COMPARATIVE FATALITY OF POLIOMYELITIS IN FAMILIES WITH SINGLE AND MULTIPLE CASES

In recent years there has been a reduction in the case fatality of poliomyelitis. In some degree this reduction may be related to better reporting of nonparalytic cases. Improved methods of treatment, particularly artificial respiration and more highly organized medical care, may also have contributed to the decline.¹ Nevertheless, the disease is still a cause of many deaths.² Epidemiological investigation of some of the specific factors that influence fatality reveals an association with clinical type and age.³ Clinical infection is most lethal among those patients with bulbar paralysis, particularly patients over 14 years of age, and the disease is least fatal in those patients under 5 years who do not have bulbar symptoms. The bulbar form of poliomyelitis includes involvement of cranial nerves as well as of medullary centers.⁴ It is the latter group that is responsible for most deaths.⁵ Apparently, involvement of vital medullary