Treatment with Brivudine in Immunocompromised Pediatric Patients with Herpes Zoster.

INTRODUCTION: Herpes zoster (HZ) is caused by endogenous reactivation of latent varicella-zoster virus (VZV) that persists in sensory ganglia after primary infection. The incidence and severity of HZ increase during immunosuppression. Especially, immunocompromised patients are at high risk of developing a cutaneous rash and suffering from delayed healing of lesions. Bromovinyl deoxyuridine (brivudine), one of the most potent oral inhibitors of VZV replication, is widely used in the therapy of HZ in adult patients, particularly in Europe. In this study, we investigated the efficacy of brivudine in immunocompromised children to provide an outpatient treatment option. METHODS: In this retrospective study, we included 64 immunocompromised pediatric patients with a median age of 14 years. Forty-seven patients received immunosuppressive therapy as part of hematopoietic stem cell transplantation and 17 patients as part of chemotherapy. Primary diagnosis was made clinically by examining the nature and the localization of the skin lesions. Laboratory confirmation was conducted based on the detection of VZV DNA in vesicle fluid and blood samples. Brivudine was administered orally at a single dose of 2 mg/kg per day. We monitored the patients' response for the full time of treatment and observed the time of full crusting of lesions, loss of crusts, and any adverse effects that occurred. RESULTS: Patients received medication for 7-21 days (median: 14 days). All children responded promptly to antiviral treatment and recovered completely from their HZ infections without complications. Crusting of lesions was reached after 3-14 days (median: 6 days). Full healing of skin lesions was ascertained within 7-21 days (median: 12 days). Overall, brivudine therapy was well tolerated. No clinical side effects during or after the treatment were observed. High compliance was achieved due to the once-daily dosing regimen. All patients were treated in an outpatient manner. CONCLUSION: Oral brivudine was a very effective and well-tolerated therapy in immunocompromised children with HZ infection. The oral administration offers the potential for outpatient treatment of HZ in these patients.

S2k guidelines for the diagnosis and treatment of herpes zoster and postherpetic neuralgia.

The present guidelines are aimed at residents and board-certified specialists in the fields of dermatology, ophthalmology, ENT, pediatrics, neurology, virology, infectious diseases, anesthesiology, general medicine and any other medical specialties involved in the management of patients with herpes zoster. They are also intended as a guide for policymakers and health insurance funds. The guidelines were developed by dermatologists, virologists, ophthalmologists, ENT physicians, neurologists, pediatricians and anesthesiologists/pain specialists using a formal consensus process (S2k). Readers are provided with an overview of the clinical and molecular diagnostic workup, including antigen detection, antibody tests and viral culture. Special diagnostic situations and complicated disease courses are discussed. The authors address general and special aspects of antiviral therapy for herpes zoster and postherpetic neuralgia. Furthermore, the guidelines provide detailed information on pain management including a schematic overview, and they conclude with a discussion of topical treatment options.

Macaca arctoides gammaherpesvirus 1 (strain herpesvirus Macaca arctoides): virus sequence, phylogeny and characterisation of virus-transformed macaque and rabbit cell lines.

Herpesvirus Macaca arctoides (HVMA) has the propensity to transform macaque lymphocytes to lymphoblastoid cells (MAL-1). Inoculation of rabbits with cell-free virus-containing supernatant resulted in the development of malignant lymphomas and allowed isolation of immortalised HVMA-transformed rabbit lymphocytes (HTRL). In this study, the HVMA genome sequence (approx. 167 kbp), its organisation, and novel aspects of virus latency are presented. Ninety-one open reading frames were identified, of which 86 were non-repetitive. HVMA was identified as a Lymphocryptovirus closely related to Epstein-Barr virus, suggesting the designation as 'Macaca arctoides gammaherpesvirus 1' (MarcGHV-1). In situ lysis gel and Southern blot hybridisation experiments revealed that the MAL-1 cell line contains episomal and linear DNA, whereas episomal DNA is predominantly present in HTRL. Integration of viral DNA into macaque and rabbit host cell genomes was demonstrated by fluorescence in situ hybridisation on chromosomal preparations. Analysis of next-generation sequencing data confirmed this finding. Approximately 400 read pairs represent the overlap between macaque and MarcGHV-1 DNA. Both, MAL-1 cells and HTRL show characteristics of a polyclonal tumour with B- and T-lymphocyte markers. Based on analysis of viral gene expression and immunohistochemistry, the persistence of MarcGHV-1 in MAL-1 cells resemble the latency type III, whereas the expression pattern observed in HTRL was more comparable with latency type II. There was no evidence of the presence of STLV-1 proviral DNA in MAL-1 and HTRL. Due to the similarity to EBV-mediated cell transformation, MarcGHV-1 expands the available in vitro models by simian and rabbit cell lines.

