Monthly rate of recovery of RSV in nasopharyngeal washings from 190 cancer patients. Percentage of RSV-positive cultures for the entire population. RSV was isolated in 71 (37%) of 190 patients throughout the year, including summer (May to September). However, more cases were identified during the fall and winter seasons than spring and summer (59% versus 21%, respectively), P < .001. Twelve (44%) of 27 patients tested in July had RSV-positive cultures.