The distribution of poliomyelitis virus in cynomolgus monkeys following oral administration, tonsillectomy, and intramuscular injection of diphtheria toxoid

Summary and conclusions

In cynomolgus monkeys fed the Mahoney strain of type 1 poliomyelitis virus, and bled to death after varying intervals following administration of the virus, several tissues were examined for the presence of virus by the tissue culture method using HeLa cells. The tonsils were found to be the primary sites of multiplication of the virus, from which viraemia regularly developed and was demonstrable from the 5th to the 8th day after feeding. The virus was demonstrated in several organs, i. e. spleen, liver, muscle tissue, lymph nodes, gastro-intestinal wall, nerve plexus and peripheral ganglia during the period of viraemia. The wall of the colon, however, contained already virus before viraemia was demonstrable. The presence of virus in the wall of the gastro-intestinal tract, and faecal excretion were only transitory, so that the intestinal phase does not seem to be very important in the cynomolgus monkey. Since the virus could be demonstrated in the central nervous system as late as 3 days after the last day of viraemia, it is suggested, that the CNS might not be invaded by direct haematogenous spread, but by secondary neural spread from the haematogenously invaded peripheral nerves and ganglia.

In cynomolgus monkeys fed the Saukett strain of type 3 poliomyelitis virus immediately before and after tonsillectomy, the virus was shown to be present in the glossopharyngeal nerve before the period of viraemia. This suggests that bulbar forms after tonsillectomy may be a result of primary neural spread.

In monkeys, which had received one intramuscular injection of aluminium phosphate-precipitated diphtheria toxoid in the right thigh, virus was demonstrated in the corresponding sciatic nerve from the third day of viraemia. This suggests a secondary neural spread of the virus from the haematogenously invaded muscle, which shows a local damage produced by the intramuscular inoculation.