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Non-A, non-B hepatitis in experimentally infected chimpanzees with the NIH strains F and H
Abstract:
The NIH strains F and H of non-A, non-B hepatitis were studied by transmission to chimpanzees. They developed biochemical and ultrastructural evidences of non-A, non-B hepatitis. Chimpanzee's plasma containing the strain F was passaged further three times in the present study, and the results were identical to the original report made by SHIMIZU et al. In contrast to the original report, however, the prototype strain H inoculum or human plasma supposedly containing only the strain H, induced both SHIMIZU's cytoplasmic and nuclear changes in one chimpanzee. This result may pour further oil on the flame of recent controversy regarding the sequestration of the strains H and F, but we believe at present that the strains H and F are separate infectious agents. This is based on the fact that the strain F never induced SHIMIZU's nuclear changes, and our detection of an additional infectious agent of non-A, non-B hepatitis identical to the NIH strain H. We suspect the NIH strain H inoculum provided to us was contaminated by the strain F. The conclusion of controversy regarding the strain H should await for further studies including a further cross challenge study between the strain H and the strain F. Ultrastructural changes of the chimpanzee's liver associated with non-A, non-B hepatitis are described.
Insights
NIH strains F and H of non-A, non-B hepatitis were transmitted to chimpanzees, showing distinct viral characteristics. Further studies are needed to resolve controversy regarding these separate infectious agents.
Area of Science:
- Hepatology
- Virology
- Infectious Diseases
Background:
- Non-A, non-B hepatitis remains a significant diagnostic challenge.
- Distinguishing between different viral strains is crucial for understanding disease pathogenesis.
- Previous studies by SHIMIZU et al. identified distinct cellular changes associated with NIH strains F and H.
Purpose of the Study:
- To investigate the distinct characteristics of NIH strains F and H of non-A, non-B hepatitis.
- To assess the infectivity and pathological changes induced by these strains in chimpanzees.
- To contribute to the ongoing controversy regarding the distinctness of strains H and F.
Main Methods:
- Transmission of NIH strains F and H to chimpanzees.
- Monitoring biochemical and ultrastructural evidence of hepatitis in infected chimpanzees.
- Serial passaging of strain F and analysis of strain H inoculum.
Main Results:
- Strain F transmission consistently induced non-A, non-B hepatitis with biochemical and ultrastructural changes.
- Strain H inoculum induced both cytoplasmic and nuclear changes in one chimpanzee, differing from previous reports.
- Strain F did not induce nuclear changes, supporting its distinction from strain H.
Conclusions:
- NIH strains F and H are likely separate infectious agents based on observed pathological differences.
- The NIH strain H inoculum may have been contaminated with strain F.
- Further cross-challenge studies are required to definitively resolve the controversy surrounding strains H and F.