DIAGNOSIS OF CYTOMEGALOVIRUS INFECTIONS BY SHELL VIAL ASSAY AND CONVENTIONAL CELL-CULTURE DURING ANTIVIRAL PROPHYLAXIS

A total of 3,552 specimens for conventional cytomegalovirus (CMV) cult ure and shell vial assay for CMV immediate-early antigen were obtained during a prospective randomized trial for prophylaxis of CMV disease after liver transplantation. Prophylaxis with ganciclovir for 2 weeks and then high-dose acyclovir for 2.5 months was compared with high-dos e acyclovir alone for 3 months. During the first 12 weeks after transp lantation, when the patients were on prophylaxis, there were significa ntly more clinical samples positive by the shell vial assay and negati ve by standard culture in comparison with the number of samples obtain ed from weeks 13 to 24, after prophylaxis was discontinued, that were positive by the shell vial assay and negative by standard culture. In contrast, significantly fewer samples were positive by both the shell vial assay and standard culture during the first 12 weeks compared wit h the number obtained 13 to 24 weeks after transplantation that were p ositive by both methods. Samples positive by the shell vial assay only were obtained significantly more frequently from patients with asympt omatic than symptomatic CMV infections, while samples positive by both methods were obtained significantly more often from patients with sym ptomatic CMV infection. It was concluded that antiviral prophylaxis wi th high-dose acyclovir or ganciclovir and then high-dose acyclovir and asymptomatic CMV infection are associated with a decrease in the leve l of CMV isolation by standard cell culture in comparison,vith that by the shell vial assay.