The impact of childhood varicella vaccination on the incidence of herpes zoster in the general population: modelling the effect of exogenous and endogenous varicella-zoster virus immunity boosting.

BACKGROUND: A controversy exists about the potential effect of childhood varicella vaccination on Herpes Zoster (HZ) incidence. Mathematical models projected temporary HZ incidence increase after vaccine introduction that was not confirmed by real-world evidence. These models assume that absence of contacts with infected children would prevent exogenous boosting of Varicella-Zoster-Virus (VZV) immunity and they do not include an endogenous VZV immunity-boosting mechanism following asymptomatic VZV reactivation. This study aims to explore the effect of various assumptions on exogenous and endogenous VZV immunity-boosting on HZ incidence in the general population after introduction of routine childhood varicella vaccination. METHODS: An age-structured dynamic transmission model was adapted and fitted to the seroprevalence of varicella in France in absence of vaccination using the empirical contact matrix. A two-dose childhood varicella vaccination schedule was introduced at 12 and 18 months. Vaccine efficacy was assumed at 65%/95% (dose 1/dose 2), and coverage at 90%/80% (dose 1/dose 2). Exogenous boosting intensity was based on assumptions regarding HZ-immunity duration, age-dependent boosting effect, and HZ reactivation rates fitted to observed HZ incidence. Endogenous boosting was the same as pre-vaccination exogenous boosting but constant over time, whilst exogenous boosting depended on the force of infection. Five scenarios were tested with different weightings of exogenous (Exo) - endogenous (Endo) boosting: 100%Exo-0%Endo, 75%Exo-25%Endo, 50%Exo-50%Endo, 25%Exo-75%Endo, 0%Exo-100%Endo. RESULTS: HZ incidence before varicella vaccination, all ages combined, was estimated at 3.96 per 1000 person-years; it decreased by 64% by year 80 post vaccine introduction, for all boosting assumptions. The 100%Exo-0%Endo boosting scenario, predicted an increase in HZ incidence for the first 21 years post vaccine introduction with a maximum increase of 3.7% (4.1/1000) at year 9. However, with 0%Exo-100%Endo boosting scenario an immediate HZ decline was projected. The maximum HZ incidence increases at 10, 3, and 2 years post vaccination were 1.8% (75%Exo-25%Endo), 0.8% (50%Exo-50%Endo) and 0.2% (25%Exo-75%Endo), respectively. CONCLUSIONS: Assuming modest levels of endogenous boosting, the increase in HZ incidence following childhood varicella vaccination was smaller and lasted for a shorter period compared with 100%Exo-0%Endo boosting assumption. Endogenous boosting mechanism could partly explain the divergence between previous HZ-incidence projections and real-world evidence.

Oil-in-water emulsion adjuvant with influenza vaccine in young children.

