TREATMENT OF ACYCLOVIR-RESISTANT HERPETIC ULCERATION WITH TOPICAL FOSCARNET AND ANTIVIRAL SENSITIVITY ANALYSIS

Background: Herpes simplex virus (HSV) can produce persistent mucocuta neous disease in patients with the acquired immunodeficiency syndrome (AIDS). In this case report, we evaluate the efficacy, safety and vira l resistance after topical foscarnet in severe genital ulceration due to acyclovir-resistant HSV-2. Case Report: A 45-year-old African woman was known for an HIV infection with severe immunosuppression (CD4<100 /mm3). She had received a longterm prophylaxis with acyclovir (400 mg b.i.d.) for a recurrent genital herpes. Few weeks after stopping this prophylaxis, she developed large genital ulcerations progressing despi te valacyclovir treatment (1,000 mg t.i.d.). Cultures were positive fo r HSV-2, resistance to acyclovir was shown by the plaque reduction ass ay and topical foscarnet was tried. Treatment consisted of a 20-min ap plication of topical foscarnet 2.4% twice a day. Dramatic improvement was observed with rapid antalgia, and cicatrization of the genital ulc erations was observed after 50 days. HSV could not be detected on the mucosal surface. Initially, HSV-2 was resistant to acyclovir but sensi tive to foscarnet. After 1 month of topical treatment, HSV-2 became se nsitive to acyclovir and was still sensitive to foscarnet. Finally, af ter 6 weeks of treatment, no virus could be detected by culture. Concl usion: Topical foscarnet (2.4%) is a convenient treatment for chronic genital herpes. Resistance to acyclovir disappears few weeks after sto pping this drug and sensitivity to foscarnet persists during the 50 da ys of treatment.