Surveillance network for herpes simplex virus resistance to antiviral drugs: 3-year follow-up

Herpes simplex virus (HSV) infections are very common in the general population and among immunocompromised patients. Acyclovir (ACV) is an effective treatment which is widely used. We deemed it essential to conduct a wide and coordinated survey of the emergence of ACV-resistant HSV strains. We have formed a network of 15 virology laboratories which have isolated and identified, between May 1999 and April 2002, HSV type 1 (HSV-1) and HSV-2 strains among hospitalized subjects. The sensitivity of each isolate to ACV was evaluated by a colorimetric test (C. Danve, F. Morfin, D. Thouvenot, and M. Aymard, J. Virol. Methods 105:207-217, 2002). During this study, 3900 isolated strains among 3357 patients were collected; 55% of the patients were immunocompetent. Only six immunocompetent patients excreted ACV-resistant HSV strains (0.32%), including one female patient not treated with ACV who was infected primary by an ACV-resistant strain. Among the 54 immunocompromised patients from whom ACV-resistant HSV strains were isolated (3.5%), the bone marrow transplantation patients showed the highest prevalence of resistance (10.9%), whereas among patients infected by human immunodeficiency virus, the prevalence was 4.2%. In 38% of the cases, the patients who excreted the ACV-resistant strains were treated with foscarnet (PFA), and 61% of them developed resistance to PFA. The collection of a large number of isolates enabled an evaluation of the prevalence of resistance of HSV strains to antiviral drugs to be made. This prevalence has remained stable over the last 10 years, as much among immunocompetent patients as among immunocompromised patients.

[What's new in vaccines against herpes simplex infections?]

Herpes simplex viruses (HSV) can cause a variety of infections, including genital herpes. Despite effective antiviral therapy HSV infections remain a public health problem. Vaccines offer the possibility for controlling the spread and limiting HSV disease, two strategies for herpes vaccination: prophylactic immunization or therapeutic immunization. The article discusses the results of different studies, in particular, concerning recombinant vaccines, DISC vaccines and DNA vaccines.

Native valve endocarditis due to Enterococcus hirae

Enterococcus hirae is a rare isolate in clinical specimens. We describe a case of native aortic-valve endocarditis that was caused by Enterococcus hirae in a 72-year-old man. This is the first reported case of endocarditis due to this organism.

Seroprevalence of HSV-1 and HSV-2 infection in the general French population

BACKGROUND

In spite of the large prevalence and growing incidence of herpes simplex infection (HSV-1 and HSV-2), relatively few large serological surveys are available worldwide and it is still difficult compare frequencies of HSV contaminations in various countries. We present the results of HERPIMAX, the first epidemiological inquiry on HSV prevalence in the general French population.

METHODS

Of a cohort of 12,735 presumed healthy adult volunteers included in the prospective study SU.VI.MAX, designed to assess the relation between nutritional supplementations and degenerative diseases, HERPIMAX randomly selected 4412 subjects (females 66.5%, males 33.5%). All serum samples were assessed for HSV-1 and HSV-2 IgG antibodies with a HSV type specific, enzyme immunosorbent assay (EIA). Equivocal result were retested with another HSV type specific immunoblot assay combined with a type common HSV IgG EIA in order to give a definitive interpretation.

RESULTS

The mean seroprevalence was 67% for HSV-1 and 17.2% for HSV-2. For HSV-2 the seroprevalence was higher in females (17.9%) compared with males (13.7%) (p<0.001). For both HSV types, there was no significant difference in prevalence as regards age distribution in males and females, whereas prevalence increased significantly with age in females for HSV-1. Univariate analysis showed a significant association between HSV-1 prevalence and education level in males and females (p<0.001) and between HSV-2 prevalence and marital status in both sexes (p<0.001). There were geographical disparities, with a higher HSV-2 prevalence in the south of France as well as in Paris.

CONCLUSION

These results confirm a high prevalence of HSV infection in France. They are also in agreement with previous results of other survey carried out in other developed countries as regards higher prevalence of HSV-2 infection in women, the stability of seroprevalence for both HSV types after 35 years of age in females and 45 years of age in males.