BACKGROUND: The efficacy of inactivated influenza vaccines is known to be poor in infants and young children. METHODS: We studied the effect of the adjuvant MF59, an oil-in-water emulsion, on the efficacy of trivalent inactivated influenza vaccine (TIV) in 4707 healthy children 6 to less than 72 months of age who had not previously been vaccinated against influenza. The children were randomly assigned to three study groups, each of which received the assigned vaccines in two doses, 28 days apart, during two consecutive influenza seasons. Two of the groups were given age-appropriate doses of TIV either with or without the MF59 adjuvant, and the third group was given control (noninfluenza) vaccines to assess their absolute and relative efficacy against influenza-like illness, as confirmed by means of polymerase-chain-reaction (PCR) assay. RESULTS: Attack rates of influenza-like illness across both influenza seasons were 0.7%, 2.8%, and 4.7% in the adjuvant, nonadjuvant, and control vaccine groups, respectively. The absolute vaccine efficacy rates against all influenza strains (94 of 110 cases were due to vaccine-matched H3N2 viruses) were 86% (95% confidence interval [CI], 74 to 93) for the MF59-adjuvant vaccine (ATIV) and 43% (95% CI, 15 to 61) for the vaccine without the adjuvant (TIV); the relative vaccine efficacy rate for ATIV versus TIV was 75% (95% CI, 55 to 87). The efficacy rates for ATIV were 79% (95% CI, 55 to 90) in children 6 to less than 36 months of age and 92% (95% CI, 77 to 97) in those 36 to less than 72 months of age, as compared with 40% (95% CI, -6 to 66) and 45% (95% CI, 6 to 68), respectively, for TIV. Antibody responses were higher with ATIV and remained so through day 181. The rates of systemic and local reactions to the influenza vaccines with and without the adjuvant were similar in the younger age group (relative risk, 1.04; 95% CI, 0.98 to 1.09), but systemic events in the older age group were more frequent after administration of ATIV (63%) than after administration of TIV (44%) or the control vaccine (50%). Serious adverse events were distributed evenly across the three vaccine groups. CONCLUSIONS: Influenza vaccine with the MF59 adjuvant is efficacious against PCR-confirmed influenza in infants and young children. (Funded by Novartis Vaccines and Diagnostics; ClinicalTrials.gov number, NCT00644059.).

Prevalence of antibodies to European porcine influenza viruses in humans living in high pig density areas of Germany.

The risk of zoonotic human infection caused by European porcine influenza virus strains was estimated in German regions with a high pig density. Sera from 622 healthy volunteers were collected between April 2009 and November 2011, mainly in Westphalia and western Lower Saxony. These included 362 subjects with occupational contact to pigs and 260 blood donors without any direct exposition to pigs. Samples were analysed by the haemagglutination inhibition (HI) assay against a panel of six swine viruses of subtypes avian-like H1N1 and human-like H3N2 as well as against human H1N1 and H3N2 viruses including the pandemic H1N1 strain of 2009. Reciprocal HI titres ≥20 were quoted as seroreactive. Compared to the control group, a significantly higher proportion of subjects with direct contact to pigs exhibited seroreactivity against porcine antigens of the avian-like H1N1 (37.0 %/7.7 %), the human-like H3N2 (59.7 %/43.1 %), the pandemic H1N1 strain of 2009 (51.7 %/26.5 %) and against a historic seasonal H3N2 strain that is closely related antigenetically to currently circulating human-like H3N2 viruses of European pigs (57.5 %/36.5 %). This trend was also observed when a reciprocal HI titre ≥40 was chosen as cut-off. Particularly, in younger subjects, the differences in seroreactivity against porcine strains between the exposed and non-exposed group were significant. The data indicate a higher risk of infection in the exposed individuals.

Seroprevalence of hepatitis E virus (HEV) in humans living in high pig density areas of Germany.

An increase in acute autochthonous hepatitis E virus (HEV) infections has been recorded in Germany. These are suspected to be zoonotically transmitted from wild boar, deer and domestic pig. The latter may represent a major reservoir for HEV. In this study, 537 sera from humans living in Westphalia and Lower Saxony, representing areas of high pig density in Germany, were tested for the presence of HEV-specific antibodies. Among them were 302 individuals with occupational, direct contact to pigs and 235 individuals without direct contact to pigs. Two commercial tests and one in-house assay were applied for the detection of HEV-specific immunoglobulin G (IgG) antibodies. Sera were also tested in an assay that detects all classes of HEV-specific antibodies. Depending on the test used, the seroprevalence ranged from 4.1 to 27.9 %. Exposition to pigs was found to be associated with a significantly higher seroprevalence in subjects with contact to pigs (13.2-32.8 %) compared with that in non-exposed humans (7.7-21.7 %). In particular, individuals younger than 40 years with occupational exposure exhibited a markedly higher HEV seroprevalence compared with non-exposed individuals of that age group. In general, HEV seroprevalence increased with age resulting in a similar prevalence level in the age group of ≥ 50 years for exposed and non-exposed individuals. Analysis of all sera by a commercial anti-HEV IgM ELISA revealed 35 positive and 25 borderline samples. However, only one positive serum could be confirmed by an IgM line assay. Selected samples from IgM and/or IgG as well as total HEV antibody-positive individuals were also tested for the presence of HEV RNA. In one of the 78 samples, the only IgM ELISA positive and IgM line assay confirmed sample, RNA of HEV genotype 3 was detected. This sequence has high similarity to HEV sequences obtained from wild boars and domestic pigs from Germany and The Netherlands. This study demonstrates that in addition to the consumption of raw or undercooked meat, direct contact to pigs has to be considered as an additional risk factor for HEV infection.

