Poliomyelitis is a variable disease, varying from case to case, from epidemic area to epidemic area, from year to year.What happens in one patient does not happen in the next. (1) The foregoing statement by the practiced epidemiologist P. M. Stimson delineates most accurately the history of poliomyelitis. There has hardly ever been an infectious disease that has been controlled so rapidly and extensively, yet despite the worldwide institution of vaccination programs, poliomyelitis remains endemic, with epidemic shifts now and then, in various regions of the developing world (2, 3). This last summer, Israel experienced an outbreak of paralytic poliomyelitis:at least 15 patients were proved to have been affected by the wild type 1 poliovirus (4). In these cases, a definite diagnosis was established by isolation of the virus from the patients' stool and documentation of rising titers of neutralizing antibodies. Approximately 30 other persons had neurologic signs suggestive of poliomyelitis but did not meet the laboratory criteria necessary to establish the diagnosis. The eruption was confined by mass immunization of the entire population up to age 40 with the Sabin vaccine, thus halting the spread of the virulent (wild) virus. This epidemic is relevant to the continuing debate about the relative merits of the killed virus and attentuated live virus vaccines and proves yet again that poliomyelitis, although forgotten by many, is not gone. It therefore warrants consideration.
HISTORY OF POLIOMYELITIS CONTROL IN ISRAELUntil 1949, the attack rate of poliomyelitis in Israel was relatively low, an annual average of 24 cases. Thereafter, accompanying the huge immigration waves in the 1950s and the notorious worldwide poliomyelitis epidemic, the number of cases escalated to approximately 725 per year with an incidence as high as 145 per 100,000 population (Table 1). As many as 90% of 57