INTRODUCTION: In children with cancer, varicella can be complicated by visceral dissemination with a risk of fatal outcome, especially in children with acute lymphoblastic leukaemia (ALL). Immunoprophylaxis and antiviral therapy have reduced the mortality, but the morbidity remains significant and is explored here in a cohort of children with ALL. MATERIAL AND METHODS: Among 67 children diagnosed with ALL during 1992-2007, 22 were seronegative for varicella-zoster virus (VZV) at the time of diagnosis. Patient records were reviewed to describe varicella exposures, eruptions and vaccinations during chemotherapy (24-30 months) and the following six months of immune recovery. RESULTS: Fifteen exposures were recognised in eight children and were managed with oral acyclovir prophylaxis; three resulted in clinical infection. Adoption of brief prophylaxis in the second week of incubation has not - so far - increased the infection rate (one in six versus two in nine). A further six varicella cases occurred without recognised exposure. All nine eruptions (in eight children) were uncomplicated but entailed hospitalisation days for intravenous therapy with acyclovir and loss of chemotherapy days. Seven children were VZV-vaccinated during maintenance chemotherapy; none developed varicella or zoster later in the course. CONCLUSION: Despite protective isolation and prophylactic treatment, seronegative children with ALL have a high risk of varicella during or shortly after chemotherapy. We recommend that susceptible siblings should be vaccinated at the time of diagnosis and the child should receive vaccination once oral maintenance chemotherapy has been initiated.

Cytomegalovirus is a major viral pathogen in patients who undergo renal transplantation, and cytomegalovirus disease is difficult to treat. We therefore conducted a randomized, placebo-controlled, double-blind trial of acyclovir for the prevention of cytomegalovirus disease in recipients of renal allografts from cadavers. Acyclovir was given orally in doses of 800 to 3200 mg per day, according to the patients' estimated level of renal function. Patients took the first dose of either acyclovir or placebo six hours before transplantation and continued to take the assigned medication for 12 weeks. Of 118 patients enrolled in the study, 104 completed at least 30 days on the study medication and were included in our analysis of the results. During the first year after transplantation, 4 of 53 patients (7.5 percent) in the acyclovir group had symptomatic cytomegalovirus disease, as compared with 15 of 51 (29 percent) in the placebo group (P = 0.002). There was a single case of cytomegalovirus pneumonia in the acyclovir group, as compared with nine in the placebo group. The greatest prophylactic benefit of acyclovir was observed among seronegative patients who had received a kidney from a seropositive donor; only one of six such patients in the acyclovir group had cytomegalovirus disease, as compared with all seven in the placebo group. Acyclovir decreased the incidence of documented cytomegalovirus infection (with or without symptomatic disease) to 36 percent from 61 percent among the patients who received the placebo (P = 0.011). Among the patients who received acyclovir, the rates of recovery of virus from the blood and urine were significantly reduced, but the rate of viral shedding from the pharynx was not significantly different from that in the placebo group. There were no differences between the groups in the frequency of adverse events or in the rate of survival of either grafts or patients. We conclude that the oral administration of acyclovir, beginning before the transplantation of a renal allograft from a cadaver, reduces the rate of cytomegalovirus infection and disease without affecting the survival rate of either grafts or patients.

We randomly assigned 208 patients who underwent brain biopsy for presumptive herpes simplex encephalitis to receive either vidarabine (15 mg per kilogram of body weight per day) or acyclovir (30 mg per kilogram per day) for 10 days. Sixty-nine patients (33 percent) had biopsy-proved disease; 37 received vidarabine, and 32 acyclovir. The mortality in the vidarabine recipients was 54 percent, as compared with 28 percent in the acyclovir recipients (P = 0.008). Six-month mortality varied according to the Glasgow coma score at the onset of therapy. For scores of greater than 10, 7 to 10, and less than or equal to 6, mortality was 42, 46, and 67 percent in the patients treated with vidarabine, as compared with 0, 25, and 25 percent in those treated with acyclovir. A six-month morbidity assessment using an adapted scoring system revealed that 5 of 37 patients receiving vidarabine (14 percent) as compared with 12 of 32 receiving acyclovir (38 percent) were functioning normally (P = 0.021). Eight vidarabine-treated patients (22 percent) and three acyclovir-treated patients (9 percent) had moderate debility. Patients under 30 years of age and with a Glasgow coma score above 10 had the best outcome with acyclovir treatment. We conclude that acyclovir is currently the treatment of choice for biopsy-proved herpes simplex encephalitis.

