Repopulation of ganciclovir-resistant cytomegalovirus by wild-type virus.

We report a patient in whom ganciclovir (GCV)-resistant cytomegalovirus (CMV) was replaced by wild-type virus after discontinuation of GCV/valganciclovir and review other similar cases. Repopulation by wild-type virus may occur soon after discontinuation and may be fostered by discontinuing GCV altogether rather than continuing it in combination with foscarnet when treating patients with GCV-resistant CMV disease.