Infections with CMV (a member of the herpes virus family) are very common and usually mild and asymptomatic. In immunocompromised patients, however, infections can be severe and sometimes fatal. Also, in utero infection of the
foetus can lead to birth defects. If the CMV IgG is positive, CMV IgM is measured to determine if the infection is current or recent.
Preparation of Patient: There is no special physical preparation for these tests.