Reactivation of herpes simplex virus type 2 (HSV-2) occurs intermittently as perceived clinically and by viral culture. We performed a series of studies to evaluate the frequency and pattern of HSV-2 reactivation using both viral isolation and HSV PCR assay. Daily samples of genital secretions were obtained from 27 HSV-2 seropositive women; a subset of subjects obtained samples while receiving oral acyclovir 400 mg PO twice a day. HSV DNA was detected in genital swab specimens on 28% of 1,410 d compared with 8.1% of days by viral isolation. 11 of 20 women had HSV DNA detected on > 20% of days, 4 on > 50%, and 2 on > 75% of days; in contrast, none of the women shed on > 21% of days by viral isolation. The daily administration of oral acyclovir promptly reduced the frequency of HSV DNA detection by a median of 80%. Within 3-4 d of discontinuing daily acyclovir, HSV DNA again appeared in the genital area. HSV-2 shedding in the genital mucosa occurs much more frequently than previously appreciated. This frequent reactivation likely plays a role in the epidemic spread of genital herpes worldwide.

Despite current approaches to prophylaxis, cytomegalovirus (CMV) continues to be a common cause of infection and disease in solid-organ-transplant patients. Thus, we conducted a controlled trial comparing long-term administration of ganciclovir with high-dose acyclovir for prevention of CMV infection and disease in liver transplant recipients. At the time of transplant, patients were randomised to receive either ganciclovir (6 mg/kg body weight per day intravenously from postoperative day 1 to day 30, then 6 mg/kg per day Monday through Friday until day 100) or acyclovir (10 mg/kg intravenously every 8 h from postoperative day 1 to day of discharge, then 800 mg orally four times a day until day 100). Patients were followed for development of CMV infection, CMV disease, and drug-related toxicity by frequent cultures, serological tests, laboratory measurements, and tissue biopsies. During the first 120 days after transplant, CMV infection occurred in 48 of 126 (38%) acyclovir patients but in only 6 of 124 (5%) ganciclovir patients (p < 0.0001). Similarly, symptomatic CMV disease developed in 12 of 126 (10%) acyclovir patients but in only 1 of 124 (0.8%) ganciclovir patients (p = 0.002). Ganciclovir reduced the incidence of CMV infection in both CMV antibody positive (37 vs 4%, p = 0.001) and negative patients (42 vs 11%, p = 0.06). In a multivariate analysis of donor-recipient CMV antibody status and other risk factors, prophylactic ganciclovir was the most significant factor protecting against CMV infection (p < 0.0001) and disease (p = 0.001). Ganciclovir and acyclovir were generally well-tolerated. Incidences of leukopenia, thrombocytopenia, renal failure, and other adverse events were similar in the two groups. CMV can be eliminated almost completely as a significant pathogen in liver transplant recipients by the long-term administration of prophylactic ganciclovir. In addition, the treatment is safe.

We studied 35 otherwise healthy adults with frequently recurring genital herpes (greater than or equal to 1 episode per month), in a double-blind trial comparing oral acyclovir with placebo capsules for suppression of recurrent infection. The patients were treated for 125 days unless herpes recurred. Among 32 evaluable patients, there were significantly fewer recurrences during acyclovir treatment (4 of 16) than during placebo treatment (16 of 16, P less than 0.001). The mean duration of therapy was significantly longer for patients receiving acyclovir than for those receiving placebo (114.9 vs. 24.8 days, P less than 0.001). Of 19 patients who had recurrences in the blind trial, only 2 had recurrences when given acyclovir in a second, open-study phase. All patients had recurrences after completing acyclovir treatment. The therapy was well tolerated, with minimal gastrointestinal upset and one hypersensitivity reaction. Studies of the viral isolates demonstrated that lesions developing in patients receiving acyclovir contained drug-resistant virus. Later recurrences in these patients were associated with drug-sensitive virus. We conclude that oral acyclovir suppresses genital herpes in patients with frequent recurrences, but the potential for problems with drug resistance and the long-term safety need to be more fully explored.

