High incidence but low burden of coronaviruses and preferential associations between respiratory viruses.

Respiratory viruses are the leading cause of acute infections in humans. However, the burden of certain respiratory viruses, such as coronaviruses, and the relevance of viral coinfections remain unclear. In this study, we investigated the distribution and seasonal occurrences of respiratory viruses detected by multiplex molecular assay in 6,014 samples from 2008 to 2011 in a French hospital. We assessed the detection frequencies of 14 respiratory viruses and their clinical impact in immunosuppressed and nonimmunosuppressed patients. Furthermore, we explored the preferential association patterns between respiratory viruses in multiple infections. Our results indicated that human rhinovirus/enterovirus (HRV/EV) and coronavirus (HCoV) were frequently detected in respiratory samples (48.81% and 11.74% of infected samples, respectively), and the detection frequencies of these viruses were further increased in immunosuppressed patients. The most common subtypes of HCoV were HCoV-229E (33.80%) and HCoV-HKU1 (32.39%). A sharp increase in the detection frequencies of HCoV-229E and HCoV-HKU1 over several months suggested that these subtypes were epidemic in our population. In immunosuppressed patients, HCoV contributed to upper respiratory tract infections (52%). Evidence did not support lower respiratory tract infections exclusive to a unique HCoV infection. In multiply infected individuals, determined in 6.3% of samples, HRV/EV and HCoV were detected in 33.29% and 22.90% of samples, respectively. Interestingly, nearly 50% of HCoV infections were detected in association with another virus. Since the distributions of respiratory viruses in multiply infected patients were subject to preferential association patterns between viruses, we propose complex interactions between different respiratory viruses and host factors.

[Tropism of hepatitis C virus for leukocytes-- importance of the analysis of viral E1 and E2 envelope glycoprotein genes by sequencing]. / Tropisme leucocytaire du virus de l'hépatite C - intérêt de l'analyse des séquences des gènes des glycoprotéines d'enveloppe virales E1 et E2.

The ability of hepatitis C virus (HCV) to infect leukocytes could favour HCV pathogenesis. Although viral infection of these immunocompetent cells is poorly (or not) productive, the impact on their immunomodulatory functions could be important. Viral envelope glycoproteins E1 and E2, because of their crucial role in the recognition of viral receptors on permissive cells, could contribute to viral leukocytic tropism and, as a consequence, to the pathophysiology of HCV chronic infection.

Hepatitis C virus structural proteins do not prevent human dendritic cell maturation.

AIM: Infection with hepatitis C virus (HCV) results in chronic hepatitis in more than 70% of cases. Alterations in the maturation of dendritic cells (DC) might play a role in the immune system's inability to eliminate the virus, although viral factors that could be involved have not been identified. This study in vitro investigated whether HCV structural proteins affect maturation of monocyte-derived DC. METHODS: HCV proteins (core, E1, E2) were expressed by transduction with recombinant adenoviruses of immature DC. The ability of these transduced DC to respond to a maturation stimulus was evaluated by measuring cell surface markers, allogenic lymphocyte stimulation and interleukin (IL)-12 production. RESULTS: Expression of HCV structural proteins did not modify DC maturation in the presence of lipopolysaccharide, as determined by their phenotype and stimulatory functioning. IL-12 secretion was not affected by HCV protein expression in mature DC. CONCLUSION: Our results suggest that HCV structural proteins do not affect maturation of monocyte-derived DC by lipopolysaccharide. These findings are important for further studies to clarify the pathogenesis of chronic HCV infection and towards the rational design of cellular vaccine approaches for immunotherapy against hepatitis C.

[Neutralizing antibodies in hepatitis C virus infection]. / Anticorps neutralisants dirigés contre le virus de l'hépatite C.

Hepatitis C virus (HCV) results in persistent infection in more than 70% of infected individuals despite the development of humoral and cellular immune responses. Following infection, although antibodies targeting epitopes of both structural and non structural proteins are elicited, the virus evades antibody-mediated neutralization. Studies of host neutralizing responses against HCV have been limited by the lack of a convenient tissue culture system for HCV infection. In the past five years in vitro models have been developed to characterize interaction of HCV glycoproteins with host cell entry factors and detect antibodies interfering with HCV entry and infection. These models have been used to characterize targets of neutralizing responses and better understand their impact on the pathogenesis of infection.