The epidemiological impact of childhood influenza vaccination using live-attenuated influenza vaccine (LAIV) in Germany: predictions of a simulation study.

BACKGROUND: Routine annual influenza vaccination is primarily recommended for all persons aged 60 and above and for people with underlying chronic conditions in Germany. Other countries have already adopted additional childhood influenza immunisation programmes. The objective of this study is to determine the potential epidemiological impact of implementing paediatric influenza vaccination using intranasally administered live-attenuated influenza vaccine (LAIV) in Germany. METHODS: A deterministic age-structured model is used to simulate the population-level impact of different vaccination strategies on the transmission dynamics of seasonal influenza in Germany. In our base-case analysis, we estimate the effects of adding a LAIV-based immunisation programme targeting children 2 to 17 years of age to the existing influenza vaccination policy. The data used in the model is based on published evidence complemented by expert opinion. RESULTS: In our model, additional vaccination of children 2 to 17 years of age with LAIV leads to the prevention of 23.9 million influenza infections and nearly 16 million symptomatic influenza cases within 10 years. This reduction in burden of disease is not restricted to children. About one third of all adult cases can indirectly be prevented by LAIV immunisation of children. CONCLUSIONS: Our results demonstrate that vaccinating children 2-17 years of age is likely associated with a significant reduction in the burden of paediatric influenza. Furthermore, annual routine childhood vaccination against seasonal influenza is expected to decrease the incidence of influenza among adults and older people due to indirect effects of herd protection. In summary, our model provides data supporting the introduction of a paediatric influenza immunisation programme in Germany.

Sequencing of 21 varicella-zoster virus genomes reveals two novel genotypes and evidence of recombination.

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.

Simvastatin treatment showed no prophylactic effect in influenza virus-infected mice.

Simvastatin, a cholesterol-lowering drug, is reported to have immunomodulatory properties that attenuated acute lung injury independent of their major lipid lowering effects. Based on these reports, simvastatin is expected to be used for influenza prophylaxis and treatment. The present study evaluated the efficacy of simvastatin against influenza A/PR/8/34 virus infection in a murine model. In a first study, simvastatin was administered orally. To achieve high plasma levels, intraperitoneal application was used in a second study. Survival, body weight loss, viral titers in lung and trachea, and histologic lung injury were measured. Surprisingly, treatment with simvastatin resulted in lower survival rates and in more distinct body mass loss in comparison to virus-infected control mice. Furthermore, the viral load in lungs and tracheas as well as histopathological lesions were not reduced by simvastatin. Overall, these results showed that simvastatin failed to protect mice against influenza virus infection.

Prevalence of herpes simplex virus type 1 glycoprotein G (gG) and gI genotypes in patients with different herpetic diseases during the last four decades.

