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J Petitjean

Publications and source records attributed to J Petitjean.

At least 19 recordsLinked to original sources
PubMed2005

Development and evaluation of a real-time RT-PCR assay on the LightCycler for the rapid detection of enterovirus in cerebrospinal fluid specimens.

BACKGROUND: Detection of enteroviral nucleic acid in cerebrospinal fluid (CSF) specimens has been demonstrated to improve the management of patients with aseptic meningitis. OBJECTIVE: To develop on the LightCycler (LC) instrument a real-time RT-PCR assay based on TaqMan technology for the detection of enteroviruses (EV) in cerebrospinal fluid (CSF) specimens. STUDY DESIGN: After evaluation of the analytical performances, seventy-four CSF samples collected prospectively from patients who have been suspected for a clinical diagnosis of meningitis were evaluated by two LC real-time RT-PCR assays and one conventional RT-PCR assay. RESULTS: Our assay detected all 30 different EV species tested, whereas no reactivity was observed with other neurotropic viruses. The analytical sensitivity of both LC RT-PCR real-time assays was 1 TCID50 for LC one-step and two-step RT-PCR assays. Results for LC one-step and LC two-step RT-PCR were compared to results of the conventional RT-PCR: of the 74 CSF specimens tested, 11 were positive and 56 were negative by all methods. Four other specimens were positive for EV by at least two of the methods (including the LC two-step RT-PCR and the conventional RT-PCR), two other CSF specimens were positive by the LC two-step RT-PCR assay only, and another one CSF specimen was positive by the LC one-step RT-PCR assay only. No CSF specimens were negative by the LC two-step RT-PCR assay and positive by the conventional RT-PCR assay. The sensitivity, specificity, positive and negative predictive values of both LC RT-PCR assays by using conventional RT-PCR as the "gold standard" were, respectively, 73.3, 98.3, 91.7, 93.5% for the LC one-step RT-PCR and 100, 96.6, 88.2, 100% for the LC two-step RT-PCR. There was substantial agreement between the three assays (k=0.80). CONCLUSIONS: The LC two-step RT-PCR assay is a rapid, sensitive and reliable method which can be routinely performed with CSF samples for diagnosis of EV infection and is an important improvement for optimal patient management.

Cerebrospinal Fluid↗
PubMed2004

[Epidemiology and diagnosis of respiratory syncitial virus in adults].

INTRODUCTION: Respiratory syncytial virus (RSV) is rarely searched for in respiratory infections in adults. This study assessed its frequency and diagnosis. METHODS: Three separate studies were conducted in adults presenting with (1) a flu-like illness, (2) a lower respiratory tract infection in the community, and (3) a severe pneumonia requiring hospitalisation. The diagnosis of RSV infection was sought by PCR in all cases, and compared to antigen detection and culture in two studies. RESULTS: RSV was identified in 20 (11.7%) of 170 influenza-vaccinated adults suffering from flu-like symptoms. In the 270 cases of non-severe lower respiratory tract illnesses in the community, viruses were identified in 86 (31.8%) cases, with RSV accounting for 13 (4.8%). In the 164 cases of acute bronchitis, a virus was detected in 64 (36.7%) of which 11 (6.3%) were RSV, 37 (21.3%) rhinovirus, 5 influenza viruses A and B, and 12 other viruses. In the 60 cases of infective exacerbations of chronic bronchitis, rhinovirus was detected in 9 (15%) and para-influenza 3 virus in 2 cases. In the 21 acute pneumonia's, 1 RSV, 1 influenza virus A and 2 rhinovirus cases were detected as well as 1 RSV, 1 parainfluenza 3 viruses and 4 rhinovirus cases in the 11 lower respiratory tract illnesses in patients with pre-existing lung disease. There were overall 19 viral and bacterial associated infections. Finally, in the 51 acute pneumonias hospitalised with respiratory distress syndrome, a virus was identified in 17 (33.3%) cases, including 3 (5.5%) RSV, 6 influenza A, 3 rhinovirus, 2 adenovirus, 2 herpes simplex virus and 1 cytomegalovirus. There were 6 bacterial-associated infections, and 4 were hospital-acquired. All RSV-infected patients were old people and had chronic pulmonary or cardiac disease. CONCLUSIONS: In adults, RSV is a frequent cause of flu-like symptoms. It can sometimes cause lower respiratory tract illness, which can be severe, and should be considered in the differential diagnosis in such cases. The PCR method is a particularly effective diagnostic test, but as yet is not routinely available.

