Problems and challenges in the diagnosis of vertical infection with human cytomegalovirus (CMV): lessons from two accidental cases.

Human cytomegalovirus (CMV) is considered as the most common cause of congenital infection in humans and the overall burden for the public health system is rather high. About 1/10 of vertically infected newborns present or develop severe signs of cytomegalic inclusion disease (CID), with the classical triad of chorioretinitis, microcephaly and cerebral calcifications. However the most symptomatic cases are detected postnatal and methods of diagnostic virology raised the questions for the gold standard in laboratory screening. The current problems in diagnosis and therapy are outlined in two different cases: An acute primary CMV infection with no clinical signs of illness in both mother and child and a secondary CMV-infection resulting in necrotizing CMV encephalitis in the fetus. Beside virus detection in whole blood samples and other fluids, newly adopted laboratory assays like the destination of CMV-IgG avidity were necessary. Furthermore a serologic screening for pregnant women should be implicated routinely. Passive IgG treatment of the mother was helpful but the ultimate goal in prevention of congenital CMV infection is to develop a vaccine, which would be administered to seronegative women.