Patterns of Increase and Spread of Polioviruses in Monkeys after Inoculation into Traumatized Tissue. ∗

Summary

Four strains of type 1 polio-virus were injected into loose connective tissue at the base of lesions created 3 days previously by excision of 1 cm² of skin of one thigh. Viral content of serous exudate from inoculated lesions and from uninoculated skin lesions on the scalp and the opposite thigh was determined. The Chesterfield Inlet and Iberia viruses were chosen as field strains that were epidemiologically virulent and avirulent respectively. The Mahoney and LSc are well known laboratory strains of high and low virulence. Less than 200 TCID₅₀ of Mahoney and Iberia viruses were required to infect these lesions. Infection occurred irregularly with LSc virus injected in amounts of 4,000 and 60.000 TCID₅₀. The avirulent LSc virus failed to appear in the blood or in uninoculated lesions. The other 3 strains increased in inoculated lesions and in all uninoculated lesions. Although virus appeared to multiply extensively at the lesion site, healing progressed normally; and there was no evidence of local tissue injury. The decrease and disappearance of virus in all lesions of any one animal was essentially parallel. Paralysis occurred in the 2 monkeys infected with Mahoney virus, in 1 of 2 infected with the Chesterfield Inlet virus, in 1 of 4 infected with Iberia virus, and in none of the 4 infected with LSc virus.

The expert assistance of Mrs. Sally A. Allard and Miss Kama Sundsted is gratefully acknowledged.