Effect of storage on recovery of cytomegalovirus from necropsy tissue.

Cytomegalovirus (CMV) was isolated from lung tissue in 8 of 55 (14-6%) necropsies on patients who had received immunosuppressive therapy. Recovery of CMV was best (14 of 16 specimens, 87%) from fresh tissue that had been processed immediately. Storage of specimens at 4 degrees C before inoculation into cell cultures slightly reduced, to 58%, the recovery of CMV. However, conventional freezing of tissue to -- 20 degrees C for four to seven days significantly reduced the recovery of CMV, to 25% (p less than 0-001). In three of eight specimens from which virus was recovered, CMV inclusion bodies were found on tracheal smears. Sixty-five percent of the virus-negative group had measurable complement-fixing antibody in blood taken at necropsy, compared with 86% in the virus-positive group. However, there was no significant differences in antibody levels in the two groups. Our study indicates that specimens submitted for CMV isolation should be sent for virus isolation as rapidly as possible and should not be frozen. The level of antibody in a single serum taken in necropsy does not correlate well with morphological or cultural evidence of active infection.