Search PubMed⌕ Search

Biomedical subjects

B Pozzetto

Publications and source records attributed to B Pozzetto.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Evaluation of the interest of semen culture before cryoconservation].

OBJECTIVES: French guidelines recommend screening all patients for virus infection prior to cryopreservation of their semen. In case of viral risk, the use of specific high secure CBS straws is recommended. The objective of this work was to evaluate the microbiological risk by testing all semen samples before cryopreservation. PATIENTS AND METHODS: Fifty one patients underwent a semen culture before cryopreservation. RESULTS: The fifty one patients were classed into 3 groups following semen culture results: group I: negative culture (39/51, 76.47%), group II: positive culture with microbiological contamination (7/51, 13.73%) and group III: positive culture with pathogen (5/51, 9.8%). For 3 patients of the latter group, we tested a three-layer density gradient to eliminate bacteria before Assisted Reproductive Techniques. DISCUSSION AND CONCLUSIONS: This paper discusses the risks related to microbiological contamination and the options available in this case.

Bacterial Infections↗
PubMed2002

[Outbreaks due to respiratory syncytial virus and influenzavirus A/H3N in institutionalized aged. Role of immunological status to influenza vaccine and possible implication of caregivers in the transmission].

OBJECTIVES: Report of epidemiological, clinical and virological data collected from the prospective surveillance of febrile episodes observed in aged residents of a long-stay care unit of 33 beds, at the University Hospital of Saint-Etienne, during the 1997-1998 winter season. METHODS: Systematic collection of clinical and biological data from febrile patients (> or = 38 degrees C) on a form, including virological findings obtained from a nasal swab and paired serum specimens. RESULTS: From 38 patients (37 of them having been vaccinated against influenza in October 1997), 18 febrile episodes were recorded in 16 subjects, including 3 respiratory syncytial virus infections and a late-occurring outbreak (March 1998) of influenza due to a A/H3N2 strain (15 cases, 14 of them virologically confirmed). No death was noted after the influenza outbreak. In 8 of the 9 tested patients with influenza, "protective" titres of antibodies directed towards the hemagglutinin of the vaccinal strain were present by radial hemolysis test three months before the beginning of the outbreak. During the influenza outbreak, the attack rate of symptomatic infection was 45.5% in elderly and 47.5% in healthcare workers (mainly unvaccinated). The occurrence of the first cases in the latter suggests their possible role in the transmission of the virus to the aged. CONCLUSION: This study underlines the epidemic circulation of multiple respiratory viruses during the same winter season in long-stay care facilities, the occurrence of clinical influenza infections in vaccinated patients exhibiting protective antibody titres and the role of unvaccinated healthcare workers in the propagation of influenza in institutionalised aged.

Adult↗
PubMed2002

Detection of GB virus C/hepatitis G virus in semen and saliva of HIV type-1 infected men.

OBJECTIVE: To investigate the presence of the genome of GB virus C/hepatitis G virus (GBV-C/HGV) in semen and saliva from HIV-1-infected men. METHODS: Samples of blood from 33 men seropositive for HIV-1 were tested for the presence of GBV-C/HGV markers of infection, RNA by RT-PCR, and anti-E2 antibodies by ELISA, respectively. The cell-free fractions of seminal fluid and saliva samples of the patients with positive blood samples for GBV-C/HGV RNA or anti-E2 antibodies were then analyzed for the presence of the RNA of this virus. In addition, six semen samples and 11 saliva samples from GBV-C/HGV-negative men were tested. RESULTS: The GBV-C/HGV RNA tested by RT-PCR was recovered from blood in 11 patients of 33 (33.3%), and the antibodies to E2 envelope protein were detected in six patients (18.2%). Since no patient was positive for both markers, the overall prevalence of GBV-C/HGV infection was 51.5% in the studied population. Four-all belonging to the homosexual risk group-of the 17 men with markers to GBV-C/HGV in blood were found to be positive for GBV-C/HGV RNA in mucosal samples: two of them exhibited genomic RNA in both semen and saliva, and two others were positive for semen only. The absence of inhibitors of the PCR technique was confirmed in all mucosal fractions found negative for GBV-C/HGV RNA, except for one saliva sample and one seminal fluid sample. CONCLUSION: These results confirm the high prevalence of GBV-C/HGV infection in patients infected with HIV-1 by sexual exposure and the presence of GBV-C/HGV RNA in seminal fluid and saliva of men with markers of this virus in the blood, suggesting that mucosal fluids could be a potential source for the spread of the GBV-C/HGV infection.

