Andreas Sauerbrei

Herpes simplex and varicella-zoster virus infections during pregnancy: current concepts of prevention, diagnosis and therapy. Part 1: Herpes simplex virus infections

Varicella during pregnancy can be associated with severe illnesses for both the mother and her neonate. Varicella pneumonia must be regarded as a medical emergency, since pregnant women are at risk of life-threatening ventilatory compromise and death. After maternal chickenpox in the first and second trimesters, congenital varicella syndrome may occur in nearly 2% of the cases. The characteristic symptoms consist of skin lesions in dermatomal distribution, neurological defects, eye diseases and skeletal anomalies. If the mother develops varicella rashes between day 4 (5) antepartum and day 2 postpartum, generalized neonatal varicella leading to death in about 20% of the cases has to be expected. Normal zoster has not been shown to be associated with maternal pneumonia, birth defects or problems in the perinatal period. On the basis of the clinical consequences of varicella-zoster virus infections during pregnancy, the present paper summarizes the currently available concepts of prevention, diagnosis and therapy.

Seroprevalence of herpes simplex virus type 1 and type 2 in selected German populations—relevance for the incidence of genital herpes

This study was carried out to determine the prevalence of antibodies to herpes simplex virus types 1 (HSV‐1) and 2 (HSV‐2) in selected German populations, such as blood donors, hospital patients, and human immunodeficiency virus (HIV)‐seropositive individuals. Serum samples collected between 1996 and 1998 were tested by enzyme immunoassays using monoclonal antibody‐selected native gG1 and gG2 as antigens and an immunoblot using type‐specific recombinant glycoproteins. Equivocal results were resolved by an “in‐house” Western blot assay. The prevalence of HSV‐1 antibodies increased steadily with age and reached high levels of ≥88% among subjects 40 years of age or older. In the sample of patients and blood donors, the HSV‐2 seroprevalence was 12.8% (95% CI = 11.9–13.8%). About 81% of the HSV‐2 seropositive subjects were coinfected with HSV‐1. When adjusted for age, there was no difference in the HSV‐2 seroprevalence between hospital patients and blood donors. The HSV‐2 seroprevalence was significantly higher among women (15%) than among men (10.5%), yielding a female : male odds ratio of 1.5 for hospital patients and of 1.67 for blood donors. Among the HIV‐infected population, 91.1% were seropositive for HSV‐1 and 47.9% for HSV‐2. HIV‐infected women have a significantly higher risk of HSV‐2 infection than men (odds ratio [OR] = 3.22; 95% confidence ratio [CI] 1.99–5.20). In conclusion, although the rate of infections with HSV‐2 is relatively low in the German population, attention should be given to the further development in adolescents, especially in view of a possible decrease of HSV‐1 seroprevalence in childhood. J. Med. Virol. 61:201–207, 2000.

Laboratory diagnosis of herpes zoster

Virological diagnosis of zoster should be rapid when effective antiviral chemotherapy is being considered. In the present study, vesicle specimens of 100 patients with zoster were analysed by detecting viral DNA using polymerase chain reaction (PCR). The findings were compared with those obtained by traditional virological and serological methods. PCR results confirmed the clinical diagnosis of zoster in 95%. Primers selected from varicella-zoster virus (VZV) gene 28 proved to be most sensitive. The sensitivity of virus culture was 20% (specificity 100%), of direct immunofluorescent VZV-specific antigen staining in vesicle samples 82% (specificity 76%), and in 48% there was a serological response to specific IgM and IgA antibodies within 4 days after the onset of rash. These findings suggest that PCR is the method of choice for rapid laboratory diagnosis of zoster.