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). Our aim was to study the prophylactic effect of high-dose intravenous acyclovir given around the time of BMT followed by oral acyclovir on CMV infection and survival. 310 BMT recipients at risk of developing CMV infection were randomised to one of three regimens in a double-blind and double-dummy design: intravenous acylclovir (500 mg/m2, three times a day) for 1 month followed by oral acyclovir (800 mg four times a day for a further 6 months)(intravenous/oral group); intravenous acyclovir followed by oral placebo (intermediate group); or low-dose oral acyclovir (200 or 400 mg, four times a day) followed by placebo ("controls"). Analysis was by intention-to-treat. Intravenous acyclovir significantly reduced the probability of and delayed the onset of CMV infection. There was no further reduction in infection risk with the addition of long-term oral acyclovir. Time to CMV viraemia was delayed in the intravenous/oral acyclovir group compared with controls. Extending the prophylaxis with oral acyclovir significantly improved survival: 79 of 105 recipients were still alive at 7 months compared with 60 of 102 controls (p = 0.012). Although the intravenous/oral acyclovir group did significantly better than controls in terms of survival, the difference between the intravenous/oral acyclovir group and the intermediate group was of borderline statistical significance (p = 0.054). Adverse events that were possibly treatment related were similar in all three groups. The most commonly reported events were nausea, vomiting, elevated creatinine, and renal failure. High-dose intravenous followed by oral acyclovir improved survival and was of benefit in prophylaxis against the effects of CMV after BMT. Interpretation of CMV infection was made difficult because an intermediate treatment (intravenous acyclovir followed by oral placebo) was as effective as high-dose intravenous/oral acyclovir.

Oral acyclovir, 800 mg five times per day for seven days, was compared with placebo in a randomized, double-blind trial conducted at three centers in the United Kingdom. The study group consisted of 364 elderly immunocompetent patients with herpes zoster who were entered within 72 hours of the onset of rash. Acyclovir significantly reduced the times to last new lesion formation (p less than 0.01), loss of vesicles (p less than 0.01), and full crusting (p = 0.03). No significant hastening of rash healing was seen in those who started therapy later than 48 hours after the onset of rash. There was also a significant reduction pain during treatment with acyclovir (p = 0.02). Acyclovir produced no effects on the frequency or severity of post-herpetic neuralgia. No clinically important adverse effects of acyclovir were reported.

Forty-one patients with herpes zoster were treated with acyclovir or placebo at a dosage of 400 mg five times a day by mouth for five days in a double-blind randomized domiciliary study. Acyclovir was shown to reduce the days of new lesion formation within the effected dermatome after day 0 (P = 0.049). No other statistical difference was demonstrated between the two groups although the trends for new lesion formation outside the dermatome, full crusting, involution and diminution of acute pain all favoured acyclovir.

Zoster is a common disease that may be associated with severe and protracted pain. Antiviral therapy with acyclovir intravenously has been shown to modify the course of the disease and reduce pain during the acute phase. The results of two studies using doses of 400 mg and 800 mg of acyclovir orally are outlined. The data suggest a significant benefit of the higher dose treatment on the course of the illness and the pain.

OBJECTIVE: To assess the efficacy of high-dose oral acyclovir therapy compared with preemptive, short-course ganciclovir therapy (administered only if cytomegalovirus [CMV] shedding occurred) to prevent CMV disease in liver transplant recipients. DESIGN: A randomized controlled trial. SETTING: Liver transplant center at a university-affiliated Veterans Affairs Medical Center. PATIENTS: 47 consecutive patients having liver transplantation. INTERVENTION: Patients were stratified by their CMV antibody status and the CMV antibody status of the donor and were randomly assigned to one of two treatment groups. Surveillance cultures for CMV (buffy coat and urine) were done every 2 to 4 weeks for 24 weeks in all patients. One group received high-dose oral acyclovir (800 mg four times daily). The experimental group received no acyclovir, but if surveillance cultures were positive, ganciclovir (5 mg/kg intravenously twice daily) was administered for 7 days. MEASUREMENTS: Cytomegalovirus shedding and CMV disease were measured in the two groups. RESULTS: Cytomegalovirus shedding before the onset of CMV disease occurred in 25%(6 of 24) of patients in the acyclovir group compared with 22%(5 of 23) in the experimental group. Cytomegalovirus disease developed in 29%(7 of 24) of the acyclovir group and in 4%(1 of 23) of the experimental group (P < 0.05). No hematologic toxicity occurred with ganciclovir. CONCLUSION: Oral acyclovir is ineffective prophylaxis against CMV in liver transplant recipients. Preemptive, short-course ganciclovir therapy in patients with CMV shedding was well tolerated and provided effective prophylaxis against subsequent CMV disease; this protocol targets the patients at risk for CMV disease and minimizes toxicity and expense.