Treatment of an acyclovir and foscarnet-resistant herpes simplex virus infection with cidofovir in a child after an unrelated bone marrow transplant

Herpes simplex virus (HSV) causes serious problems in immuno-compromised patients such as those receiving a bone marrow transplant (BMT) for a hematological malignancy. Resistance to acyclovir (ACV) is a growing major concern. Foscarnet is a non-thymidine kinase-dependent agent, but the emergence of ACV and foscarnet-resistant HSV requires a new therapeutic approach. We describe a girl treated with cidofovir for a life-threatening ACV-resistant HSV infection after an unrelated BMT for a relapse of an acute myeloblastic leukemia (AML).