Prevention of cytomegalovirus disease

Cytomegalovirus (CMV) is the most important pathogen in the human herpes family for immunocompromised hosts. Recognition and monitoring of CMV disease has been improved due to development of four quantitative laboratory assays for CMV: antigenemia, polymerase chain reaction for CMV DNA, branched DNA assay, and the hybrid capture assay. Prevention of posttransplant CMV disease is possible with acyclovir or ganciclovir. Preemptive therapy, which is treatment begun when a laboratory marker signifies impending tissue-invasive CMV disease, offers a cost-effective alternative to prophylaxis, but could be initiated too late in cases of fulminant CMV. Future strategies for control of CMV disease include determining the threshold quantity of CMV ('viral load') capable of producing tissue damage, developing drugs with a better therapeutic index than the presently available compounds, and insights into CMV pathogenesis especially regarding tissue tropism of the virus, which varies according to the underlying basic disease of the host.