The objective of this study was to genotype 375 clinical herpes simplex virus type 1 (HSV-1) isolates collected from the German Reference Laboratory of HSV and VZV between 1973 and 2010. The method is based on the amplification and the restriction fragment length polymorphism analysis of the glycoprotein G (gG) and gI. 45.1% of isolates were classified as genotype A, 28.5% as B, and 4.3% as C. 22.1% presented different cleavage patterns for gG and gI suggesting intergenic recombinants A/B in 7.7%, A/C in 0.5%, B/A in 9.3%, B/C in 1.9%, C/A in 1.6%, and C/B in 0.5% of isolates. Two isolates from 1982 and 2010 presented atypical gI cleavage pattern consistent with novel intragenic recombination between genotypes A and C. There were no significant differences of the prevalence of genotypes A, B as well as the recombinants A/B, B/A dependent on the age/gender of patients and the time period in which the strains were isolated. Likewise, there were no significant differences in the distribution of the genotypes A and B as etiological agents of eczema herpeticum, herpes labialis, herpes genitalis, and herpetic gingivostomatitis. The number of recombinants was not different significantly in the groups of the distinct herpetic diseases. In conclusion, the study confirms the high prevalence of recombinants in clinical HSV-1 strains. HSV-1 infections result in clinical manifestations which are independent of the gG/gI genotype and recombinants are not associated with special herpetic diseases.

Neuraminidase inhibitor susceptibility of swine influenza A viruses isolated in Germany between 1981 and 2008.

European swine influenza A viruses donated the matrix protein 2 as well as the neuraminidase (NA) gene to pandemic influenza A (H1N1) viruses that emerged in 2009. As a result, the latter became amantadine resistant and neuraminidase inhibitor (NAI) susceptible. These recent developments reflecting the close connection between influenza A virus infection chains in humans and pigs urge an antiviral surveillance within swine influenza A viruses. Here, NAI susceptibility of 204 serologically typed swine influenza A viruses of subtypes H1N1, H1N2, and H3N2 circulating in Germany between 1981 and 2008 was analyzed in chemiluminescence-based NA inhibition assays. Mean 50% inhibitory concentrations of oseltamivir and zanamivir indicate a good drug susceptibility of tested viruses. As found for human isolates, the oseltamivir and zanamivir susceptibility was subtype-specific. So, swine influenza A (H1N1) viruses were just as susceptible to oseltamivir as to zanamivir. In contrast, swine H1N2 and H3N2 influenza A viruses were more sensitive to oseltamivir than to zanamivir. Furthermore, reduction in plaque size and virus spread by both drugs was tested with selected H1N1 and H1N2 isolates in MDCK cells expressing similar amounts of α2.3- and α2.6-linked sialic acid receptors. Data obtained in cell culture-based assays for H1N1 isolates correlated with that from enzyme inhibition assays. But, H1N2 isolates that are additionally glycosylated at Asn158 and Asn163 near the receptor-binding site of hemagglutinin (HA) were resistant to both NAI in MDCK cells. Possibly, these additional HA glycosylations cause a misbalance between HA and NA function that hampers or abolishes NAI activity in cells.

Prevalence of hepatitis E virus-specific antibodies in humans with occupational exposure to pigs.

Due to the increasing number of non-travel-associated hepatitis E virus (HEV) infections observed in several industrialised countries including Germany, there is a substantial interest in the characterisation of risk factors and transmission routes relevant to autochthonous HEV infections. Autochthonous cases are believed to be the result of a zoonotic HEV transmission from pigs, wild boars and deer. Recently, a high prevalence of HEV-specific antibodies in the German domestic pig population has been demonstrated. Thus, one may assume a higher prevalence of HEV-specific antibodies in humans with occupational exposure to pigs. In this study, sera obtained from 24 slaughterers, 14 meat inspectors, 46 pig farmers and 22 veterinarians were tested for the presence of HEV-specific antibodies using a line immunoassay. For comparison, sera obtained from 116 age- and gender-matched blood donors were also included. Twenty eight per cent (28.3%; 30/106) of the swine-exposed humans and 15.5% (18/116) of the blood donors without contact to pigs exhibited IgG-antibodies determined as reactive (i.e. borderline or positive) against HEV. Thus, an increased risk of HEV infection in humans occupationally exposed to pigs and particularly for slaughterers (41.7%; 10/24) was demonstrated.

Serological response to influenza A H1N1 vaccine (Pandemrix®) and seasonal influenza vaccine 2009/2010 in renal transplant recipients and in hemodialysis patients.