Adult↗
PubMed2004

Quantitative analysis of HCMV DNA load in whole blood of renal transplant patients using real-time PCR assay.

BACKGROUND: Preemptive antiviral treatment of Human Cytomegalovirus (HCMV) disease is a major goal in the management of organ transplant patients. It requires sensitive diagnostic methods. Automated real-time PCR systems have been recently proposed to monitor HCMV infection in such patients. OBJECTIVE: Objectives of this study was to compare a real-time quantitative PCR on whole blood with the HCMV pp65 antigenemia assay in renal transplant recipients, and also to evaluate two different DNA extraction methods. STUDY DESIGN: A total of 248 specimens from 21 patients were tested by quantitative pp65 antigenemia and quantitative real-time PCR. DNA was extracted from whole blood samples using two different methods: a conventional column manual assay and an automated system. RESULTS: Quantification of HCMV DNA using the two extraction methods showed highly similar results (Spearman rank test, r=0.863). We found a significant correlation between DNA quantification by real-time PCR in whole blood and pp65 antigenemia test (Spearman rank test, r=0.767). This correlation was not modified when the HCMV DNA results were normalized by quantification of the albumin cellular gene. In eight patients, HCMV infection was detected earlier with quantitative PCR than with the antigenemia test (mean delay of 11.25 days). HCMV DNA load equivalent of 50 pp65 positive cells/200,000 polymorphonuclear leukocytes (PMNLs) is log4.095 copies per ml of blood. CONCLUSIONS: Real-time PCR in whole blood is a sensitive method for estimating the HCMV genome load in renal transplant patients, and is more rapid and practicable than using PMNLs for pp65 antigenemia tests.

Cytomegalovirus↗
PubMed2003

Quantitation of respiratory syncytial virus RNA in nasal aspirates of children by real-time RT-PCR assay.

A method was developed for the quantitation of respiratory syncytial virus (RSV) based on real-time RT-PCR using a LightCycler instrument. A control real-time RT-PCR was undertaken on GAPDH mRNA (a human housekeeping gene) was carried out to standardise the non-homogeneous respiratory samples. The real-time RT-PCR method was one log more sensitive for the detection of RSV according to the endpoint dilution technique than the culture method or a conventional qualitative RT-PCR-hybridization-EIA. No cross-reactivity was observed with any of the viruses that could be found in the respiratory tract. RSV and GAPDH were quantified in nasal aspirates from 75 children hospitalised for acute respiratory tract disease: 31 (41.3%) were positive according to the immunofluorescence assay (IFA), 34 (45.3%) were culture-positive and 42 (56%) were positive according to our real-time RT-PCR method. The sensitivity, specificity, positive and negative predictive values of the real-time RT-PCR were 100, 90, 92, 100%, respectively. The samples found to be positive for RSV were classified according to the severity of the disease. The mean number of RSV RNA copies was higher in the severe disease group than in the non-severe group 4.05 x 10(7) vs 9.1 x 10(6) (P=0.055). However, the mean ratio of RSV RNA copies to GAPDH mRNA copies was 42.8 in the severe group, and 22.2 in non-severe group (P=NS).

Acute Disease↗
PubMed2002

[Evaluation of four commercial immunoglobulin G (IgG)- and IgM- specific enzyme immunoassays for diagnosis of Mycoplasma pneumoniae infections].