[Respiratory tract infections in institutions for elderly people: the GROG Géronto-Alsace, strategy of surveillance and alert]. / Infections respiratoires aiguës dans les collectivités de personnes âgées: le GROG Géronto-Alsace, une démarche expérimentale de surveillance et d'alerte.

OBJECTIVE: Outbreaks of respiratory tract infections are common in institutions for elderly people. The objective of our study was the implementation of a network including 11 institutions to determine the frequency of such outbreaks. Using the collected data, criteria and alert levels are defined to assess the level of respiratory tract infections and develop appropriate interventions. METHODOLOGY: Prospective surveillance for respiratory tract infection was conducted in 11 institutions in Alsace for 2 years. Clinical definitions were used to identify the infected residents. For the identification of influenza virus, nasopharyngeal samples using swabs were obtained and rapid tests (immunoassay) were performed. RESULTS: During the surveillance, outbreaks were identified in institutions. The same observations occurred in all institutions at the same time. Alert levels were defined in order to characterize the outbreak period and to improve detection and control of outbreaks of respiratory tract infections. CONCLUSION: Ours findings show the importance of an adequate surveillance and networks improve the impact of such measures.

Atypical symptoms in patients with herpesvirus DNA detected by PCR in cerebrospinal fluid.

BACKGROUND: Polymerase chain reaction (PCR) detection of herpesvirus DNA in cerebrospinal fluid (CSF) is an important tool in the diagnosis of central nervous system (CNS) syndromes. The corresponding viral infections present with diverse clinical signs, which are often classical although no sign can be considered as specific. This retrospective study aims to describe atypical symptoms in patients with herpesvirus DNA detected in CSF by PCR. A total of 3452 cerebrospinal fluid samples from patients with suspected herpesvirus infection of the CNS were investigated between 1998 and 2003 in our clinical virology laboratory. "In-house" PCRs for each herpesvirus [herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein Barr virus (EBV), or human herpes virus 6 (HHV6)] were used until 2001 and a commercially available "Herpes Consensus PCR" was used thereafter. One of the five herpesviruses investigated in this study was found in 71 (2.1%) of CSF samples (37 HSV, 14 VZV, 1 CMV, 9 EBV and 10 HHV6). These samples were obtained from 62 patients whose clinical findings were generally consistent with the PCR data. However, some little known features of herpesvirus-related symptoms, such as partial seizure associated with HSV infection, and unusual VZV or HHV6-related myelitis were also observed.

Clinical relevance of herpes simplex virus viremia in Intensive Care Unit patients.

OBJECTIVES: To determine the clinical relevance of herpes simplex virus (HSV) viremia episodes in critically ill adult patients. METHODS: 1556 blood samples obtained for HSV PCR analysis in Intensive Care Unit (ICU) patients over 4 years were retrospectively analyzed, focusing on the comprehensive analysis of 88 HSV-viremic patients. RESULTS: HSV DNA was detected in 11.8% of samples from the ICU. HSV viral loads remained below 5×10(2) copies/ml in 68.2% of patients and exceeded 10(4) copies/ml in 7.9%. Episodes of HSV-viremia correlated with immunosuppressed status and mechanical ventilation in 79.5% and 65.9% of patients, respectively. Only a subset of patients exhibited HSV-related organ damage, including pneumonia and hepatitis (10.2% and 2.3%, respectively). The mortality rate in HSV-viremic patients was not significantly increased compared to the overall mortality rate in the ICU (27.3% vs. 22.9%, p = 0.33). Only patients with high HSV viral loads tended to have a higher, though non-significant, death rate (57.1%, p = 0.14). CONCLUSIONS: Our results suggest HSV viremia is common in ICU patients, potentially favored by immunocompromised status and mechanical ventilation. The global impact of HSV-viremia on mortality in the ICU was low. Quantifying HSV DNA may help identifying patients at-risk of severe HSV-induced symptoms.

Identification of a duplicated V3 domain in NS5A associated with cirrhosis and hepatocellular carcinoma in HCV-1b patients.

