Vaccine-associated paralytic poliomyelitis. Regional case series and review

We present 10 cases of vaccine-associated paralytic poliomyelitis from Washington State to better acquaint physicians with the signs and symptoms of this condition. Diagnosis may be delayed, and milder cases may be overlooked, owing to the unfamiliarity of physicians with the condition. Based on these 10 cases, a rate of 6.4 cases (recipient plus contact) per million live births is estimated for the period 1966 through 1988 in Washington. This rate is higher than calculated for the nation as a whole. The explantation for this difference is unknown, although several possibilities exist, including case clustering.