12E7 Antigen↗
PubMed2002

Pregnancy after safe IVF with hepatitis C virus RNA-positive sperm.

In France, assisted reproductive technology (ART) for hepatitis C virus (HCV)-infected patients is now subject to strict control after the publication of recent guidelines. Infertile serodiscordant couples (HCV-viraemic men and their seronegative female partners) require special care to carried out in designated 'viral risk' laboratories. Twelve sequential semen samples taken from an HCV chronically infected patient were analysed within 22 months. HCV RNA was detected in all the seminal plasma sampled before antiviral treatment with relatively high viral loads, and in two of the corresponding fractions of motile sperm obtained after a gradient selection, suggesting that a contamination risk by HCV through ART cannot be excluded. When the selection of sperm on a discontinuous gradient was followed by an additional swim-up step, HCV RNA was never detected in the motile sperm suspension that was frozen in highly secure straws. IVF was performed using cryopreserved sperm that tested negative for HCV RNA, resulting in a pregnancy. One month after embryo transfer, testing for HCV RNA and antibodies in the woman gave negative results.

Adult↗
PubMed2001

Prospective study of nosocomial colonization and infection due to Pseudomonas aeruginosa in mechanically ventilated patients.

OBJECTIVE: To investigate the respective contribution of endogenous and exogenous transmission of Pseudomonas aeruginosa in the colonization of lungs in the mechanically ventilated patient, to estimate the role of P. aeruginosa colonization in the occurrence of severe infections, and to extrapolate appropriate control measures for the prevention of P. aeruginosa ventilator-associated pneumonia. DESIGN: Prospective study of the presence of P. aeruginosa (in stomach fluid, throat specimens, stool, and sputum) on admission, twice a week throughout the patient's stay, and in their environment. O-serotyping, pulsed-field gel electrophoresis, and arbitrarily-primed polymerase chain reaction were used to characterize the strains. SETTING: The two intensive care units (ICUs 1 and 2) of a university hospital. PATIENTS: During a 6-month period, 59 patients were included (21 in ICU 1 and 38 in ICU 2). RESULTS: P. aeruginosa was isolated in 26 patients, including ten pneumonia cases and seven colonizations on admission. The incidence of acquired colonization was statistically different between the two ICUs: 5.5 and 20.5 per 1000 days of mechanical ventilation, in ICUs 1 and 2, respectively. Endogenous acquisition was the main origin of P. aeruginosa colonization (21 of 26 patients) and the upper respiratory tract was the main bacterial reservoir in broncho-pulmonary colonization and infection. However, during the 6-month period of the study, a multidrug-resistant strain of P. aeruginosa O:11, isolated in the sink of the room of 12 patients, was found responsible for two colonizations (1 digestive, 1 throat/lungs) and one pneumonia. As a whole, from 26 cases of colonization/infection with P. aeruginosa, 5 were related to an exogenous contamination (environmental reservoir in 4 patients and cross-contamination in one patient). CONCLUSIONS: These results emphasize the need for applying various infection control measures to prevent colonization of patients with P. aeruginosa, including strategies to limit the potential of sinks from acting as a source or reservoir for this bacterium.

Aged↗
PubMed2001

[Viral respiratory infections as cause of fever in hospitalized aged patients during a winter season].