BACKGROUND: The NS5A protein of the hepatitis C virus has been shown to be involved in the development of hepatocellular carcinoma. OBJECTIVES: In a French multicenter study, we investigated the clinical and epidemiological features of a new HCV genotype 1b strain bearing a wide insertion into the V3 domain. STUDY DESIGN: We studied NS5A gene sequences in 821 French patients infected with genotype 1b HCV. RESULTS: We identified an uncharacterized V3 insertion without ORF disruption in 3.05% of the HCV sequences. The insertion comprised 31 amino-acids for the majority of patients; 3 patients had 27 amino-acids insertions and 1 had a 12 amino-acids insertion. Sequence identity between the 31 amino-acids insertions and the V3 domain ranged from 48 to 96% with E-values above 4e(-5), thus illustrating sequence homology and a partial gene duplication event that to our knowledge has never been reported in HCV. Moreover we showed the presence of the duplication at the time of infection and its persistence at least during 12 years in the entire quasispecies. No association was found with extrahepatic diseases. Conversely, patients with cirrhosis were two times more likely to have HCV with this genetic characteristic (p=0.04). Moreover, its prevalence increased with liver disease severity (from 3.0% in patients without cirrhosis to 9.4% in patients with both cirrhosis and HCC, p for trend=0.045). CONCLUSIONS: We identified a duplicated V3 domain in the HCV-1b NS5A protein for the first time. The duplication may be associated with unfavorable evolution of liver disease including a possible involvement in liver carcinogenesis.

High hepatitis C viraemia and impaired antibody response in patients coinfected with HIV.

OBJECTIVE: To compare hepatitis C virus (HCV) load in patients infected with HCV alone and those coinfected with HIV, and to evaluate the antibody response to HCV in the case of HIV infection. DESIGN: Patients coinfected with both HCV and HIV have been shown to develop hepatic changes more rapidly, which may be due to an interaction between HCV and HIV. In a prospective study, serum samples were taken from 150 patients. METHODS: Using reverse transcription followed by polymerase chain reaction and the branched DNA assay, we detected HCV RNA in 75 patients coinfected with HIV and HCV and in 75 patients infected with HCV alone. The HIV RNA was also quantified by the branched DNA assay and the p24 antigenaemia was determined by enzyme-linked immunosorbent assay. The immune response to HCV was studied in the 150 patients by the use of third generation recombinant immunoblot assay (RIBA). RESULTS: Although a comparable number of patients had detectable HCV viraemia in both groups, HCV RNA was quantifiable in 79% of HIV-positive patients and in only 43% of HIV-negative patients (P < 10(-5)), and the mean HCV RNA level was much higher in the HIV-positive group than in the HIV-negative group (P < 10(-7)). The quantity of HCV RNA did not correlate with the CD4 count, p24 antigenaemia or HIV RNA level. The analysis of RIBA showed 14.7% indeterminate or negative results in the HIV-positive group and only 4% indeterminate results in the HIV-negative group. HIV-positive patients had reactivity to less antigen bands than HIV-negative patients (P < 10(-3)), and they had a weaker reactivity to c100, c33c and NS5 antigen bands than HIV-negative patients. CONCLUSION: Our results show that in the case of HIV infection, the HCV RNA levels are strongly increased, but HCV load is not linked to the immunosuppression induced by HIV; therefore, the present data do not support the hypothesis of a direct interaction between HIV and HCV.

Ultrastructural observations in hepatitis C virus-infected lymphoid cells.

