Thirty-five hundred years ago an Egyptian craftsman carved a bas relief stela depicting a young man with a crippled, withered leg. Egyptologists believe the young man represented in the stela was a priest. He is supporting himself with a staff held under his arm much as one might use a crutch. The deformity of his shrunken leg is typical of that seen following paralysis in childhood. The young man probably had the disease we call poliomyelitis- polio, for short as a child.
Moving forward in time about 1500 years, the early depiction in stone of a paralyzed leg from Egypt is joined by descriptions of the famous Greek physician Hippocrates and his Roman disciple Galen, both of whom wrote about acquired club foot in terms that suggest they may have been describing polio. Across thousands of years, our ancestors tell us that polio is an ancient curse of humankind. Today, we stand on the threshold of a victory that will soon see this ancient curse banished from the earth.
If polio has been present among people since antiquity, it has kept a quiet profile during most of history. Sporadic accounts of paralysis undoubtedly due to polio appeared during the eighteenth century, and in 1813 the first clear medical description of polio was published by an Italian surgeon Giovanni Bartista Monteggia. However, the disease of that time was not that which swept across Europe and North America in more modern times. Until the latter part of the nineteenth century, polio was an endemic infection, common and always present, occurring early in life, with paralysis as an infrequent complication. In fact, the infection may have been very common at that time, for paralysis in infants with polio is not usual, and only the few with paralysis were noted. Infantile paralysis, the name given to polio by a German orthopedist, Jakob Heine, in the mid nineteenth century, quite accurately denominated the disease as it was then seen by medical practitioners. Heine described this disease as one of infants between six and 36 months of age. Thus polio smoldered, by-and-large an unrecognized and unimportant but common infection of early childhood, a cause of fever, headache, and malaise, but only occasionally a cause of paralysis.
It is important to distinguish between infection and disease, a point that comes up repeatedly in this discussion. Infection refers simply to the establishment and growth of the infectious agent within the body. This may or may not be associated with disease, which is a deviation from the normal state of health. Infection often occurs in the absence of disease. Infection without disease results in immunity.
During the nineteenth century, an increasing number of small outbreaks of polio occurred in which adults were affected. In 1887 a major epidemic hit Stockholm. Fourty-four cases of paralytic polio occurred in a city that had previously experienced one or two cases a year. Investigating this epidemic, Karl Oskar Medin realized for the first time that the paralytic cases were only a small part of the epidemic, and that persons with only mild illnesses were spreading the disease to others. About this time André Cornil, a French pathologist, performed the first autopsy on the brain and spinal cord of a patient who had paralytic polio. Subsequently, Jean Martin Charcot, his colleague and one of the founders of the science of neurology, extended that first autopsy study and demonstrated that the site of tissue destruction was in the part of the spinal cord known as the anterior horn, the area of origin of nerve cells controlling muscles.
As the twentieth century dawned, epidemics became the usual pattern of polio in the industrialized countries of the temperate zones, with outbreaks occurring regularly every summer and early fall. The age of the persons afflicted also increased. Polio is a different disease in young children and in adults. In children, it is usually a mild illness, often unrecognized, and infantile paralysis is uncommon among those infected with poliovirus. However, this mild infection produces life-long immunity against further attacks by the same virus. Polio in adults is more severe, and paralysis occurs much more frequently in this age group.
Poliovirus is excreted in large quantity by infected individuals in their stools. In communities where sanitary systems are primitive, poliovirus circulates readily in the population, and almost all children are infected at a young age and become immune. This pattern of spread was usual throughout the world prior to the industrial revolution and continues to the present in developing countries. In modern times, improved sanitation has reduced transmission by the fecal-oral route and has left adults nonimmune in developed countries. Transmission of infection usually required close contact, and the source of virus was commonly the throat. With the shift to older patients, paralysis became a more frequent complication of polio. Even though fewer cases of infection were occurring, the disease's manifestations were more severe and more alarming. At the same time, polio became a seasonal disease, but it is not clear why.
The mysterious seasonal occurrence of polio epidemics in the industrialized countries, the lack of a clear understanding of how the infection was transmitted, the crippling nature of the disease, the increase in the involvement of young adults, along with a greater number of patients requiring the use of the fearsome apparatus, the "iron lung" or Drinker-Collins respirator, all led to a great concern about the disease and sometimes panic among the public. Not surprisingly, control of poliomyelitis became a major priority during most of the early twentieth century. Swimming pools, beaches, playgrounds, and movie theaters were closed during summer months. School openings were delayed until each summer's epidemic had passed.
An interesting feature of polio is the so-called provoked, or trauma-induced paralysis. It was observed that children who received inoculations such as DPT early in the course of poliovirus infection were more likely to become paralyzed and the paralysis more likely to occur in the limb that had received the inoculation. A particularly distressing form of this phenomenon was that which followed tonsillectomy and resulted in bulbar polio in which the nerves controlling the muscles of breathing and swallowing were affected. A dramatic example of this effect occurred in a family whose five children all had their tonsils removed on the same day. All of them developed polio, and one died. Once this phenomenon was recognized, tonsillectomies were not performed during the polio season.
~~Polio -ed- Thomas M. Daniel and Frederick C. Robbins
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