Greater Efficacy of Cidofovir Than of Foscarnet for the Treatment of Acyclovir-Resistant Herpes Simplex Virus Infection After Allogeneic Hematopoietic Stem Cell Transplantation

Herpes simplex virus (HSV) infection is a common problem in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Severe HSV infections can cause pneumonia, encephalitis, meningitis and other lesions, thus requiring caution. Acyclovir is the drug of choice for the prevention of HSV infection. Acyclovir resistance caused refractory HSV infection which is a severe complication after allo-HSCT. Cidofovir may be effective for acyclovir-resistant patients; however, the efficacy of systemic cidofovir administration for acyclovir-resistant patients after allo-HSCT remains unknown. We describe a 67-year-old female patient with multiple ulcers and erosions of the periocular, perioral, and oral mucosa after haploidentical allo-HSCT. Poor results were observed after the treatment of acyclovir and foscarnet. In particular, an adverse effect of low potassium and renal damage has been observed with foscarnet. Genetic testing suggested an acyclovir-resistant herpes simplex virus type 1 (HSV1) infection with T287M mutation of gene UL23. The patient's infection was cured after intravenous treatment with cidofovir. Systemic administration of cidofovir may be useful for patients with acyclovir-resistant HSV1 infection after haploidentical allo-HSCT.