Fred D. Lakeman

Rapid detection of herpes-simplex-virus DNA in cerebrospinal fluid of patients with herpes simplex encephalitis

Herpes-simplex-virus (HSV) DNA in cerebrospinal fluid was amplified by use of the polymerase chain reaction and identified by hybridisation to a specific oligonucleotide probe. Specimens of cerebrospinal fluid (CSF) from 4 of 4 patients with herpes simplex encephalitis were positive for HSV DNA, whereas CSF specimens from 6 patients with other central-nervous-system infections were negative. This technique may expedite diagnosis of herpes simplex encephalitis.

Pharmacokinetic and Pharmacodynamic Assessment of Oral Valganciclovir in the Treatment of Symptomatic Congenital Cytomegalovirus Disease

BACKGROUNDnIntravenous ganciclovir administered for 6 weeks improves hearing outcomes in infants with symptomatic congenital cytomegalovirus (CMV) disease involving the central nervous system.nnnMETHODSnTwenty-four subjects received antiviral therapy for 6 weeks. Serial pharmacokinetic assessments were performed after administration of valganciclovir oral solution and of intravenous ganciclovir.nnnRESULTSnOn the basis of a previous pharmacokinetic study of the use of intravenous ganciclovir in this population, a target AUC12 (area under the concentration-time curve over a 12-h period) of 27 mg x h/L was defined. The median dose of oral valganciclovir administered in the present trial was 16 mg/kg, which produced a geometric mean AUC12 of 27.4 mg x h/L. The bioavailability of valganciclovir was 41.1%. Of the 18 subjects who had detectable CMV in whole blood at baseline or during therapy, 11 had <4 log viral DNA copies/mL at baseline, and 7 had > or =4 log viral DNA copies/mL at baseline; subjects who started the study with the higher viral burden experienced greater decreases in viral load but did not clear virus during the 42-day course of therapy. Neutropenia of grade 3 or 4 developed in 38% of subjects.nnnCONCLUSIONSnIn neonates with symptomatic congenital CMV disease, valganciclovir oral solution provides plasma concentrations of ganciclovir comparable to those achieved with administration of intravenous ganciclovir. The results of the present study cannot be extrapolated to extemporaneously compounded liquid formulations of valganciclovir.

Oral Acyclovir Suppression and Neurodevelopment after Neonatal Herpes

BACKGROUNDnPoor neurodevelopmental outcomes and recurrences of cutaneous lesions remain unacceptably frequent among survivors of neonatal herpes simplex virus (HSV) disease.nnnMETHODSnWe enrolled neonates with HSV disease in two parallel, identical, double-blind, placebo-controlled studies. Neonates with central nervous system (CNS) involvement were enrolled in one study, and neonates with skin, eye, and mouth involvement only were enrolled in the other. After completing a regimen of 14 to 21 days of parenteral acyclovir, the infants were randomly assigned to immediate acyclovir suppression (300 mg per square meter of body-surface area per dose orally, three times daily for 6 months) or placebo. Cutaneous recurrences were treated with open-label episodic therapy.nnnRESULTSnA total of 74 neonates were enrolled--45 with CNS involvement and 29 with skin, eye, and mouth disease. The Mental Development Index of the Bayley Scales of Infant Development (in which scores range from 50 to 150, with a mean of 100 and with higher scores indicating better neurodevelopmental outcomes) was assessed in 28 of the 45 infants with CNS involvement (62%) at 12 months of age. After adjustment for covariates, infants with CNS involvement who had been randomly assigned to acyclovir suppression had significantly higher mean Bayley mental-development scores at 12 months than did infants randomly assigned to placebo (88.24 vs. 68.12, P=0.046). Overall, there was a trend toward more neutropenia in the acyclovir group than in the placebo group (P=0.09).nnnCONCLUSIONSnInfants surviving neonatal HSV disease with CNS involvement had improved neurodevelopmental outcomes when they received suppressive therapy with oral acyclovir for 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; CASG 103 and CASG 104 ClinicalTrials.gov numbers, NCT00031460 and NCT00031447, respectively.).

