New advances in the diagnosis of congenital cytomegalovirus infection

With the advances in anticytomegalovirus (anti-CMV) serology, the new recom binant IgM tests seem likely to become the screening tests for pregnant wom en whose prepregnancy serological status for CMV is unknown. When a woman i s found to be IgM-positive, further diagnostic evaluation focused on determ ining whether this is due to a primary infection should be carried out. Mat ernal primary infections that were difficult to determine until a few years ago unless documented by seroconversion can now be readily diagnosed from the presence of low-avidity anti-CMV antibody which persists for approximat ely 20 weeks after primary infection. In primarily infected mothers prenata l diagnosis can be performed between 21 and 23 weeks of gestation, and the amniotic fluid (AF) represents the pathological material of choice to deter mine intrauterine virus transmission. In AF, the virus can be detected by c ulture and/or PCR. Both procedures differentiate uninfected from infected f etuses, but cannot predict fetal outcome. The determination of the viral lo ad in AF carried out by quantitative PCR is more promising and could repres ent an important starting point for preemptive fetal therapy. Copyright (C) 2000 S. Karger AG, Basel.