Virological diagnosis of herpes simplex encephalitis

BACKGROUND The herpes simplex encephalitis (HSE) represents one of the most severe infectious diseases of the central nervous system. As effective antiviral drugs are available, rapid and reliable diagnosis has become important. OBJECTIVES To evaluate retrospectively the usefulness of polymerase chain reaction (PCR) as well as serological procedures for the diagnosis of HSE. STUDY DESIGN 631 cerebrospinal fluids (CSF) from patients with clinical suspicion of encephalitis were tested for type-specific herpes simplex virus (HSV) DNA using PCR. Virus-specific antibodies including their intrathecal synthesis were measured in 624 CSF and 2409 serum samples of 2711 patients suspected of having encephalitis. RESULTS Positive results were obtained by PCR in eight patients (1. 3%) for HSV-1 and in seven (1.1%) for HSV-2. Intrathecal antibody synthesis was estimated in 24 (3.8%) patients. In general, no intrathecal antibodies could be measured in patients with positive PCR results and vice versa the intrathecal immune response became positive when CSF was cleared from the HSV. Results of the antibody detection in serum specimens revealed an active HSV infection in 268 out of 2367 patients (11.3%). CONCLUSIONS The detection of HSV-DNA by PCR is the method of choice for diagnosis of HSE in the early phase of the disease. During the later stage, it has to be diagnosed by the estimation of intrathecally synthesized antibodies.

Phenotypic and genotypic characterization of acyclovir-resistant clinical isolates of herpes simplex virus

Sixteen herpes simplex virus type 1 (HSV-1) and four type 2 (HSV-2) isolates resistant to acyclovir (ACV) were characterized retrospectively for drug resistance. Phenotypic testing was performed by means of tetrazolium reduction assay and genotypic analysis was carried out by sequencing of thymidine kinase (TK) and DNA-polymerase (pol) genes. All strains were characterized as cross-resistant to penciclovir, brivudin and susceptible to cidofovir. In addition, three strains were resistant to foscarnet. Genotypic analysis revealed two to seven non-synonymous mutations in the TK gene of HSV-1 and one to seven non-synonymous mutations in the DNA pol gene of HSV-1 and 2 associated with the gene polymorphism. Seventeen strains contained at least one non-synonymous resistant-related mutation in the TK gene and three strains, which were additionally foscarnet-resistant, revealed one resistance-associated mutation in the DNA pol gene. In most strains, resistant-related mutations in TK gene represented frameshift mutations and single non-synonymous nucleotide substitutions of conserved gene regions. However, numerous amino acid changes could not be interpreted clearly as accounting for resistance. In conclusion, further studies, e.g. site-directed mutagenesis experiments are required to characterize mutations of the TK and DNA pol genes in ACV-resistant viral strains as part of viral gene polymorphism or as cause of drug resistance.

Herpes zoster by reactivated vaccine varicella zoster virus in a healthy child

Abstract. Varicella can be prevented by vaccination using the live-attenuated Oka vaccine strain of varicella zoster virus (VZV). Only mild breakthrough disease has been reported in seronegative vaccinees when exposed to the wild-type virus. The latent varicella vaccine virus has rarely caused herpes zoster in childhood and adolescence. We report a healthy 2-year-old girl who developed an impressive herpes zoster infection 16 months after vaccination, localised in three cervical dermatoma. As causative virus, VZV vaccine strain was identified by polymerase chain reaction and analysis of restriction fragment length polymorphisms of the amplified products. Conclusion: vaccine varicella zoster virus can occasionally reactivate in healthy children and present as herpes zoster. Virus characterisation is necessary to identify the strain and provide information on the incidence of occurrence.

