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Show Your Doctor Says . . . I The following U one of a tenet of or-tUla or-tUla written by mtmbcrj of the Utalx I Stale Medical AJOcuirion and published in I cooperation wild your local newspaper. I These article are icKeduled to appear every other week throughout the year in an effort to better acquaint you with problemi of health, and designed to improve the well-being of the people of Utah. Poliomyelitis Poliomyelitis is a very old disease of mankind. Evidence is available that it existed at least 3700 B.C. Experimental work did not begin, however, on this disease agent until 1908, when Land-steiner Land-steiner and Popper were successful success-ful in transmitting the disease to monkeys. Naturo of the Virus The disease-producing agent is a virus belonging to the same group of disease agents that produce pro-duce measles, mumps, yellow fever, influenza and encephalitis. Viruses differ from bacteria in several respects. Bacteria, germs or microbes, cause diseases such as scarlet fever, boils and abscesses, ab-scesses, diphtheria, whooping cough and a host of other types of infection. Bacteria can be seen with the aid of an ordinary microscope. micro-scope. Bacteria will grow, not only in the body, but also may be cultured cul-tured on lifeless food such as meat broth, milk, and various other foodstuffs. Viruses, on the other hand, are invisible under the ordinary or-dinary microscope and will pass through filters that hold back or retain bacteria. The "polio" virus is one of the tiniest known disease agents, being a little less than one two-millionth of an inch in diameter. The polio virus, like other viruses, fails to grow unless living tissue cells are available for food. This virus has a special attraction to nerve cells of the spinal cord and the base of the brain. Destruction of these nerve cells causes paralysis. Cultivation of the Virus Man is, the only naturally susceptible sus-ceptible host. Monkeys can be given the disease experimentally but guinea pigs, rabbits, rats, etc. are completely resistant These latter resistant animals can be injected with thousands of monkey paralytic doses of the virus, with "no illness whatever developing. Monkeys, therefore, are the only dependable experimental experi-mental animal that can be used for the study of this disease. Since monkeys cost $35 each, and their care is expensive, the cost of poliomyelitis research is exorbitant. exorbi-tant. The dimes donated to the National Foundation for Infantile Paralysis has made possible the money for research and purchase of these expensive experimental animals. Another method of virus culture has been devised by Dr. J. F. Enders of Harvard University. This method consists of growing monkey or human tissue cells in a special fluid in test tubes. Virus is added to these growing cells and the virus attacks and destroys the cells in from five to seven j days. This tissue culture method; is less expensive than using! monkeys, but certain kinds of research re-search must still require the animal ani-mal testing method. This tissue! culture virus is the one which is being used to develop a preventive preven-tive vaccine. Where the Virus is Found The virus of poliomyelitis may be isolated from the throat and from the fecal material of persons per-sons ill with the disease, and from nervous tissue of persons dying of the disease. The virus may also be isolated from sewage, particularly during the summer months. The virus seems to be quite hardy and resistant, staying alive in sewage water for several months. It can be stored for many years in the dry-ice box. The virus is, however, quickly destroyed by boiling a minute or two, and also is destroyed by strong chemicals such as formal- dehyde. The virus is not affected by any presently known anti-, biotics, such as penicillin, aureo-; mycin, etc. 1 Types of Viruses ) , Three types of poliomyelitis viruses have been isolated. Each one produces the same type of " disease in man, there being no distinguishing features of the disease with any of the types. Any one of the three types may produce death in one person; another an-other person may be severely paralyzed, while again with the same virus type, another individual individ-ual develops such mild symptoms that a diagnosis is impossible. On recovery from the disease, the immunity im-munity produced by Type 1 will offer no immunity for Types 2 or 3. Therefore, the immunity produced pro-duced in man or monkeys is specific spe-cific for each type and theoretically theoretic-ally one could have the disease three times. Recovery from one type will produce a lifelong immunity im-munity for that specific type. About 70-75 of the adult population have had the disease in such a mild form that they have not been aware of the illness, ill-ness, and are immune to the specific spe-cific type which produce the disease. |