Symptom Expression in Natural and Experimental Rhinovirus Colds

Abstract

For the past 3 decades, rhinovirus grown in cell culture and used to induce experimental infections has been assumed to produce illness comparable to natural rhinovirus illness. However, no studies have been conducted to compare the characteristics of these two illnesses. We have used two data bases, one from natural colds of proven rhinovirus etiology and one for experimental rhinovirus colds, to compare symptom occurrence. The natural cold data set contained prospectively collected data for the frequency of occurrence of symptoms for 139 insurance employees with natural rhinovirus colds. The experimental colds data base was obtained from 10 separate volunteer studies involving a total of 125 subjects who had a rhinovirus inoculation into the nose. Daily symptom frequency for the natural and experimental illnesses found that the symptoms of nasal obstruction and malaise occurred significantly more often on illness days 1–5 during experimental colds. Also, significant differences were found for days 1–4 for feverishness/fever, days 1–3 for nasal discharge, days 1–2 for sneezing, days 3–5 for sore throat, and day 1 for cough. Some of the latter symptoms occurred more frequently with experimental and some with natural infection. In general, the illnesses associated with the two types of infection were more similar than they were different.