It is currently unclear whether the hepatocellular damage in chronic hepatitis C virus (HCV) infection is produced through the intrahepatic action of the anti-HCV immune response or through a direct cytopathic effect. In order to investigate the features of HCV replication (morphogenesis and cytopathic effect), we studied the infection of a permissive lymphocytic B cell line, Daudi cells, which were infected with sera of HCV-positive patients, and were examined after various time points under electron microscope. Viral genomic RNA was detected by in situ hybridization, and apoptosis with the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method. The amount of viral genomic RNA was observed to increase during infection. HCV replicated rapidly, since characteristics of viral morphogenesis resembling those of yellow fever virus in a hepatoma cell line could be found 2 days after infection. These included the following: a) several viral particles identical in size (about 42 nm) and structure (a spherical 30-nm-sized electron-dense nucleocapsid surrounded by a membrane) to yellow fever virus were present in the cytoplasm of cells displaying already typical signs of the early stage of apoptosis; b) numerous membrane-bound organelles and in particular the endoplasmic reticulum and vacuoles were observed; c) proliferation of membranes was apparent; and d) intracytoplasmic electron-dense inclusion bodies which have been demonstrated to correspond to nucleocapsids for other flaviviruses were detected. Several cells presented electron-dense areas in the endoplasmic reticulum displaying 30-nm circular structures lying among an amorphous material. Striking cytopathic features with ballooning, extremely enlarged vacuoles and signs of apoptosis were found in cells often containing sequestered aggregates of virus-like particles. By in situ hybridization we found that such enlarged cells contained HCV RNA. Our results thus indicate that the ultrastructural features of HCV viral particles and their morphogenesis resemble that of yellow fever virus and dengue virus. In Daudi cells, HCV infection seems to rapidly trigger apoptotic cell death, and efficient release of viral particles does not seem to take place.

Chronic urticaria is not significantly associated with hepatitis C or hepatitis G infection: a case-control study.

OBJECTIVE: To study the prevalence of hepatitis C virus (HCV) and hepatitis G virus (HGV) infection in patients with chronic urticaria. DESIGN: Prospective case-control study and literature review. SETTING: Dermatology department of an academic medical center in Strasbourg, France. PATIENTS: One hundred ten consecutive patients with typical urticaria lasting longer than 2 months were seen between March 1, 1997, and August 31, 1998. None had a history of viral hepatitis. Age- and sex-matched patients (n = 110) seen in the same department and during the same period were included for controls. None of the controls had a history of urticaria, pruritic dermatosis, or hepatitis. MAIN OUTCOME MEASURES: The detection of HCV antibodies through a third-generation enzyme-linked immunosorbent assay. To detect early HCV infection without plasmatic antibodies, genomic amplification of HCV RNA was carried out in all patients using 2 different methods. Hepatitis G virus RNA was detected only by genomic amplification. All measures were planned before data collection. RESULTS: Antibodies to HCV were found in 1 patient with urticaria and in 1 of the control group (0.9% of each group). None had circulating HCV RNA, and liver function test results were within the reference range. Genomic amplification without HCV antibodies was not observed. Two patients with urticaria and 2 of the control group (1.8% of each group) had circulating HGV RNA, but they had neither coinfection with HCV nor changes in their liver function test results. CONCLUSIONS: Systematic HCV screening in patients with chronic urticaria is not cost-effective, at least in Europe, because hepatitis C rates were similar to those of the general population. We could not confirm the hypothesis that urticaria occurs in an early phase of HCV infection-ie, before evidence of HCV can be detected by serologic testing. Hepatitis C virus is unlikely to be the cause of urticaria in the infected patient detected in this study because of the absence of HCV RNA and changes on liver function tests. Hepatitis G virus is also unlikely to be a cause of urticaria, as the rate of HGV positivity in this study was even lower than that in the general French population.

Abnormal urinary coproporphyrin levels in patients infected by hepatitis C virus with or without human immunodeficiency virus. A study of 177 patients.

OBJECTIVE: Many cases of porphyria cutanea tarda have been described in association with human immunodeficiency virus (HIV) infection in young individuals. The link between hepatitis C virus (HCV) and porphyria cutanea tarda is even stronger as more than 50% of patients who have this diagnosis in Italy, France, or Spain are also infected by HCV. To study the role of viral infections on the metabolism of porphyrins, we measured the urinary porphyrin levels in patients with HIV and HCV infections. DESIGN: Survey; prospective study. SETTING: University Hospital of Strasbourg, France. PATIENTS: Sixty-one HIV-positive patients, 56 HCV-positive patients, 60 HIV- and HCV-positive patients, and 51 HIV- and HCV-negative control subjects were randomly selected. None had clinical signs of porphyria or a familial history of porphyria. MAIN OUTCOME MEASURES: The porphyrin-excretion profile was determined by high-performance liquid chromatography on fresh urine samples. The HIV and HCV viremias were quantified in the serum by the branched DNA assay. Measures were planned before data collection began. RESULTS: The porphyrin-excretion profile typical of porphyria cutanea tarda was found in only 1 of 177 patients. In the remaining 176 patients, the mean coproporphyrin level was significantly raised in HCV-positive patients and even higher in patients who were HIV- and HCV-positive. The coproporphyrin level was not correlated to the alanine aminotransferase level, the CD4+ cell count, or the HCV and HIV viremias. CONCLUSIONS: In cases of infection with HIV, HCV, or both, the development of a porphyria cutanea tarda urinary profile is a rare event (0.56% in this study), but coproporphyrin excretion is increased. This could be related to hepatic changes induced by the viruses. Our results do not support the hypothesis of a direct viral effect on the porphyrin metabolism. Infection with HIV, HCV, or both may be a major triggering factor, but is not sufficient to induce porphyria.

