ABSTRACT
Typical acute hepatitis was reproduced in a human volunteer immune to hepatitis A virus (HAV) after oral administration of pooled stool extracts from presumed cases of epidemic non-A, non-B hepatitis. Markers of hepatitis B infection, anti-HAV IgM, and increase in total anti-HAV level were not detectable in the volunteer's sera during the course of infection. Spherical 27- to 30-nm virus-like particles were visualized by immune electron microscopy (IEM) in stool samples collected during preclinical and early postclinical phases. These particles banded in CsCl at a buoyant density of 1.35 g/cm3. They reacted in the IEM test with sera from individuals who had experienced two non-B hepatitis episodes but did not react with sera from routine anti-HAV IgM-positive hepatitis patients. Intravenous inoculation of cynomolgus monkeys with the virus-containing stool extract resulted in histopathologically and enzymatically confirmed hepatitis, excretion of virus-like particles, and antibody response to them.
Subject(s)
Hepatitis C/transmission , Hepatitis, Viral, Human/transmission , Feces/microbiology , Hepatitis C/immunology , Hepatitis C/microbiology , Hepatitis Viruses/isolation & purification , Humans , Mouth/microbiologyABSTRACT
Solid-phase enzyme-immunoassay (EIA) used for the detection of hepatitis A virus (HAV) often reveals a non-specific activity which can be reduced or fully eliminated in the presence of normal serum. The factor responsible for this activity appeared to be a non-viral EIA-active material (NVEAM) that non-specifically reacted with normal serum of some mammalian species (human, monkey, rabbit, cattle). The HAV and NVEAM have been separated by CsC1 gradient centrifugation, where the HAV banded in a narrow zone at 1.34 g/cm3, whereas the NVEAM could be found in a wider zone with an average density of 1.31 g/cm3. Non-immunological character of the non-specific activity was demonstrated by the inhibitory effect of weak non-ionic detergents (0.05% Tween 20 or bile, 1:500). The conditions for preferential binding of the HAV by immune sera and elimination of non-specific reaction have been determined.
Subject(s)
Feces/analysis , Hepatitis A/diagnosis , Immunoenzyme Techniques , Animals , Antigens, Viral/analysis , Centrifugation, Density Gradient , Detergents/pharmacology , Feces/microbiology , Hepatovirus/immunology , HumansABSTRACT
Antigenic differences between type 1 poliovirus strains circulating in nature were investigated by agar diffusion precipitation reaction. Three strain-specific sera were absorbed with antigens prepared from 8 strains (Sabin's vaccine strain LSc2ab and 7 strains isolated from poliomyelitis patients or healthy persons). The results suggested the presence of at least 5 antigenic determinants in the poliovirus type 1 strains studied. Three determinants in different combinations were found in 7 strains and 2 determinants were found in 1 strain. It is assumed that antigenic differences among poliovirus strains may be due to different combinations of several antigenic determinants.