PURPOSE: In the geriatric units of the University Hospital of Saint-Etienne, 129 cases of fever (38 degrees C or more) were recorded prospectively during the 1995-1996 winter period in a population of 503 hospitalised patients (25.6%), and were investigated for the detection of a viral aetiology. METHODS: In febrile patients, a standard form was used to record clinical and biological parameters, including the results of investigations for respiratory viruses from a nasal swab and dual serum specimens. RESULTS: A clinical or radiological respiratory infection was found in 69 cases (53.5% of all cases of fever), including 14 respiratory syncytial virus (RSV) infections. In comparison to nonviral respiratory infections, the RSV infections were characterised by the prevalence of anorexia (57% vs 20%, P < 0.05) and rhinorrhea (64% vs 5%, P < 0.01). No influenza infection was recorded despite the concomitant circulation of influenza virus in the community. A nosocomial outbreak of RSV infection (nine cases, attack rate of 18.7%) was identified in a long-stay care unit. CONCLUSION: This study illustrates the high prevalence (10.9%) of RSV infections in elderly patients with fever during this season and the importance of hygienic measures to control the spread of nosocomial outbreaks.

Age Factors↗
PubMed2001

Nosocomial colonization of premature babies with Klebsiella oxytoca: probable role of enteral feeding procedure in transmission and control of the outbreak with the use of gloves.

OBJECTIVE: To investigate the persistence of colonization of premature babies by Klebsiella oxytoca, with special emphasis on the mode of transmission of the bacterium and evaluation of Standard Precautions to stop the epidemic. DESIGN: Retrospective analysis of cases and prospective study of systematic bacteriological samples (stools and throat) from babies, healthcare workers (HCWs), and environment, with genotyping of strains by arbitrarily primed polymerase chain reaction. SETTING: A premature baby unit (PBU) and a neonatal intensive care unit in the university hospital of Saint-Etienne, France. RESULTS: An outbreak of K oxytoca was suspected in two pediatric wards after the occurrence of a fatal bacteremia in a newborn hospitalized in the PBU and the colonization of other babies 2 months later. Retrospective analysis showed that 24 babies' digestive tract had been colonized. No environmental reservoir was recovered in the units nor in enteral feeding. No K oxytoca was isolated from HCW samples. Genotyping confirmed the presence of epidemic strains, although independent clones were responsible for infections or colonizations in each of the two units. The chronology and the site of babies' colonization (isolation of K oxytoca in stools before throat) were determined during a prospective study and suggested that enteral feeding procedures could be the source of contamination. Therefore, use of gloves during this practice by HCWs was recommended and, after readjustment of Standard Precautions, stopped the outbreak. CONCLUSION: To prevent cross-contamination among high-risk babies, careful attention must be paid to Standard Precautions. Bacteriological surveillance of the digestive tract of neonates could help to check compliance with these guidelines

Disease Outbreaks↗
PubMed2000

Neutralization of human immunodeficiency virus type 1 (HIV-1) mediated by parotid IgA of HIV-1-infected patients.

Infection with human immunodeficiency virus type 1 (HIV-1) has been shown to elicit a serum antibody response with neutralizing activity against T cell line-adapted HIV strains and primary HIV-1 isolates. Mucosal surfaces are the primary route of HIV-1 infection. Evidence is presented here for the presence of HIV-neutralizing antibodies in secretions. Infection of mucosal cells with HIV stimulates systemic and mucosal immune responses and results in the generation of neutralizing antibodies. Serum IgG and IgA neutralize HIV-1MN infection of susceptible T cell lines; serum IgG inhibits more effectively. Mucosal IgA purified from parotid saliva of HIV-1-seropositive individuals could neutralize both a T cell line-adapted strain and a primary isolate. The neutralizing activity of IgA was not directed against the anti-third-variable-loop or the anti-ELDKWA epitope. Thus, the specificity of mucosal IgA for HIV-1 neutralization epitopes remains to be determined and may provide insight into development of a mucosal vaccine.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Enteroviral capsid protein VP1 is present in myocardial tissues from some patients with myocarditis or dilated cardiomyopathy.

