Epidemic acute infectious nonbacterial gastroenteritis at the Children's Asthma Research Institute and Hospital.

During the period from September 8 to October 2, 1970, 44 of the 120 children and 78 of 141 adults questioned at the Children's Asthma Research Institute and Hospital experienced gastroenteritis characterized by nausea, vomiting, and fever and/or chills. Diarrhea was rare in children (4.5%) and common in adults (74%). The median duration of illness for children, 18 hours, was significantly shorter than the 48 hours for adults. All viral and bacterial cultures of 30 stool specimens were negative for viruses and bacterial pathogens. A retrospective survey of 28 ill employees revealed a secondary attach rate of 46% of 76 family contacts. A bacteria-free filtrate prepared from stool swab specimens of 2 ill adults by a team at the National Institute of Allergy and Infectious Diseases was administered orally to 3 adult volunteers. One of the 3 vomited and had 4 watery diarrheal stools on the third post-inoculation day. Diarrheal stool filtrates from this person were then given orally to 8 others; 1 became ill. Although the epidemiologic features point to the respiratory route of infection, the probably successful serial transmission of disease via bacteria-free stool filtrates through 2 generations of volunteers also suggests that the "Denver agent" is a virus-sized particle that replicates in the gastrointestinal tract.