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Antigenic relatedness among the Norwalk-like agents by serum antibody rises
H P Madore1, J J Treanor, R Buja
1University of Rochester Medical Center, Infectious Disease Unit, New York 14642.
Abstract:
The Norwalk, Snow Mountain (SMA), and Hawaii agents are etiologically associated with separate outbreaks of acute viral gastroenteritis. Previous cross-challenge of volunteers, immune electron microscopy, and/or enzyme-immunoassay analysis suggested that these agents are antigenically distinct. We examined paired sera from human volunteers challenged with these agents for the presence of homologous and heterologous serum antibody titer rises to the agents. Two-way cross-reactions occurred between Hawaii agent and SMA. A one-way cross-reaction occurred between Norwalk agent and SMA, as volunteers challenged with Norwalk agent had heterologous serum antibody titer rises to SMA, but the reverse did not occur. The Norwalk and Hawaii agents had minimal cross-reaction, with only one volunteer challenged with Hawaii agents having a heterologous rise to Norwalk agent. These observations indicate varying degrees of antigenic relatedness among these agents.
Insights
Acute viral gastroenteritis outbreaks are linked to Norwalk, Snow Mountain (SMA), and Hawaii agents. Antibody testing revealed varying antigenic relatedness, with SMA cross-reacting with both Norwalk and Hawaii agents.
Area of Science:
- Virology
- Immunology
- Epidemiology
Background:
- Norwalk, Snow Mountain (SMA), and Hawaii agents cause distinct acute viral gastroenteritis outbreaks.
- Previous studies suggested these agents are antigenically distinct based on limited cross-challenge and serological data.
Purpose of the Study:
- To investigate the antigenic relatedness among Norwalk, SMA, and Hawaii agents.
- To analyze antibody responses in human volunteers experimentally infected with these gastroenteritis viruses.
Main Methods:
- Analysis of paired human volunteer sera for homologous and heterologous antibody titer rises.
- Utilizing serological assays to detect immune responses to Norwalk, SMA, and Hawaii agents.
Main Results:
- Two-way cross-reactions were observed between the Hawaii agent and SMA.
- A one-way cross-reaction occurred between the Norwalk agent and SMA.
- Minimal cross-reaction was found between the Norwalk and Hawaii agents.
Conclusions:
- The Norwalk, SMA, and Hawaii agents exhibit varying degrees of antigenic relatedness.
- Serological cross-reactivity provides insights into the antigenic relationships between these important viral gastroenteritis agents.