Poliomyelitis in the cynomolgus monkey; further observations on exposures confined to the stomach and intestines, with notes on the fecal excretion of virus

36 exposures of the stomach and intestines of 18 cynomolgus monkeys to large doses of poliomyelitis virus by a method designed to avoid simultaneous exposure of the oropharynx and upper esophagus induced poliomyelitis in only one instance. These observations are to be compared with a previous study in which exposures of the entire alimentary tract including oropharynx and upper esophagus by simple feeding of comparable amounts of the same strain resulted in poliomyelitis in half of the test animals. In the capsule-fed animals virus regularly appeared in the stools during and immediately after the feeding periods but disappeared thereafter excepting in the single case of poliomyelitis, in which it persisted. No evidence of resistance to subsequent intracerebral inoculation was observed in the uninfected capsule-fed animals.

A virus recovered from the feces of poliomyelitis patients pathogenic for suckling mice

A virus has been recovered from the feces of two children having symptoms similar to those of poliomyelitis. The virus is pathogenic for suckling mice and hamsters but not for rhesus monkeys. It induces striking lesions in the skeletal muscles of the experimental animal but not in the central nervous system. Other viruses inducing similar signs and lesions in suckling mice have been isolated from several other outbreaks of a poliomyelitis-like disease, including one large urban epidemic.

Antibody response of patients with poliomyelitis to virus recovered from their own alimentary tract

Of 20 strains of virus recovered from 40 patients with poliomyelitis only 9 possessed a titer of 10^–3 or more, permitting significant quantitative neutralization tests in monkeys. Seven of the 9 high titer strains were derived from patients whose illness was ultimately paralytic, and tests with their undiluted sera indicated that the acute phase as well as the 3 month convalescent specimens neutralized maximum amounts of the patient's own virus. However when varying dilutions of the sera were tested against a single dose of virus, it was found that the antibody was present in lowest concentration early after onset and progressively increased in titer over a period of weeks during convalescence. The 2 remaining high titer strains were recovered from patients with a non-paralytic illness, and in both of these the acute phase sera were without significant amounts of antibody for their own virus. Antibody was demonstrable at 14, 28, and 92 days after onset in one of these patients, while the other had none at 1 month and only a minimal amount at 3 and 8 months. Tests with the Lansing virus on the same sera, clearly established the specificity of the antibody response to the strain of virus recovered from each patient under investigation. Five of the 9 patients, whose sera were studied with both viruses, had no antibody for the Lansing virus during the acute phase and none 3 months later. Two had antibody during the acute phase but serum dilution tests showed no increase in titer in the 3 month convalescent specimen. In 2 others, who were without antibody for the Lansing virus during the acute phase but had it at 3 months after onset, it was possible to show that this antibody appeared later than 1 month after the illness and that the virus recovered from these patients during their illness was not antigenically of the Lansing type.

An electron microscope study of nerves infected with human poliomyelitis virus

Sciatic nerves of rhesus monkeys infected with CAM and Wis. '45 strains of human poliomyelitis virus were fixed in formalin, sectioned, fragmented, and examined in the electron microscope. Most of the neurotubules of nerves infected with the CAM strain have normal appearance but a very small number show the presence of dense particles irregularly aligned within the edges of the neurotubules. The diameters of the particles range between 160 and 500 Å, the mean being 330 Å. The particles were found in regions along the nerve which varied with the time after infection, indicating a central movement of the morphological alteration of the order of 2 mm. per hour. Relatively abundant dense particulate material was found in nerves infected with Wis. '45 strain virus and the particles were chiefly attached to the edges of the neurotubules and in the adjacent areas of the field. The dense particles appear to be associated with the virus infection but no further characterization is possible at this time.