Evaluation of the Range of Clinical Presentations of Herpes Simplex Encephalitis by Using Polymerase Chain Reaction Assay of Cerebrospinal Fluid Samples

Detection of DNA from herpes simplex virus in cerebrospinal fluid (CSF) samples by polymerase chain reaction (PCR) analysis has been shown to be more sensitive and specific for the diagnosis of herpes simplex encephalitis than isolation of herpes simplex virus from biopsy specimens of brain tissue. Because of the invasiveness of brain biopsy, it has been suggested that PCR analysis of CSF may reveal a wider spectrum of the disease than has been previously recognized by brain biopsy studies. In this study, PCR assay of CSF samples obtained from 29, 12, and 8 patients with focal, mild, and diffuse encephalitis, respectively, was performed. PCR assay was positive for 15 (51.7%) of 29 patients with focal encephalitis and three (25%) of 12 patients with mild encephalitis. The correlation between temporal abnormalities shown by electroencephalography, computed tomography of the brain, or cranial magnetic resonance imaging and a positive PCR assay was high. PCR analysis has revealed that atypical and less severe forms of encephalitis are caused by herpes simplex virus.

Comparison of antiviral compounds against human herpesvirus 6 and 7

Four classes of antiviral compounds were evaluated for inhibitory activity against two variants of human herpesvirus 6 (HHV-6A and -6B) and human herpesvirus 7 (HHV-7). These included: (1) a pyrophosphate analog, phosphonoformic acid (PFA); (2) beta-guanine analogs, 9-(2-hydroxyethoxymethyl)guanine (acyclovir or ACV), 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (ganciclovir or GCV) and 9-(4-hydroxy-3-hydroxy-3-hydroxymethylbutylyl)guanine (penciclovir or PCV); (3) acyclic nucleoside phosphonates, (S)-1-[(3-hydroxy-2-phosphonylmethoxy)propyl]cytosine [cidofovir or (S)-HPMPC] and its cyclic derivative (S)-cyclic-HPMPC (cHPMPC), 9-[[2-hydroxy-1-phosphonomethoxy)ethoxy]methyl]guanine (HPMEMG) and 9-[(2-phosphonylmethoxy)ethyl]-2,6-diaminopurine (PMEDAP), and the seven other related compounds; and (4) a series of benzimidazole ribonucleosides, including 2-bromo-5,6-dichloro-1-(beta-D-ribofuranosyl)benzimidazole (BDCRB). End-point inhibitory concentration (EPC) and 50% effective inhibitory concentration (EC50) values were determined by a dot-blot antigen detection method in cord blood mononuclear cells infected with HHV-6A, HHV-6B or HHV-7 at a multiplicity of infection of 0.004 CCID50/cell. (S)-HPMPC and cHPMPC had an EC50 value of approximately 0.3 microg/ml for HHV-6A, 1.2 microg/ml for HHV-6B and 3.0 microg/ml for HHV-7. These compounds were the most active of those tested against each virus. The EC50 value of GCV for HHV-6A was 0.65 microg/ml, 1.33 microg/ml for HHV-6B, and >7 microg/ml for HHV-7. The EC50 values of ACV and PCV were approximately 6-8 microg/ml for HHV-6A, 16-24 microg/ml for HHV-6B and 121-128 microg/ml for HHV-7. These drugs were the least active. The sensitivity of HHV-7 to the guanine analogs was different from HHV-6, suggesting a difference in selectivity of specific viral enzymes.

