Localization of human rhinovirus replication in the upper respiratory tract by in situ hybridization

To localize the sites and determine the extent of human rhinovirus (HRV) replication in the upper respiratory tract, biopsies of nasal and nasopharyngeal epithelia were collected from 26 HRV- or 7 sham-inoculated volunteers on days 1, 3, and 5 and on days 12, 20, or 33 after inoculation and analyzed by in situ hybridization. HRV-infected cells were detected on at least 1 day in 22 of the 23 HRV-infected subjects and in 1 of the 7 sham-inoculated subjects who developed a cold and had nasal secretions positive for a picornavirus by polymerase chain reaction. Low numbers of in situ hybridization-positive ciliated cells were present in nasal biopsies. In the nasopharynx, most HRV-infected cells were ciliated, but infected nonciliated epithelial cells were also detected. Our results indicate that HRV replicates in a very small proportion of cells in the nasal epithelium and in both ciliated and nonciliated cells in the nasopharynx of experimentally infected humans.