[Natural history of HSV1 and HSV2 infection. Asymptomatic viral excretion. Mother-infant transmission. Indirect transmission]

Recurrent asymptomatic viral shedding accounts for most of the oral, sexual and neonatal transmissions of herpes simplex infections (HSV). In immunocompetent individuals asymptomatic shedding, as determined by culture, occurs during 2-8p.100 of days, and more for persons with HIV infection or if measured by PCR. Antiviral therapy dramatically decrease but does not eliminate asymptomatic shedding. The main risk of HSV transmission to the neonate is during vaginal delivery from infected asymptomatic mothers who acquire HSV genital infection late in pregnancy. Because the survival of HSV out of the oral-genital secretions is weak, indirect and/or nosocomial transmisions of HSV are very rare and should be controlled by common-sense precautions. The prevention of the acquisition of genital or neonatal HSV infection is a challenge because it is based on the understanding and the control of asymptomatic shedding.

A prospective study of Epstein-Barr virus load in 85 hematopoietic stem cell transplants

EBV viral load (EBV-VL) in PBMC was prospectively determined by semi-quantitative PCR in 85 stem cell transplants (40 genoidentical, 45 non-genoidentical) in order to characterize the kinetics of EBV-VL and to assess the ability of this measure to predict the development of EBV-induced lymphoproliferative disease (EBV-LPD). PCR was performed prior to and after transplantation. An EBV-VL >300 copies/microg DNA was chosen as the threshold for risk of developing an EBV-LPD. Two hundred and fifty-eight EBV-VL measures were evaluable. Five patients (5.9%) developed an EBV-LPD. All had an elevated EBV DNA peak level before EBV-LPD. Fifteen out of 80 recipients (18.7%) without EBV-LPD had EBV levels over 300 copies/microg DNA at least once during the follow-up. Overall, the manifestation of at least one EBV-VL over 300 copies/microg DNA during the entire follow-up demonstrated a sensitivity, specificity, positive and negative predictive value for the diagnosis of EBV-LPD of 100%, 81%, 25% and 100%, respectively. In patients without EBV-LPD, HLA incompatibility, grade > or = II acute GVHD and use of an unmanipulated graft were significantly associated with an EBV-VL >300 copies/microg DNA. This strategy appears sensitive for the diagnosis of EBV-LPD but its positive predictive value has to be improved in order to guide pre-emptive therapy.

Lack of seroconversion in a health care worker after polymerase chain reaction-documented acute hepatitis C resulting from a needlestick injury

We present a case of documented acute hepatitis C that occurred in a health care worker who sustained a needlestick injury while caring for an individual who was infected with both hepatitis C virus (HCV) and human immunodeficiency virus (HIV). According to the findings of third-generation serological assays performed during a follow-up of >1 year, the health care worker, who was treated with interferon-alpha (during weeks 2-6) and ribavirin (during weeks 5-9), did not develop antibodies against HCV, in spite of documentation of an HCV-specific T cell response.

Functional determinants of the Epstein-Barr virus protease

Herpesvirus proteases are essential for the production of progeny virus. They cleave the assembly protein that fills the immature capsid in order to make place for the viral DNA. The recombinant protease of the human gamma-herpesvirus Epstein-Barr virus (EBV) was expressed in Escherichia coli and purified. Circular dichroism indicated that the protein was properly folded with a secondary structure content similar to that of other herpesvirus proteases. Gel filtration and sedimentation analysis indicated a fast monomer-dimer equilibrium of the protease with a K(d) of about 60 microM. This value was not influenced by glycerol but was lowered to 1.7 microM in the presence of 0.5 M sodium citrate. We also developed an HPLC-based enzymatic assay using a 20 amino acid residue synthetic peptide substrate derived from one of the viral target sequences for the protease. We found that conditions that stabilised the dimer also led to a higher enzymatic activity. Through sequential deletion of amino acid residues from either side of the cleavage site, the minimal peptide substrate for the protease was determined as P5-P2'. This minimal sequence is shorter than that for other herpesvirus proteases. The implications of our findings are discussed with reference to the viral life-cycle. These results are the first ever published on the EBV protease and represent a first step towards the development of protease inhibitors.

Change in transaminases in hepatitis C virus- and HIV-coinfected patients after highly active antiretroviral therapy: differences between complete and partial virologic responders?