BACKGROUND: There are still discrepancies in the association of enterovirus and myocardial disease, partially due to lack of data on the detection of virus antigens in tissues. It is desirable to localize enteroviral antigens so as to establish a link between the two and to study mechanisms of virus persistence. METHODS AND RESULTS: Nineteen fixed explanted or postmortem myocardial samples were obtained from patients with myocarditis or dilated cardiomyopathy (DCM). Control samples were collected from 11 subjects who had died accidentally or of noncardiovascular disease. Viral antigen was detected by an improved immunohistochemical technique using an enterovirus group-specific antibody to viral capsid protein VP1. Nine of 11 myocarditis cases (81.8%) and 6 of 8 DCM cases (75%) were positive. Signals were localized in the cytoplasm of myocytes. Intense immunostaining was observed in acute myocarditis, whereas VP1 was detected in scattered myocytes in chronic myocarditis or DCM. Enteroviral RNA was detected in 6 of 11 myocarditis samples (54.5%) and 3 of 8 DCM samples (37.5%) by the reverse transcription-nested polymerase chain reaction, correlating with antigen detection (kappa=0.6+/-0.21). Neither viral antigen nor RNA was detected in any controls. CONCLUSIONS: Our findings demonstrate a direct link between enterovirus infection and some myocarditis or DCM cases. The pattern of VP1 detection may correlate with disease stage and severity. The data suggest that viral protein synthesis may be involved in persistent enterovirus infection in the pathogenesis of DCM.

Adolescent↗
PubMed1999

[Prospective comparative study of HCV serologic status in and AIDS population].

OBJECTIVE: Study the influence of hepatitis C virus (HCV) serology on the course of HIV disease in AIDS patients. PATIENTS AND METHODS: A prospective study of survival prognosis in HIV infected patients who had reached the AIDS stage was conducted in the Saint-Etienne, Clermond-Ferrand and Lyons infectious disease centers to compare patients with positive and negative HCV serology. Data were collected using the clinico-epidemiological software DMI II. The effect of HCV ìco-infectionî defined by RIBA II or III confirmed seropositivity, was studied using Kaplan-Meier survival plots. RESULTS: Among the 1,005 HIV-infected subjects included in the study, 219 had AIDS and 43 of them (19.6%) were HCV positive. Survival curves in HIV/HCV positive patients with AIDS were not significantly different from those of HCV-negative AIDS patients (median 17.8 versus 18.6 months respectively, p = 0.93). This result was confirmed by univariate Kaplan-Meier analysis. Only 2 patients were treated with interferon and no deaths were attributed to liver disease. CONCLUSION: HCV positivity in AIDS patients does not appear to influence survival. The longer survival obtained with the new anti-retroviral treatments may have an effect on the HIV-HCV interaction.

AIDS-Related Opportunistic Infections↗
PubMed1999

Variations in the recognition of echovirus type 11 strains by a group-specific anti-VP1 monoclonal antibody.

BACKGROUND: Mab 5-D8/1 is a monoclonal antibody (Mab) that was shown to be directed towards a conserved epitope of the capsid protein VP1 among the genus enterovirus. The use of this Mab for the routine detection of enteroviruses in clinical specimens led to the observation that several strains of echovirus type 11 (EV-11) could not be detected on spontaneously detached cells from 26-h cultures using a two-step immunofluorescence (IF) assay. Conversely, these strains were detected positive with the same Mab when tested on adherent or trypsinizated cells. OBJECTIVES: The aim of this study was to understand the misrecognition of some strains of EV-11 by this Mab. STUDY DESIGN AND RESULTS: IF tests at different times of the viral cycle brought evidence that the detection of a variant strain of EV-11 decreased rapidly with time, becoming undetectable 26 h post-infection, since the reference strain remained positive up to 46 h post-infection. The infective titres of the variant strains were shown to be high in comparison with those of well-recognised strains. Sequencing the Mab binding epitope confirmed that the variant strains exhibited no antigenic shift. CONCLUSION: These results suggest that the poor recognition of some strains of EV-11 by Mab 5-D8/1 is due to a rapid decrease of the expression of the binding epitope in the cell, maybe in relation with the high lytic power of these strains. From a practical point of view, our data indicate that a negative result when Mab 5-D8/1 is used for enterovirus typing must be interpreted cautiously with highly replicative strains and that detached cells should not be used for enterovirus identification under these circumstances.

Antibodies, Monoclonal↗
PubMed1999

Investigation of a nosocomial outbreak due to Serratia marcescens in a maternity hospital.

