Cytomegalovirus testing: antibody determinations and virus cultures with recommendations for use

Human cytomegalovirus is a ubiquitous virus with the property of becoming latent in the immunocompetent host. It can also cause devastating infections in the immunocompromised patient. Several different assays are available to detect either cytomegalovirus antibodies or cytomegalovirus itself, five of which are used at the University of Wisconsin Hospitals and Clinics and the Wisconsin State Laboratory of Hygiene. The latex agglutination (LA) test is used to detect antibody positivity in transplant donors, transplant recipients, and others. The complement fixation (CF) test is used to detect seroconversion or reactivation of infection in the CMV positive host. The immunofluorescent antibody-IgM (IFA-IgM) test is used to diagnose infection in congenitally or neonatally infected infants. The "routine" CMV culture is the "gold standard" for the detection of the cytomegalovirus in patient secretions. The shell vial assay, a rapid method of detecting virus, is most useful when contemplating therapy for active CMV infection. The advantages and limitations, as well as the timing and appropriateness of each test, are reviewed.