Polio has probably caused paralysis and death for most of human history. The oldest clearly identifiable reference to paralytic poliomyelitis is an Egyptian stele (stone engraving) over 3,000 years old. Cases of poliomyelitis tended to be rare in ancient times, though, as sanitation was generally poor. With improvements in waste disposal and the widespread use of indoor plumbing in the 20th century, epidemics of polio began to occur with regularity in the developed world, primarily in cities during the summer. Because sewage was dumped away from the drinking water supply (a development which helps combat a number of other diseases, including cholera), babies were much less likely to be infected with polio and gain protective immunity. As the children got older and began playing with others, swimming in public pools, and going to school, they were more likely to be exposed to the virus, which was then more likely to cause paralytic poliomyelitis.

H.L. Mencken writes of polio epidemics occurring virtually every summer in Baltimore during his childhood in the late 1890s, and this tragic cycle continued through the 1950s. Though the virus only paralyzes about 1% of the individuals it infects (most infections are asymptomatic or result only in a self-limiting diarrhea), it tends to be transmitted very easily under the right conditions. One percent of all children in a large city translates into thousands of cases, and the emotional and economic impact of such epidemics was staggering. The brochure below was distributed a few years before the vaccines were available.
 

By the time of the Great Depression, paralytic poliomyelitis was perhaps the most feared disease known. Polio struck fast, there was no cure, and it crippled its victims for life. Hobbling on crutches, rolling in wheelchairs, or lying immobile in giant iron lungs, the legions of sufferers accumulated from year to year. Even the exact mechanism of polio's transmission was a hotly debated subject for many years, so many areas were placed under strict quarantine when cases of the disease began to manifest themselves. Only the fear surrounding AIDS can rival the feelings people had about polio in the first half of this century.

President Franklin Roosevelt declared a War on Polio during his administration, and the tremendous resources of postwar America were brought to bear on the problem of developing a vaccine. From the beginning of this effort, it was clear that such a vaccine was at least theoretically feasible, as contrasted with such pathogens as malaria and HIV, where no such assurance exists. In the early 1960s, the work bore fruit, first with the Salk vaccine, and soon after with the Sabin virus strains.

Salk used chemical and heat treatment to kill poliovirus, then injected this inactivated virus into patients. The proteins of the destroyed virus "taught" the patients' immune systems to recognize polio, and they were then protected from subsequent infection. Sabin's approach was to grow the virus in the laboratory under a variety of conditions, allowing it to accumulate mutations. Ultimately, this resulted in an attenuated virus which could be given to a patient orally. The weaker virus replicates normally in the intestine, but cannot grow well enough to invade the central nervous system. Once again, the immune system "learns" to recognize polio, and this confers protection.

Once the Sabin and Salk vaccines were proven effective, the disease was rapidly eradicated throughout most of the industrialized world. The economic effect has been enormous; it has been calculated that the polio vaccine pays for the costs of its development approximately every three weeks. The benefit to the United States alone for this single breakthrough runs into the trillions of dollars. The social impact has been incalculable. The crutches, wheelchairs, and iron lungs of polio victims have at last been banished from children's and parents' nightmares, at least in the developed world.

Recently, the World Health Organization embarked on a campaign for the worldwide eradication of polio. If this plan is completed successfully, it will conclude the second deliberate destruction of a virus by humans, and stand as the final victory in Roosevelt's other war.

• Polio and the era of fear For a time, polio was the most feared disease in the developed world. This book tells the story of that time.
  
   
• Halstead, Lauro, "Post Polio Syndrome," Scientific American, April 1998, pp. 42-47. An excellent review of the current state of knowledge about this perplexing condition.  The full text of this article is available on the Lincolnshire PPS site.
  
   
• The Story of Polio The Web site of a PBS special about the history of the disease.
  
   
• The Last Child  The site for a new documentary film entitled "The Last Child," about the global polio eradication effort.

• Support Groups and Centers

• International Polio Network A group which provides information about post-polio syndrome as well as ventilators. Based in St. Louis, Missouri.

• Lincolnshire Polio Site Maintained by Chris Salter in the UK, this is an outstanding site for up-to-date information about PPS and polio.  Includes the full text of the Halstead article referenced above.

• Post-Polio Institute at Englewood Hospital A PPS treatment center based in Englewood, New Jersey, with an informative, straightforward Web site that should be useful for anyone interested in learning more about this condition.

• Portuguese Post-Polio Association A post-polio support group based in Portugal, for those readers located on that side of the Atlantic.  Since nobody here at PICO reads Portuguese, we cannot provide any further comment on the site's content.  It does produce a pop-up window with an advertisement in English when you get there, though.

• Medical Information and News

Always take medical information on the Internet with a large grain of salt, and if you think you need treatment, see a doctor in person.  With that in mind, here are a few information  sites that might be of interest.
 

• End Of An Era: Polio Vaccine Pioneer Jonas Salk Dies An obituary.

• Johns Hopkins University Infectious Disease No, Hopkins has not become a virus. This is an informative site with information about a variety of conditions, including post-polio syndrome.

• Post-Polio Syndrome Central A meta-site listing Internet resources for PPS patients. Also includes some original content, polls, and surveys, and is the home of the Post-Polio-Med Email List, for conversing with others interested in this topic.

• PPS Information An information and link page about PPS - lots of resources for PPS sufferers and polio survivors. Animation and sound make this a bad site for those with slow modem connections.

• The Albert B. Sabin Vaccine Institute A nonprofit organization dedicated to advancing the vision of Albert Sabin.  This group helps support the development of new vaccines and the distribution of existing ones for a variety of diseases.

• League Table: Action on Polio Updates on various nations' progress towards polio eradication, based on UNICEF data.

• Ending polio - now or never? Timing may be crucial for the destruction of this virus, and this article argues that the current opportunity may not come around again.

• Rotary Club of Wanganui Daybreak The Rotarians have been instrumental in the eradication campaign, and this New Zealand chapter is actively raising funds to continue the effort.

• The Vaccine Site An information resource assembled by the editors of Unisci. The site is conveniently broken into links of interest to parents, medical practitioners, and researchers.

• WHO Polio Eradication Effort From the people largely responsible for the effort, a site about it. We might not always agree with their approach, but we applaud the goal.