Double blind placebo-controlled trial of pleconaril in infants with enterovirus meningitis

Background. Enterovirus (EV) meningitis is common in infants and may have neurologic complications. Treatment of older children and adults with pleconaril has been associated with reduced severity and duration of symptoms. This study evaluated the pharmacokinetics, safety and efficacy of pleconaril in infants with EV meningitis. Methods. Infants ≤12 months old with suspected EV meningitis were randomized 2:1 to receive pleconaril, 5 mg/kg/dose orally three times a day or placebo for 7 days. Evaluations included pharmacokinetic determinations, safety laboratory testing, serial culture and PCR assays and clinical evaluations. Results. Of 21 evaluable subjects 20 were confirmed with EV infection (12 pleconaril, 8 placebo). Among pleconaril-treated subjects 26 of 29 peak and trough pleconaril levels exceeded the 90% inhibitory concentration for EVs. A median 3.5-fold drug accumulation occurred between Days 2 and 7. Pleconaril was well-tolerated, although twice as many adverse events occurred per subject in the pleconaril group. Serial cultures from the oropharynx, rectum and serum had low yield (≤50%) and positivity generally persisted for <4 days in both groups. Serial PCR assays of culture-negative oropharyngeal and rectal specimens had high positivity rates (generally ≥50%) persisting through Day 14. No significant differences in duration of positivity by culture or PCR, hospitalization or symptoms were detected between groups. Conclusions. The dose of pleconaril studied provided sufficient plasma levels and was well-tolerated; however, drug accumulation was evident. The low yields of serial viral cultures, relatively short and benign clinical courses and the small number of subjects enrolled precluded demonstration of efficacy. If this medication is to be prescribed in infants, surveillance for toxicity related to drug accumulation will be necessary.

Pharmacokinetics of oral valacyclovir and acyclovir in late pregnancy

OBJECTIVEnThe objective was to obtain preliminary pharmacokinetic data for acyclovir from gravid women receiving herpes simplex virus suppressive therapy with the acyclovir prodrug valacyclovir.nnnSTUDY DESIGNnIn a prospective, double-blind trial, 20 women with a history of recurrent genital herpes simplex virus infection and positive herpes simplex virus 2 serologic results were randomly assigned at 36 weeks gestation to receive oral valacyclovir (500 mg twice daily) or acyclovir (400 mg 3 times daily). Acyclovir pharmacokinetic profiles were obtained after the initial dose (36 weeks) and at steady state (38 weeks). Amniotic fluid samples were obtained during labor and simultaneous umbilical cord and maternal plasma samples were collected at delivery. Laboratory studies were performed to screen for laboratory evidence of toxicity in mothers and infants.nnnRESULTSnPeak acyclovir plasma concentrations (mean +/- standard deviation) were higher in valacyclovir recipients than in acyclovir recipients after the initial dose (3.14 +/- 0.7 microg/mL vs 0.74 +/- 0.6 microg/mL, P < .0001) and at steady state (3.03 +/- 1.0 microg/mL vs 0.94 +/- 0.7 microg/mL, P < .001). The daily area under the curve values were higher in valacyclovir recipients than acyclovir recipients after the initial dose (17.8 +/- 3.6 h x microg/mL vs 7.71 +/- 2.5 h x microg/mL, P < .001) and at steady state (19.65 +/- 6.4 h x microg/mL versus 11.0 +/- 4.5 h x microg/mL, P = .009). There was no significant difference in drug elimination half-life or in time to peak concentration between valacyclovir and acyclovir recipients at either sampling interval. Acyclovir was concentrated in the amniotic fluid; however, there was no evidence of preferential fetal drug accumulation (mean maternal/umbilical vein plasma ratios at delivery were 1.7 for valacyclovir and 1.3 for acyclovir). Valacyclovir was well tolerated, and no significant laboratory or clinical evidence of toxicity was detected.nnnCONCLUSIONnIn this phase I trial maternal valacyclovir therapy resulted in higher plasma acyclovir levels, with significantly higher peak concentrations and daily area under the curve values, than did acyclovir therapy. Additional trials are needed to further evaluate the safety and efficacy of suppressive valacyclovir therapy during late pregnancy.

Detection and diagnosis of herpes simplex virus infection in adults with acute liver failure.