Patients with HIV and hepatitis C virus (HCV) coinfection have more severe hepatitis-related disease than do patients with HCV infection alone. Highly active antiretroviral therapy (HAART) with protease inhibitor appears to restore pathogen-specific immune responses, especially in patients with persistent undetectable HIV viral load. To evaluate the potent impact of immune restoration induced by HAART on the course of HCV-related disease, HCV viremia and levels of transaminases were compared between two groups of patients: 10 HIV/HCV-coinfected patients with persistently undetectable HIV viremia (group A) and 12 HIV/HCV-coinfected patients with persistent detectable HIV viremia. No difference was detected in HCV viral load in either group. An increase in transaminases was found only in patients with persistent undetectable HIV viral load, which was correlated with the increase in CD8+ T cells. This may suggest that the restoration of CD8+ T cell cytotoxicity could lead to an enhancement of hepatitis C-related disease in HCV/HIV-coinfected patients receiving HAART.

Do pathogenic neisseriae need several ways to modify the host cell cytoskeleton?

Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens which have to interact with mucosa and/or cellular barriers for their life cycle. Even though they both give rise to dramatically different diseases, most of the mechanisms mediating cellular interactions are common to N. meningitidis and N. gonorrhoeae. This suggests that bacterial cell interactions may be essential not only for pathogenesis but also for other aspects of the bacterial life cycle that are common to both N. meningitidis and N. gonorrhoeae. Opacity proteins and pili are two major components identified as transducing signals to host cells, thus leading to cytoskeleton modifications. This manuscript will review the recent developments concerning the mechanisms mediating cellular interactions of pathogenic Neisseria and will tentatively put them into the perspective of pathogenesis and bacterial life cycle.

[Malignant non-Hodgkins B lymphoma related to Epstein-Barr virus and chronic natural killer lymphocytosis in a immunocompromised patient]

INTRODUCTION

Immunocompromised patients are at high risk of Epstein-Barr virus (EBV)-related lymphoproliferative disorders. The lymphoproliferation affects B, T, and natural killer (NK) cells.

EXEGESIS

We report the case of a woman suffering from systemic lupus erythematous. She developed an opportunistic pneumonia while immunodepressed during long-term corticotherapy aimed at curing her auto-immune disease. Chronic lymphocytosis was also diagnosed at this time. Several months later, non-Hodgkin's lymphoma was diagnosed. Genomic amplification of the Epstein-Barr virus in the patient's blood and positive EBV latent membrane protein 1 on the lymph nodes provided evidence for a strong correlation between EBV reactivation and lymphoma.

CONCLUSION

Two distinct lymphoid diseases occurred during the immunosuppressive therapy for the auto-immune disease. PCR monitoring of Epstein-Barr virus allows for early screening of lymphoproliferative disorders in immunocompromised patients, leading to earlier and more efficient treatment.

[1977 mortality rate in HIV-infected patients presenting with hepatitis C cirrhosis. Results of the GERMIVC multicenter survey conducted in French departments of internal medicine or infectious disease]

PURPOSE

Hepatitis C (HCV) has a high prevalence (10-30%) among human immunodeficiency virus (HIV)-infected patients. However, little information is available regarding the impact of hepatitis C on survival. The objective of our study was to determine the incidence of hepatitis C-related deaths in HIV-HCV co-infected patients.

METHODS

The study was a retrospective (1-year), multicenter cohort survey conducted in 63 departments of either internal medicine or infectious diseases in France. It included 26,497 HIV-infected patients, of whom 4,465 (16.8%) presented coinfection due to the hepatitis C virus. The following parameters were studied for the year 1997: total number of deaths, number of deaths related to either AIDS, cirrhosis, hepatocellular carcinoma, or other causes.

RESULTS

Among the 26,497 patients, 543 deaths (incidence: 2%) were observed in 1997; 543 deaths were due to AIDS (incidence: 1.7%), 36 to cirrhosis and/or hepatocellular carcinoma (incidence: 0.13%), and 48 (incidence: 0.18%) to another cause. In the subgroup including 4,465 HIV-HCV-coinfected patients, 29 deaths (incidence: 0.64%) were due to either HCV-related cirrhosis or hepatocellular carcinoma. These results were compared with those of a previous similar survey conducted in 1995, before the era of highly active antiretroviral therapy. The only significant difference is the dramatic regression of deaths due to AIDS.

