POLIOMYELITIS IN THE CYNOMOLGUS MONKEY

Abstract

Using a modification of the Wells apparatus for administering minute infective particles (droplet nuclei) suspended in air, a series of cynomolgus monkeys and another of rhesus monkeys were exposed to poliomyelitis virus by inhalation. Without olfactory blockade, infection was obtained by the olfactory nerve pathway in 6 of 7 cynomolgus and in 5 of 7 rhesus monkeys. When the olfactory mucosa was blockaded with ZnSO4 soln., 4 of 10 cynomolgus and 2 of 35 rhesus monkeys developed the disease, without lesions in the olfactory bulbs (serial sections). The neural pathways of infection were demonstrated in 2 cynomolgus monkeys to have been the 5th cranial nerve and the evidence was suggestive for this route in a 3d. In a 4th, the pathway was the nasopharyngeal sympathetics. In each case, the centripetal passage of virus could be traced into the appropriate peripheral ganglia and thence into the central nervous system. The route in the rhesus was not accurately detd.; in one it may have been by the 5th nerve. Observations in a number of monkeys of both vars. exposed but not showing clinical manifestations of disease, indicated that the Gasserian ganglia were almost constantly involved; the cervical sympathetics less and the celiac ganglia still less frequently. The peripheral ganglia are important intermediate stations in the route of penetration from the body surfaces. Comparison with a previous study suggests that infection occurs with greater ease by inhalation than by ingestion of virus. The air-borne aspects of poliomyelitis infection deserve serious consideration.