Rhinovirus Transmission within Families with Children: Incidence of Symptomatic and Asymptomatic Infections

Background. Rhinoviruses are the most common cause of respiratory tract infections, but the transmission in families has not been studied using sensitive and specific molecular detection methods. Methods. Children hospitalized for any infection were screened for rhinoviruses. Eight families with a rhinovirus-positive index child and 16 families with a rhinovirus-negative index child were monitored for 3 weeks for disease symptoms, and the presence and quantity of rhinoviruses in nasal swab samples were determined by quantitative reverse transcription—polymerase chain reaction. Rhinoviruses were further identified by melting temperature and partial sequence analysis. Results. The rates of rhinovirus infection were 1.00 cases per person among the 17 siblings and 0.50 cases per person among the 14 parents of rhinovirus-positive index patients; the rates were 0.54 cases per person among the 24 siblings and 0.23 cases per person among the 30 parents of rhinovirus-negative index patients. Symptomatic infections were associated with an age of