Virucidal activity and cytotoxicity of the liposomal formulation of povidone-iodine

Two drug formulations of povidone-iodine (PVP-I)--an aqueous PVP-I solution (Betaisodona) and a liposomal PVP-I formulation--were tested for their virucidal activity and cytotoxicity in cell culture. As to the virudical activity against influenza A virus, herpes simplex virus type 1, adenovirus type 8 and human rhinovirus type 14, the liposomal formulation of PVP-I proved to be approximately as active as the aqueous one. Half maximum cytotoxic PVP-I concentrations were 0.01-0.07% for aqueous PVP-I and 0.03-0.27% for the liposomal PVP-I formulation (XTT reduction assay EZ4U). The detection of lactate dehydrogenase (LDH) release, DNA fragmentation (ELISA) and DNA strand breakage (TUNEL assay) after 24 h exposure of human embryonic lung fibroblasts to PVP-I revealed that necrosis predominates in cells treated with aqueous 0.08-0.32% PVP-I solutions, whereas apoptosis was the predominant type of cell death in cells treated with equivalent concentrations of liposomal PVP-I formulation. The favorable virucidal efficiency together with the preferred apoptotic route of cell death makes the liposomal PVP-I formulation a promising candidate for topical use in prevention and treatment of infections of the eye and the upper respiratory tract.

Distribution of varicella-zoster virus (VZV) wild-type genotypes in northern and southern Europe: evidence for high conservation of circulating genotypes.

Phylogenetic analysis of 19 complete VZV genomic sequences resolves wild-type strains into 5 genotypes (E1, E2, J, M1, and M2). Complete sequences for M3 and M4 strains are unavailable, but targeted analyses of representative strains suggest they are stable, circulating VZV genotypes. Sequence analysis of VZV isolates identified both shared and specific markers for every genotype and validated a unified VZV genotyping strategy. Despite high genotype diversity no evidence for intra-genotypic recombination was observed. Five of seven VZV genotypes were reliably discriminated using only four single nucleotide polymorphisms (SNP) present in ORF22, and the E1 and E2 genotypes were resolved using SNP located in ORF21, ORF22 or ORF50. Sequence analysis of 342 clinical varicella and zoster specimens from 18 European countries identified the following distribution of VZV genotypes: E1, 221 (65%); E2, 87 (25%); M1, 20 (6%); M2, 3 (1%); M4, 11 (3%). No M3 or J strains were observed.

Acyclovir resistance in herpes simplex encephalitis.

Herpes simplex virus type 1 is a common cause of severe sporadic encephalitis. Treatment with acyclovir is highly effective in this disease. We report the case of a 27‐year‐old, immunocompetent woman with acyclovir‐resistant herpes simplex encephalitis. Although she had not been treated before, herpes simplex virus type 1 DNA from the cerebrospinal fluid showed a non‐synonymous mutation in the thymidine kinase gene, which is likely to have caused resistance to acyclovir. Herpes simplex encephalitis resolved after treatment with foscarnet. To our knowledge, this is the first report of acyclovir‐resistant herpes simplex virus encephalitis in an immunocompetent, previously therapy‐naive adult. ANN NEUROL 2010;67:830–833

Sequencing of 21 Varicella-Zoster Virus Genomes Reveals Two Novel Genotypes and Evidence of Recombination

ABSTRACT Genotyping of 21 varicella-zoster virus (VZV) strains using a scattered single nucleotide polymorphism (SNP) method revealed ambiguous SNPs and two nontypeable isolates. For a further genetic characterization, the genomes of all strains were sequenced using the 454 technology. Almost-complete genome sequences were assembled, and most remaining gaps were closed with Sanger sequencing. Phylogenetic analysis of 42 genomes revealed five established and two novel VZV genotypes, provisionally termed VIII and IX. Genotypes VIII and IX are distinct from the previously reported provisional genotypes VI and VII as judged from the SNP pattern. The alignments showed evidence of ancient recombination events in the phylogeny of clade 4 and recent recombinations within single strains: 3/2005 (clade 1), 11 and 405/2007 (clade 3), 8 and DR (clade 4), CA123 and 413/2000 (clade 5), and strains of the novel genotypes VIII and IX. Bayesian tree inference of the thymidine kinase and the polymerase genes of the VZV clades and other varicelloviruses revealed that VZV radiation began some 110,000 years ago, which correlates with the out-of-Africa dispersal of modern humans. The split of ancestral clades 2/4 and 1/3/5/VIII/IX shows the greatest node height.