The four following commercially available enzyme immunoassays (EIAs) were assessed and compared for their performance in detecting Mycoplasma pneumoniae specific IgG and IgM antibodies: EIA-Platelia, EIA-Bmd, EIA-Sorin and EIA-Biotest. Three groups of patients were investigated: 39 patients (27 children and 12 adults) with respiratory infections and a M. pneumoniae PCR-positive in respiratory specimens (group I; 52 sera), 61 healthy children and adults (group II; 61 sera) and 20 patients with rheumatoid factor, antinuclear antibodies or positive antiviral IgM (group III; 20 sera). In group III, the IgM specificity for the EIA-Platelia, EIA-Bmd, EIA-Biotest and EIA-Sorin was 100%, 90%, 65% and 25%, respectively. In the children from group I, the four EIAs had similar IgM sensitivity (89 to 92%) but a striking difference in IgM sensitivity was observed in adult patients: 16% EIA-Platelia and EIA-Bmd, 50% EIA-Biotest, 58% EIA-Sorin. The sensitivity for IgG was greater with EIA-Bmd and EIA-Biotest, especially in detection of IgG in acute-phase serum : 61% EIA-Bmd and EIA-Biotest, 15% EIA-Platelia and 31% EIA-Sorin. Discrepant and unexpected results were observed in IgM detection from control healthy patients using EIA-Sorin and EIA-Biotest, confirming the lack of specificity of these two EIA-tests and making them inaccurate for routine diagnosis. A high IgG seroprevalence were found in healthy adults by the four EIAs (43-70%). In healthy children, EIA-Bmd and EIA-Biotest gave a higher IgG seroprevalence than EIA-Sorin and EIA-Platelia (45% each for the former as compared to 17% and 20%, respectively, for the latter).These results confirm that the IgM EIA serology test is a valuable tool for the early diagnosis of M. pneumoniae infections in children, as long as the EIA test used is specific. In adults, the difficult interpretation of EIA tests suggests that paired sera, combined with PCR detection on respiratory tract specimens collected on admission of patient, should be required for accurate diagnosis.

Adult↗
PubMed2002

[Role of viral infections and Chlamydia pneumoniae and Mycoplasma pneumoniae infections in asthma in infants and young children. Epidemiologic study of 118 children].

Wheezing associated with upper respiratory tract infections is common in children. Using conventional techniques (viral culture and immunofluorescence) and molecular techniques (PCR), we studied the prevalence of viral, Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP) infections in 118 children hospitalised for acute asthma exacerbation. A virus was identified by conventional techniques in 40 of the 118 nasal swabs (34%), while PCR allowed identification of virus CP and MP in 80 samples (68%). Combination of both techniques allowed identification of an infectious agent in 91 cases (77%). More than one agent was isolated in 15 cases (23%). Rhinovirus (RV) (45%) were prevalent, followed by respiratory syncytial virus (RSV) (28%) and enterovirus (8.5%). RV and RSV have a similar prevalence (42% and 36% respectively) before two years of age, as compared with 66% and 27% respectively in older children. CP and MP were identified by PCR in only 6 cases. Molecular techniques of identification demonstrated a clear advantage in sensitivity compared with conventional techniques. The high prevalence of RV and RSV infections is remarkable, while CP and MP do not seem particularly involved in children acute asthma exacerbation.

Asthma↗
PubMed2002

Evaluation of four commercial immunoglobulin G (IgG)- and IgM-specific enzyme immunoassays for diagnosis of Mycoplasma pneumoniae infections.

The four following commercially available enzyme immunoassays (EIAs) were assessed and compared for their performance in detecting Mycoplasma pneumoniae immunoglobulin G (IgG)- and IgM-specific antibodies Platelia EIA, ImmunoWELL M. pneumoniae ELISA IgG and IgM, ETI-MP-IgG and IgM EIAs and Biotest anti-M. pneumoniae IgG and IgM ELISA (referred to herein as EIA-Platelia, EIA-BMD, EIA-Sorin, and EIA-Biotest). Three groups of patients were investigated: 39 patients (27 children and 12 adults) with respiratory infections who tested positive by PCR for M. pneumoniae in respiratory specimens (group I; 52 serum samples), 61 healthy children and adults (group II; 61 serum samples), and 20 patients with rheumatoid factor or antinuclear antibodies, or who tested positive for antiviral IgM (group III; 20 serum samples). In group III, the IgM specificity for EIA-Platelia, EIA-BMD, EIA-Biotest, and EIA-Sorin was 100, 90, 65, and 25%, respectively. In the children from group I, the four EIAs had similar IgM sensitivities (89 to 92%); the sensitivity for IgG was greater with EIA-BMD and EIA-Biotest than with EIA-Platelia and EIA-Sorin (66 and 78% versus 55 and 52%, respectively). In adult patients from group I, 9 to 10 serum samples were positive for IgG with a concordant sensitivity of 75 to 83% between the four EIAs but a striking difference in IgM sensitivity: 16% by EIA-Platelia and EIA-BMD, 50% by EIA-Biotest, and 58% by EIA-Sorin. Discrepant and unexpected results were observed in IgM detection from control healthy patients using EIA-Sorin and EIA-Biotest, confirming the lack of specificity of these two EIAs and making them inaccurate for routine diagnosis. A good concordance of IgG seroprevalence in healthy adults was found between the four EIAs (66 to 70%), though this concordance was lower with EIA-Platelia (43%). In healthy children, EIA-BMD and EIA-Biotest gave a higher IgG seroprevalence than EIA-Sorin and EIA-Platelia (45% each for the former compared to 17 and 20%, respectively, for the latter). These results confirm that the IgM EIA serology test is a valuable tool for the early diagnosis of M. pneumoniae infections in children, as long as the EIA used is specific. In adults, the difficult interpretation of EIAs suggests that paired sera, combined with PCR detection on respiratory tract specimens collected on admission of patient, should be required for accurate diagnosis.