In the present study, antibody response to seasonal influenza vaccination and to the adjuvanted one-shot influenza A H1N1 vaccine (Pandemrix(®)) was investigated in 57 hemodialysis (HD) patients and 48 renal transplant (RT) recipients. Specific antibodies were measured by hemagglutination inhibition (HI) test using a pandemic H1N1 strain and a seasonal H3N2 virus. HI titers of ≥1:40 were considered as protective. Hemodialysis patients showed seroprotection against pandemic H1N1 in 35.1%, against seasonal influenza in 36.8% and against both in 14.0%. In comparison, renal transplant recipients developed protective antibody titers against the pandemic H1N1 virus in 47.9%, against the seasonal H3N2 strain in 31.3% and against both in 18.8%. HD patients and renal transplant recipients younger than 60 years developed protective antibody response to the pandemic influenza H1N1 vaccine in 50.0% of the HD patients and 55.2% of the RT recipients and against seasonal influenza in 45.0/20.7% (HD/RT) of the cases. Patients aged ≥60 years showed seroprotection against pandemic influenza in 27.0/36.8% (HD/RT) and against seasonal influenza in 32.4/47.4% (HD/RT). Side effects were reported in only four patients. In hemodialysis patients and renal transplant recipients, vaccination against pandemic H1N1 and seasonal influenza is well tolerated. However, more than a half of these patients did not develop seroprotective antibody levels. Thus, new vaccines and altered vaccination regimes are likely necessary to achieve relevant antibody levels in these patient groups.

Inhibition of fatty acid synthase by amentoflavone reduces coxsackievirus B3 replication.

Coxsackievirus B3 (CVB3) is a human pathogen that causes acute and chronic infections, but an antiviral drug to treat these diseases has not yet been developed for clinical use. Several intracellular pathways are altered to assist viral transcription, RNA replication, and progeny release. Among these, fatty acid synthase (FAS) expression is increased. In order to test the potential of FAS inhibition as an anti-CVB3 strategy, several experiments were performed, including studies on the correlation of CVB3 replication and FAS expression in human Raji cells and an analysis of the time and dose dependence of the antiviral effect of FAS inhibition due to treatment with amentoflavone. The results demonstrate that CVB3 infection induces an up-regulation of FAS expression already at 1 h postinfection (p.i.). Incubation with increasing concentrations of amentoflavone inhibited CVB3 replication significantly up to 8 h p.i. In addition, suppression of p38 MAP kinase activity by treatment with SB239063 decreased FAS expression as well as viral replication. These data provide evidence that FAS inhibition via amentoflavone administration might present a target for anti-CVB3 therapy.

Does limited virucidal activity of biocides include duck hepatitis B virucidal action?

BACKGROUND: There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA). METHODS: Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining. RESULTS: The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min. CONCLUSIONS: Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.

Therapy of experimental influenza virus infection with pyrrolidine dithiocarbamate.

The search for new antiviral strategies to treat influenza A virus (IAV) infections is one major international health care activity. Hereby, the IAV-caused misuse of cellular nuclear factor kappa B (NF-κB) signaling pathways in infected cells represents one target for antiviral therapy. In the present study, pyrrolidine dithiocarbamate (PDTC), which is known as an antioxidant and as an inhibitor of IAV-induced NF-κB activation, was studied in vivo. After the antiviral activity of PDTC was confirmed in MDCK cells, mice-infected with the mouse-adapted strain of IAV A/PR/8/34 (H1N1)-were treated intraperitoneally simultaneously with PDTC (75, 150, 200 mg/kg body weight). The influence of PDTC administrations was evaluated on viral replication and inflammatory reactions in lung tissue up to 14 days postinfection (p. i.). This therapy increased survival up to 80% and reduced IAV-caused weight loss and viral replication in lung tissue in a dose-dependent manner. Protective effects were less pronounced, if the therapy started later on during an ongoing IAV infection. In addition, simultaneous PDTC treatment also limited IAV-caused infiltration of immune cells as well as local interferon-γ expression in lung tissue. These results imply that PDTC decreases IAV-caused disease in mice significantly. Therefore, the development of drugs like PDTC that interfere with NF-κB signaling may represent a modern focus of anti-IAV therapy.