Cytomegalovirus DNAemia Requiring (Val)Ganciclovir Treatment for More Than 8 Weeks Is a Key Factor in the Development of Antiviral Drug Resistance.

Cumulative (V)GCV exposure ≥6 weeks regardless of the viral load is not associated with antiviral drug resistance. In contrast, prolonged exposure to (V)GCV during CMV replication (with a cutoff ³8 weeks) seems to be a key factor.