Adult↗
PubMed2001

Direct diagnosis of human respiratory coronaviruses 229E and OC43 by the polymerase chain reaction.

An RT-PCR-hybridization was developed that amplified genetic material from the M protein gene of HCoV-229E and HCoV-OC43. The analytic sensitivity of these original primers were compared with primers defined in the N gene and described previously. The results show that 0.05 TCID50 of HCoV-229E and 0.01 TCID50 of HCoV-OC43 can be detected by this molecular method using the original method. Detection of HCoV-229E and HCoV-OC43 in clinical specimens is possible using this method: 348 respiratory specimens (202 sputum and 146 nasal aspirates) were tested with this RT-PCR-hybridization and 12 human coronavirus are detected (3%). The method could provide a useful tool for demonstrating the role of human coronavirus in infections of the respiratory tract.

Cell Line↗
PubMed2001

[Epidemiology of respiratory virus infections].

Respiratory viral infections are very common in young children. They sometimes occur as primary infections (and sometimes re-infections) by influenza and parainfluenza virus, respiratory syncytial virus (VRS), adenovirus, rhinovirus and coronavirus. The clinical pictures are very varied and without strict clinico-virological correlation. In adults the role of the site (frail lung, aged persons) and the type of virus play an important part. Many viral infections develop in an epidemiological way (influenza, VRS bronchiolitis, rhinovirus infections...) and several epidemics by different viruses overlap from September-October to March-April making it very difficult to decide the precise cause. Epidemics are followed thanks to networks of medical practitioners (GROG, SENTINELLE...) and by data from hospitalised patients, but precise identification of epidemic viruses is only possible and validated by virological analysis of samples taken from patients.

Adenoviridae Infections↗
PubMed2000

Comparison of three non-nested RT-PCR for the detection of influenza A viruses.

BACKGROUND: The viral isolation technique (VIT) is largely used as a gold standard for the detection of influenza A and B viruses in respiratory samples. Some recent studies have pointed out that the polymerase chain reaction (PCR) assays allow sensitive and rapid detection of influenza viruses, also providing excellent correlation with traditional methods. OBJECTIVES AND DESIGN STUDY: The aim of this study was to evaluate the efficiency of three non-nested PCR, two PCR-hybridization assays using primers defined in M and NS genes, and one PCR which uses primers defined in NP, NS and HA genes and combines the detection of H3N2 and H1N1 hemagglutinin genes using defined primers in NP, NS and HA genes (PCR3), in comparison with an IF assay (IFA) and viral isolation technique (VIT). The study was carried out on 244 nasal samples collected mainly by practitioners of the GROG surveillance network during winter 1998-1999 for the detection of influenza A virus. RESULTS: Overall influenza viruses were detected more frequently by PCR techniques in 157 (64.3%), 147 (60.2%), 110 (45%) cases for PCR1, PCR2, PCR3, respectively, than by VIT or IFA, in 100 (40.9%) and 74 (30.3%) cases, respectively. Taking the positive culture samples as a reference, 100 (41.8%) samples were found to be positive for influenza A, and the sensitivity of IFA, PCR 1, PCR 2 and PCR3 techniques were 70, 100, 99, and 90%, respectively as compared with viral isolation cultures. On the other hand, as 86.5% of positive samples were positive with at least two different techniques, the sensitivity, specificity, VPP and VPN of each technique were recalculated taking into account a further criterion defining a positive sample: positivity with two techniques. We observe that techniques PCR 2 and particularly PCR 1 have very good sensitivity, respectively 98.6 and 100%, far better than the traditional techniques, IFA and culture, whilst maintaining acceptable specificity: 94.1 and 86.1%, respectively. In both cases they enable 141 (57.7%) A-positive influenza samples to be detected instead of the 100 (40.9%) obtained when culture is the reference test. IFA, culture and PCR 3 are highly specific (VPP=100%), but in comparison with PCR 1 and 2 their sensitivity, respectively 51.7, 69. 9, 77.6%, and negative predictive value are unsatisfactory. PCR 1 and 2 are superior to the other techniques to a statistically highly significant degree in terms of sensitivity, but the difference between the two is not significant.

