FIG. 1.

Cumulative percentage of positive hemadsorbing viruses by day detected from CRCs over 2 winter seasons. Respiratory specimens submitted for CRC during the 1997-to-1998 (white bars) and 1998-to-1999 (black bars) winter seasons were cultured for hemadsorbing viruses in three tubes of primary rhesus monkey kidney cells incubated at 33°C (two tubes) or 37°C (one tube) on a rotating drum. Cultures were examined daily for CPE and were HAD after 3 and 7 (33°C tubes; indicated by arrows) and 10 (37°C tube) days of incubation or if CPE was observed. Data are the cumulative percentage positive of hemadsorbing viruses isolated by day of detection. All isolates were detected by day 7, and all were influenza A or B.