Sticking up from the surface of the monocytes are structures essential for the poliovirus to do its dirty deeds: poliovirus receptors, miniature proteins that look like crooked fingers and fit perfectly into those canyons on the surface of the virus.