Adolescent↗
PubMed1999

Detection of viral, Chlamydia pneumoniae and Mycoplasma pneumoniae infections in exacerbations of asthma in children.

BACKGROUND: A high frequency of virus infections has been recently pointed out in the exacerbations of asthma in children. OBJECTIVES: To confirm this, using conventional and molecular detection methods, and expanding the study to younger children. STUDY DESIGN: One hundred and thirty-two nasal aspirates from 75 children hospitalized for a severe attack of asthma were studied (32 infants, mean age 9.1 months; and 43 children, mean age 5.6 years). According to the virus, a viral isolation technique, immunofluorescence assays (IFA) or both were used for the detection of rhinovirus, enterovirus, respiratory syncytial (RS) virus, adenovirus, coronavirus 229E, influenza and parainfluenza virus. Polymerase chain reaction (PCR) assays were used for the detection of rhinovirus, enterovirus, RS virus, adenovirus, coronavirus 229E and OC43, Chlamydia pneumoniae and Mycoplasma pneumoniae. RESULTS: Using IFA and viral isolation techniques, viruses were detected in 33.3% of cases, and by PCR techniques, nucleic acid sequences of virus, Chlamydia pneumoniae and Mycoplasma pneumoniae were obtained in 71.9% of cases. The combination of conventional and molecular techniques detects 81.8% of positive samples. Two organisms were identified in the same nasal sample in 20.4% of the cases. The percentage of detections was higher (85.9%) in the younger group than in the other (77%). The most frequently detected agents were rhinovirus (46.9%) and RS virus (21.2%). Using PCR rather than conventional techniques, the detection rates were increased 5.8- and 1.6-fold in rhinovirus and RS virus infections, respectively. The detection levels of the other organisms are as follows: 9.8, 5.1, 4.5, 4.5, 4.5, 3.7, and 2.2% for enterovirus, influenza virus, Chlamydia pneumoniae, adenovirus, coronavirus, parainfluenza virus, and Mycoplasma pneumoniae, respectively. CONCLUSION: These results confirm the previously reported high frequency of rhinovirus detection in asthmatic exacerbations in children. They also point out the frequency of RS virus detection, and emphasize the fact that PCR assays may be necessary to diagnose respiratory infections in asthma.

Adolescent↗
PubMed1999

[Acute respiratory Chlamydia pneumoniae infections in adults. Value of direct gene amplification diagnosis].

Chlamydia pneumoniae has been established recently as an important human respiratory pathogen. The aim of this study was to define the incidence of Chlamydia pneumoniae in acute respiratory infections by evaluating its presence in posterior nasopharyngeal aspirates or broncho-alveolar lavage specimens by polymerase chain reaction-hybridization (PCR-EIA) as well as the titres of specific antibodies in serum by a rELISA test and a micro-immunofluorescence (MIF) test. 68 adults patients were investigated. Eight patients (11.8%) were positive by either rELISA or PCR-EIA or both, with an infection rate of 5 patients with community-acquired pneumonia, 2 asthmatic patients and 1 patients with an exacerbation of chronic obstructive pulmonary disease. Serological evidence of acute infection was found in four of these patients with rELISA test and in three others with MIF test. PCR-EIA detected Chlamydia pneumoniae DNA in four patients, but there were concordant results with rELISA and PCR-EIA in only one patient. In conclusion, Chlamydia pneumoniae appears to be a common etiologic agent of acute respiratory infections in adults. The discrepancy between serological test and PCR-EIA results reflects the difficulties in routine laboratory diagnosis of Chlamydia pneumoniae. The ambiguous results of serological tests from a single serum sample assess the utility of PCR for prompt diagnosis. When PCR is negative or no feasible, a second serology to 15/21 days of interval is necessary. Further studies with optimised techniques must be developed.