CONCLUSION

The impact of hepatitis C virus on the mortality among HIV-infected patients whose follow-up took place in departments of either internal medicine or infectious diseases in France was very low in 1997. The expected increase in the life span in these patients could modify these results in the future, due to recent improvements in the HIV infection treatment.

Human herpesvirus 8 and Epstein Barr-virus in a cutaneous B-cell lymphoma and a malignant cell line established from the blood of an AIDS patient

Human Herpesvirus 8 (HHV-8) has been consistently associated with Primary Effusion Lymphoma (PEL or body-cavity-based lymphoma) but not with other lymphomas. This paper reports on an AIDS patient without obvious malignant effusion in body cavities but with a cutaneous lymphoma where HHV-8 and Epstein-Barr virus (EBV) were detected by PCR and electron microscopy. Both viruses were also detected in all the cells of a malignant cell line (BBG1) established from the patient's peripheral blood mononuclear cells. As in PEL and PEL-derived cell lines, both the tumor and the lines lacked B-antigen expression in immunological studies but were of the same B origin as shown by clonal immunoglobulin gene rearrangements. In contrast to other co-infected cell lines, BBG1 and subclones spontaneously expressed the HHV-8 lytic antigens p40, p27, p60 and the EBV transforming latent antigen EBNA2. These data suggest that the clinical and biological features of HHV-8-and EBV-associated lymphomas could be wider than has been described to date in PEL particularly with the in vivo presence of circulating malignant dually-infected cells engaged in a spontaneous HHV-8 lytic infection.

Capillary electrophoresis-single-strand conformation polymorphism analysis for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis

We used capillary electrophoresis-single-strand conformation polymorphism (CE-SSCP) analysis of PCR-amplified 16S rRNA gene fragments for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli isolated from patients with cystic fibrosis (CF). Target sequences were amplified by using forward and reverse primers labeled with various fluorescent dyes. The labeled PCR products were denatured by heating and separated by capillary gel electrophoresis with an automated DNA sequencer. Data were analyzed with GeneScan 672 software. This program made it possible to control lane-to-lane variability by standardizing the peak positions relative to internal DNA size markers. Thirty-four reference strains belonging to the genera Pseudomonas, Brevundimonas, Burkholderia, Comamonas, Ralstonia, Stenotrophomonas, and Alcaligenes were tested with primer sets spanning 16S rRNA gene regions with various degrees of polymorphism. The best results were obtained with the primer set P11P-P13P, which spans a moderately polymorphic region (Escherichia coli 16S rRNA positions 1173 to 1389 [M. N. Widjojoatmodjo, A. C. Fluit, and J. Verhoef, J. Clin. Microbiol. 32:3002-3007, 1994]). This primer set differentiated the main CF pathogens from closely related species but did not distinguish P. aeruginosa from Pseudomonas alcaligenes-Pseudomonas pseudoalcaligenes and Alcaligenes xylosoxidans from Alcaligenes denitrificans. Two hundred seven CF clinical isolates (153 of P. aeruginosa, 26 of Stenotrophomonas maltophilia, 15 of Burkholderia spp., and 13 of A. xylosoxidans) were tested with P11P-P13P. The CE-SSCP patterns obtained were identical to those for the corresponding reference strains. Fluorescence-based CE-SSCP analysis is simple to use, gives highly reproducible results, and makes it possible to analyze a large number of strains. This approach is suited for the rapid identification of the main gram-negative nonfermenting bacilli encountered in CF.

Novel immunoblot assay using four recombinant antigens for diagnosis of Epstein-Barr virus primary infection and reactivation

A new immunoblot assay, composed of four Epstein-Barr virus (EBV)-encoded recombinant proteins (virus capsid antigen [VCA] p23, early antigen [EA] p138, EA p54, and EBNA-1 p72), was compared with an immunofluorescence assay on a total of 291 sera. The test was accurate in 94.5% of cases of primary EBV infection, while an immunoglobulin G anti-VCA p23 band with strong intensity correlated with reactivation.

Effectiveness of a manual disinfection procedure in eliminating hepatitis C virus from experimentally contaminated endoscopes

BACKGROUND

Transmission of hepatitis C virus (HCV) through endoscopy has been reported, but the implications as a public health concern remain controversial. This study investigated the degree to which a thorough manual cleaning-washing-disinfection procedure can decontaminate all channels of a flexible submersible endoscope experimentally contaminated with HCV.