Disseminated herpes simplex virus (HSV) infection may lead to acute liver failure (ALF) and the need for emergency liver transplantation (LT). The primary aim of this study was to determine the utility of HSV serological testing and HSV DNA testing by polymerase chain reaction (PCR) in the diagnosis and management of indeterminate, pregnancy‐related, and known HSV‐related ALF. Stored sera obtained on study day 1 or 2 from patients enrolled in the United States ALF Study Group with indeterminate (n = 51), pregnancy‐related (n = 12), and HSV‐related (n = 4) ALF were screened for HSV DNA by PCR and serology. While 7 of the indeterminate and pregnant patients had positive anti‐HSV immunoglobulin M, none had detectable HSV DNA. The 4 known HSV cases all had high‐titer HSV DNA on presentation (range: 3.5 to 36 × 108 copies/mL). Two HSV patients underwent LT but developed posttransplant extrahepatic HSV infection despite suppression of HSV DNA with acyclovir treatment, and one of them eventually died. The 2 other fulminant HSV patients died within 48 hours of presentation. In conclusion, serum HSV DNA indicative of occult HSV infection was not detected in 51 indeterminate and 12 pregnancy‐related ALF patients. The 4 patients with known HSV‐related ALF all had high HSV DNA levels at presentation, and despite the rapid use of antiviral therapy and emergency LT, substantial morbidity and mortality were encountered, highlighting the poor prognosis with severe disseminated HSV infection. Liver Transpl 14:1498–1504, 2008.

Oseltamivir Pharmacokinetics, Dosing, and Resistance Among Children Aged <2 Years With Influenza

BACKGROUNDnChildren <2 years of age are at high risk of influenza-related mortality and morbidity. However, the appropriate dose of oseltamivir for children <2 years of age is unknown.nnnMETHODSnThe National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group evaluated oseltamivir in infants aged <2 years in an age-de-escalation, adaptive design with a targeted systemic exposure.nnnRESULTSnFrom 2006 to 2010, 87 subjects enrolled. An oseltamivir dose of 3.0 mg/kg produced drug exposures within the target range in subjects 0-8 months of age, although there was a greater degree of variability in infants <3 months of age. In subjects 9-11 months of age, a dose of 3.5 mg/kg produced drug exposures within the target range. Six of 10 subjects aged 12-23 months receiving the Food and Drug Administration-approved unit dose for this age group (ie, 30 mg) had oseltamivir carboxylate exposures below the target range. Virus from 3 subjects developed oseltamivir resistance during antiviral treatment.nnnCONCLUSIONSnThe appropriate twice-daily oral oseltamivir dose for infants ≤8 months of age is 3.0 mg/kg, while the dose for infants 9-11 months old is 3.5 mg/kg.

The Spectrum of Genital Herpes Simplex Virus Infection in Men Attending a Sexually Transmitted Disease Clinic

BACKGROUNDnThe spectrum of genital herpes (GH) has been understudied in men, especially African American men.nnnMETHODSnConsecutive men attending a sexually transmitted diseases clinic were enrolled in a study of GH epidemiology. Consenting participants answered questionnaires detailing their sexual and social activities and underwent serological testing for herpes simplex virus types 1 and 2 (HSV-1 and -2) and collection of genital swabs for viral detection.nnnRESULTSnOf the 516 men enrolled, 465 (90%) were African American. Antibodies to HSV-1 were present in 315 (61%) of participants, and 233 (45%) had antibodies to HSV-2. Factors associated with HSV-2 infection included older age and African American race. HSV was detected in genital swabs from 52 men; 43 (82.7%) swabs were HSV-2 positive, and 9 (17.3%) were HSV-1 positive. The overall viral shedding rate among men (n = 247) with evidence of GH (HSV-1 or HSV-2 infection) was 21.1%, and the asymptomatic shedding rate in this same group was 5.2%. The sensitivities of culture for detection of HSV-1 and HSV-2 were .22 and .58, respectively, compared with that of polymerase chain reaction.nnnCONCLUSIONSnGenital HSV infections are common and largely unrecognized among this segment of the population. HSV-1 infection constitutes a nontrivial proportion of GH in these men.