Varicella exposure in a neonatal medical centre: successful prophylaxis with oral acyclovir.

In December 2000, a female infant hospitalized in our Neonatal Care Centre was infected with varicella by her mother. Although prophylactic intravenous acyclovir was administered at a dose of 15 mg/kg daily, she later developed varicella during her hospital stay. We therefore initiated control procedures to prevent further hospital-acquired infections. Oral acyclovir (40 mg/kg daily divided into four doses) was administered prophylactically to six preterm infants in contact with the varicella patient. None of six preterm infants subsequently developed clinical varicella or had any adverse effects associated with acyclovir administration. It is suggested that prophylactic administration of oral acyclovir (40 mg/kg daily) might prevent hospital-acquired varicella-zoster virus (VZV) infections, and that oral acyclovir may be an option for VZV prophylaxis in situations where VZV immunoglobulin is not available.