Studies of Waterborne Agents of Viral Gastroenteritis

摘要

The etiologic agent of a large outbreak of waterborne viral gastroenteritis was detected employing immune electron microscopy (IEM) and a newly developed solid phase radioimmunoassay (RIA). This agent, referred to as the Snow Mountain Agent (SMA), is 27-32 nm. in diameter, has cubic symmetry, and is morphologically similar to, but antigentically distinct from the previously described Norwalk and Hawaii agents. After an incubation period of 18 to 48 hours, the agent is shed in stools of acutely ill individuals for a period of one to five days. Employing both IEM and RIA, serum antibody rises were observed in 3/3 naturally occurring cases and in 8/9 cases of experimentally-induced illness in normal volunteers (the studies in normal volunteers had been carried out prior to the initiation of studies supported by this grant). IEM and RIA appeared to be equally sensitive for detection of antibody rises, but the RIA was more sensitive than IEM for the detection of SMA in stool specimens. Preliminary attempts to cultivate the agent in vitro were unsuccessful.