Inoculation of Human Volunteers with Parainfluenza Virus Type 3

Abstract

In an attempt to see whether parainfluenza virus type 3 would produce illness in adults, 28 adult volunteer subjects were inoculated with either the virus or a sterile salt solution. Twelve of the 17 volunteers inoculated with the virus, and none of the 11 who received the placebo inoculum, developed laboratory evidence of infection with parainfluenza 3 virus. Nine of the virus-inoculated volunteers and only 1 of the 11 in the contratested group developed an acute respiratory illness. However, 3 of the 9 virus-inoculated subjects who became ill failed to demonstrate laboratory evidence of infection with parainfluenza 3. The afebrile, "coldlike" illness observed in the 6 infected volunteers was characterized by mucoserous nasal discharge, nasal obstruction, sneezing, dry cough, and erythematous nasal and pharyngeal mucous membranes. The mean incubation period was 2.2 days.