OBJECTIVES: To investigate an outbreak of Serratia marcescens in a maternity hospital (November 1994 to May 1995). DESIGN: Retrospective analysis of epidemiological data and prospective study of systematic bacteriological samples from patients and environment, with genotyping of strains by arbitrarily primed polymerase chain reaction. SETTING: A private maternity hospital, Saint-Etienne, France. RESULTS: In the neonatal unit, 1 newborn developed a bacteremia, and 36 were colonized in stools with S marcescens. As the colonization of some newborns was shown to occur only a few hours after delivery, the inquiry was extended to other maternity wards, where 8 babies and 4 mothers were found to be colonized. Environmental sampling led to the isolation of S marcescens from a bottle of enteral feed additive in the neonatal unit and from the transducers of two internal tocographs in the delivery rooms. The genotyping of 27 strains showed two different profiles: a major epidemic profile shared by 22 strains (18 from babies of the neonatal unit, 2 from babies of other units, and 2 from breast milk) and another profile shared by 5 strains (2 from transducers of internal tocographs, 2 from babies, and 1 from a mother). The strain isolated from lipid enteral feeding was not available for typing. Although this source of contamination was removed soon from the neonatal unit, the outbreak stopped only when infection control measures were reinforced in the delivery rooms, including the nonreuse of internal tocographs. CONCLUSIONS: In delivery rooms, the quality of hygiene needs to be as high as in surgery rooms to prevent nosocomial colonization or infection of neonates at birth.

Cross Infection↗
PubMed1999

High sensitivity and specificity of serum procalcitonin levels in adults with bacterial meningitis.

It was shown in children that serum procalcitonin was the best marker to use to differentiate bacterial from viral meningitis. To evaluate procalcitonin in the diagnosis of acute bacterial and viral meningitis, we conducted a prospective study including adult patients who were suspected of having meningitis and who were admitted to an emergency department. Cerebrospinal fluid (CSF) and serum levels of procalcitonin were measured in 105 consecutive patients. The diagnosis of meningitis was based on clinical findings, gram staining, culture, and chemical analysis of CSF. Twenty-three patients had bacterial meningitis, 57 had viral meningitis, and 25 did not have meningitis. Bacteriologic and chemical analysis of CSF did not allow correct differentiation of viral from bacterial meningitis. On the other hand, a serum procalcitonin level >0.2 ng/mL had a sensitivity and specificity of up to 100% in the diagnosis of bacterial meningitis. Serum procalcitonin levels seem to be the best marker in differentiating between bacterial and viral meningitis in adults.

Adolescent↗
PubMed1999

Prevalence of GBV-C/hepatitis G virus RNA and E2 antibody among subjects infected with human immunodeficiency virus type 1 after parenteral or sexual exposure.

GB virus C (GBV-C) or hepatitis G virus (HGV) is transmitted by the parenteral route but the importance of sexual transmission needs to be ascertained. GBV-C/HGV infections were investigated using RNA and E2-antibody detection methods in 80 subjects infected by the human immunodeficiency virus type 1 (HIV-1) divided into 4 groups of 20 individuals each according to their main risk factor for HIV-1 infection: blood product recipients (group 1), intravenous drug users (group 2), homosexuals (group 3), or heterosexual exposure (group 4). The overall prevalence of GBV-C/HGV infection was 66.3%. No significant difference was observed in GBV-C/ HGV prevalence among the four groups: 75, 75, 55, and 60% in groups 1, 2, 3, and 4, respectively. Hepatitis C virus (HCV) antibodies, used as a control for parenteral exposure, were found in 70% and 90% of the subjects in groups 1 and 2 versus only 15% and 20% of the subjects in groups 3 and 4, respectively (P< .001). Similarly, coinfections with GBV-C/HGV and HCV were significantly associated with the parenteral route (P <.001). These data emphasized the usefulness of combining the detection of RNA and the E2 antibody to determine the actual prevalence of GBV-C/HGV infection. The high prevalence of the GBV-C/HGV markers among the HIV-1-infected subjects, especially those with sexual exposure, provides additional evidence that this route of transmission plays a key role in the epidemiology of GBV-C/HGV. The potential influence of GBV-C/HGV infection on the course of HIV-1 disease needs further evaluation.

Adult↗
PubMed1998

[Influenza].

Explore the source record for details and available documents.

Antiviral Agents↗