[Emergence of resistant hepatitis B virus strains during long-term lamivudine therapy in human immunodeficiency virus co-infected patients]. / Emergence de souches résistantes de virus de l'hépatite B, sous traitement prolongé par lamivudine, chez des malades co-infectés par le virus de l'immunodéficience humaine.

Seven patients co-infected with hepatitis B virus (HBsAg and HBeAg carriers, quantifiable HBV DNA with the bDNA technic) and human immunodeficiency virus received a triple antiretroviral combination therapy, including lamivudine (150 mg twice a day). Hepatitis B viral load rapidly became undetectable in 6/7 patients. It remained below the level of detection in 2 subjects, after 20 and 22 months of treatment, with one of them achieving HBeAg/anti-HBe seroconversion. However, in the other 4 individuals, hepatitis B viremia increased again after 8 to 16 months of lamivudine-containing regimen. The last patient was a non-responder. The 4 relapsers developed a double mutation Leu(528) for Met(528) and Met(552) for Val(552), on hepatitis B virus polymerase, either concomitant (M8 and M16) with a hepatitis B virus DNA increase, or 2 months earlier (M10 and M12). The high frequency of hepatitis B virus resistance to lamivudine emphasizes the necessity of identifying more effective strategies, such as double combination therapies.

[Commercial methods for the diagnosis of CMV infection after organ or bone marrow transplantation]. / Utilisation des tests commercialisés pour le diagnostic d'une infection a CMV chez les greffés de moelle et d'organe.

Cytomegalovirus infection is a major problem for transplant recipients. It has been recently shown that the rate of increase in viral load correlate with CMV disease in transplant recipients. The risk is very high in persons undergoing bone marrow transplantation and in some cases preemptive therapy is used as soon as viral replication is proven. In this context the assays based on the detection of CMV in leukocytes are found to be the most sensitive. After renal transplantation a number of studies have demonstrated that the amount of CMV DNA is significantly associated with disease development. But there is no consensus with regard to the cut-off level predictive of CMV disease because of the heterogeneity of the assays used. Recent studies carried out with commercial assays detecting CMV DNA in leukocytes or plasma have shown that the performances of both are equivalent and that by using a receiver operator curve analysis a cut-off viral load can be determined which maximizes the clinical utility of these assays.

[Porphyria cutanea tarda and hepatitis C virus infection. Clinical and virological study]. / Porphyrie cutanée tardive et infection par le virus de l'hépatite C. Etude clinique et virologique.

INTRODUCTION: The role of hepatitis C virus (HCV) infection in porphyria cutanea tarda (PCT) is probable since the global antibody prevalence among PCT patients is about 70 p. 100. The purpose of this study was to evaluate the virological characteristics in 12 patients with sporadic PCT and one with familial PCT. METHODS: Anti-HCV antibodies were detected by enzyme-linked immunosorbent assay and confirmed by recombinant immunoblot assay. Hepatitis B virus (HBV) and anti-human immunodeficiency virus (HIV) markers were also determined. The polymerase chain reaction (PCR) was performed in order to detect: 1) both positive and minus HCV strands, 2) HCV RNA titer and 3) HCV RNA genotype. RESULTS: Seven of the 12 patients with sporadic PCT were HCV positive and the patient with familial PCT was HCV negative. The age of onset of PCT was significantly lower in HCV positive patients than in HCV negative patients (p < 0.02). The HCV RNA was detected in all patients who had HCV antibodies, and the replicative intermediate of HCV was detected in 3 of them. The positive RNA titer ranged from 1/10 to 1/10(6). Four patients were infected by HCV genotype I, 2 by genotype II and 1 patient was coinfected by type I and type II. Three of the 7 HCV positive patients also had HBV antibodies, but HBV DNA was never detected. All patients were HIV negative. DISCUSSION: The HCV infection rate was high in this series (58 p. 100), and all HCV infected patients had HCV RNA, reflecting an active replication of the virus. The young age of onset of PCT suggests that HCV is a major triggering factor of PCT. Nevertheless, the clinical changes of PCT were not related to the virological findings, suggesting an indirect role of HCV.