METHODS

To assess the accuracy of the method currently in use, the initial investigation focused on sampling effectiveness. Nine endoscopes were contaminated with high-titer HCV-positive plasma and flushed with 150 mL of sampling solution (distilled water) before disinfection. To assess the effectiveness of the disinfection procedure, the following sequence was performed on another 10 endoscopes: inoculation, disinfection, and sampling. After concentration residual viruses were detected by means of RNA amplification with commercial assays.

RESULTS

The study showed that sampling alone can reduce viral titer to one-fourth its original value. Within the limits of this method, HCV RNA was never detected by means of polymerase chain reaction after disinfection, whereas all internal amplification controls were positive. This reduction to less than 1/100,000 of original titer exceeds the criterion expected for the virucidal activity of disinfectants.

CONCLUSIONS

The results of this in vitro experiment provided evidence that patient-to-patient endoscopic transmission HCV can be reduced, if not eliminated, with the current mechanical cleaning-washing-disinfection procedure.

Serologic and genetic characterization of HIV type 1 subtypes on Reunion Island

The aim of this study was to determine the HIV subtypes present on Reunion Island, a French island located in the Indian Ocean, where the first case of AIDS was diagnosed in 1987. Paired sera and blood samples were collected between September 1996 and September 1997 from 53 HIV-1-positive patients. Subtyping was performed by serotyping with a previously described subtype-specific enzyme immunoassay (SSEIA) and by genotyping with the heteroduplex mobility assay (HMA). When samples gave uninterpretable results with either of the methods, or discordant results, the V3 env region was sequenced and genetic subtypes were determined by phylogenetic analysis. Genetic subtyping showed that 48 of 53 patients were infected with HIV-1 subtype B (90.5%). This high prevalence of subtype B on Reunion Island is probably due to the regular exchanges with metropolitan France. The other five patients were infected with subtype A (9.5%); they had been directly linked to African populations. Of the 48 subtype B samples, 44 (91.7%) were correctly subtyped by SSEIA and 43 (89.6%) by HMA. However, the SSEIA did not allow the subtyping of A strains in three of five patients. Thus, the SSEIA could be an alternative routine technique for screening subtype B versus nonsubtype B HIV-1 strains.

Interactions of pathogenic Neisseria with host cells. Is it possible to assemble the puzzle?

Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens that have to interact with mucosa and/or cellular barriers for their life cycles to progress. Even though they both give rise to dramatically different diseases, the use of in vitro models has shown that most of the mechanisms mediating cellular interactions are common to N. meningitidis and N. gonorrhoeae. This suggests that bacterial cell interactions may be essential not only for pathogenesis but also for other aspects of the bacterial life cycle that are common to both N. meningitidis and N. gonorrhoeae. This manuscript will review the most recent developments concerning the mechanisms mediating cellular interaction of pathogenic Neisseria and will then try to put them into the perspective of pathogenesis and bacterial life cycle.

Monitoring rotavirus environmental contamination in a pediatric unit using polymerase chain reaction

Rotavirus environmental contamination in a pediatric unit was investigated. Surfaces were swabbed, then viruses eluted, ultracentrifuged, and detected by polymerase chain reaction (PCR) amplification. Of 55 samples, 25 (46%) tested positive. Rotavirus RNA was more prevalent on surfaces in direct contact with children (thermometers and play mats) than on other environmental surfaces (washbasins, door handles, etc). PCR has proved useful for monitoring rotavirus environmental contamination.

[Dysthymic disorders]

Long lasting, low intensity depressive episodes have been diversely integrated according to the classifications types or the psychodynamic points of view. The concept of anxious persistent lasting depression, neurotic depressive states, neurotic depression ... have been unified into the dysthymic disorder category of the DSM classification. This concept unification have been a topic of dispute considering that dysthymic disorder was a restrictive, heterogeneous an extensively comorbid diagnosis. Nevertheless the definition of this category offers the opportunity to place the notions of temperament, personality, adjustment disorder. Including dysthymic disorders as a category inside of the mood disorders classification suggests the interest of using an antidepressive medication in presence of chronic depressive states not included in the major depressive disorder category.