[Does the nasopharyngeal samples virological analysis reflect the lower respiratory tract infection in children population? A PCR multiplex study]. / L'analyse virologique des aspirations nasopharyngées reflète-t-elle l'infection respiratoire basse chez l'enfant ? Étude en PCR multiplex.

Respiratory tract infections are frequent in young children and are related to viruses in most cases. Multiplex Polymerase chain reaction (PCR) based techniques are valuable tools for describing the spectrum of such viruses. The goal of this study was to assess the correlation of virus detection in samples obtained by nasopharyngeal aspiration and by bronchoalveolar lavage. Both samples were taken at the same time in 30 children with lower respiratory tract infection, and were analyzed by multiplex virus PCR (xTAG™ RVP). A strong correlation has been found (P = 0.0002) and the most frequently isolated virus was the entero-rhinovirus spp. These results strengthen the opinion that viruses colonize both the upper and lower respiratory tract. Nasopharyngeal samples should be sufficient to the diagnosis of lower respiratory tract viral infection in immuno-competent children.

[Clusters of respiratory tract infections and alert strategy in nursing homes]. / Cas groupés d'infections respiratoires aiguës et stratégie d'alerte en institutions de personnes âgées.

OBJECTIVE: Outbreaks of acute respiratory infections (ARI) are common in institutions for elderly people. We had for objective to investigate clusters of cases (lower respiratory tract infection and influenza-like illness [LRTI/ILI]) in order to improve and validate alert strategies in these institutions. METHODOLOGY: Prospective surveillance for LRTI/ILI was implemented in 11 institutions in Alsace, over five years. Clinical criteria were used to identify infected residents and clusters. Nasopharyngeal swabs were collected and rapid tests (Immunoassay) were performed to identify the influenza virus. RESULTS: The three week periods were analyzed if three cases or more were recorded during the first week. This analysis demonstrated an important risk of epidemic when this number of cases was reached in healthcare units. The influenza virus (10 clusters) and respiratory syncytial virus ([RSV], two clusters) were identified. CONCLUSION: The authors confirmed and emphasized the importance of adequate surveillance for clusters of respiratory tract infection cases. Early identification of an outbreak (three cases) is an important point to prevent transmission, especially during epidemic periods and if a virus is identified in the unit or institution.

[Immunoassay rapid test for influenza diagnosis in institutions for elderly people: a four-year surveillance with the GROG Géronto-Alsace]. / Tests rapides de surveillance (TRS) de la grippe en établissements accueillant des personnes âgées: évaluation de quatre années d'utilisation dans le cadre du réseau GROG Géronto-Alsace.

OBJECTIVE: Outbreaks of acute respiratory infections (ARI) are common in institutions for elderly people. The objective of our study was the assessment of immunoassay rapid test used for influenza diagnosis in institutions for elderly people. METHODOLOGY: Prospective surveillance for ARI was conducted in 11 institutions in Alsace over a four-year period. Clinical case definitions are used to identify the infected residents. For the identification of influenza virus, nasopharyngeal swabs are obtained and rapid tests (immunoassay) are performed. RESULTS: Influenza virus was identified with immunoassay rapid test. Then, prophylaxis according to the Conseil supérieur d'hygiène publique de France guidelines was implemented. Nevertheless, the use of the rapid test was not frequent in the individual institution and the information recorded at the GROG Géronto-Alsace level could be use to inform the institutions when it is important to perform these rapid tests. CONCLUSION: Ours findings show the value of the rapid test used in the influenza surveillance and how the networks could help to improve their uses.