Acute Disease↗
PubMed1998

[Human coronavirus infections: importance and diagnosis].

POORLY-KNOWN VIRUS: Coronaviruses, so named because of their sun-ray-like aspect, were discovered in the sixties. The biology of these RNA viruses is complex and poorly understood. KNOWN PATHOGENS: Coronaviruses are known pathogens in veterinary medicine, causing disease states in several domestic species. In human medicine, they can cause benign respiratory infections, but few laboratories include coronaviruses in their routine diagnostic tests. SUSPECTED PATHOGENS: There is some data in the literature suggesting coronaviruses might be implicated in more severe diseases including multiple sclerosis, necrotizing enterocolitis, and lower respiratory tract infections, particularly in infants. IMPROVING DIAGNOSTIC METHODS: Due to the lack of reliable and sensitive diagnostic techniques, it is impossible to date to correctly assess the medical impact of these ubiquitous and endemic viruses. Molecular biology techniques enabling detection of human coronavirus infections should be applied to verifying the suspected implication of these viruses in diverse disease states.

Animals↗
PubMed1998

Comparison of two serological methods and a polymerase chain reaction-enzyme immunoassay for the diagnosis of acute respiratory infections with Chlamydia pneumoniae in adults.

Chlamydia pneumoniae is a common respiratory tract pathogen. Serological methods currently used for the diagnosis of C. pneumoniae infection lack specificity, give ambiguous results from a single serum sample and often provide only a retrospective diagnosis. A prospective study was undertaken to assess whether PCR could be a useful addition to the serological techniques routinely practised for diagnosis. This study investigated 68 adult patients with a diagnosis of acute respiratory infection. Acute and convalescent serological determination of antibodies to C. pneumoniae were performed by means of an rELISA test and a micro-immunofluorescence (MIF) test. Nasopharyngeal aspirates or bronchoalveolar lavage specimens and bronchial aspirates obtained from the 68 patients were evaluated by PCR-enzyme immunoassay (PCR-EIA) for the presence of C. pneumoniae and by immunofluorescence assay and cell culture for virus identification. Mycoplasma pneumoniae serology was also performed. Eight patients (11.8%) were positive by either rELISA or PCR-EIA, or both, with an infection rate of 5 (18.5%) of 27 in patients with community-acquired pneumonia, 2 (9%) of 22 in asthmatic patients and 1 (5%) of 19 in patients with an exacerbation of chronic obstructive pulmonary disease. Serological evidence of acute infection was found in four of these patients with the rELISA test and in three others with the MIF test. PCR-EIA detected C. pneumoniae DNA in four specimens, but there were concordant results with both rELISA and PCR-EIA in only one patient A positive PCR-EIA was also obtained in a patient who did not show an antibody response in acute serum. The discrepancy between serological and PCR-EIA results reflects the difficulties in routine laboratory diagnosis of C. pneumoniae infection and the necessity for further studies with optimised techniques.

Acute Disease↗
PubMed1997

Detection of respiratory syncytial virus, parainfluenzavirus 3, adenovirus and rhinovirus sequences in respiratory tract of infants by polymerase chain reaction and hybridization.

BACKGROUND: Immunofluorescence assay (IFA) of viral antigens in nasal aspirates is largely used for the diagnosis of respiratory syncytial virus (RSV), parainfluenzavirus (PIV) type 3 and adenovirus (AdV) infections, whilst rhinovirus (RV) are detected by virus isolation technique (VIT) only. Using the two techniques, IFA and VIT, a significant number of specimens remain negative in spite of clinical and epidemiological presumptions of viral infection. OBJECTIVES AND STUDY DESIGN: The polymerase chain reaction (PCR) should improve the sensitivity of viral detection in clinical specimens. From October 1995 to March 1996, 277 nasal aspirates from hospitalized infants were tested simultaneously by IFA, VIT, polymerase chain reaction and hybridization with a DNA enzyme immunoassay (PCR-EIA) for RSV, PIV-3, AdV and RV. RESULTS: RSV were detected in 177 (64%) samples, PIV-3 in 23 (8%), RV in 40 (14%), and AdV in 30 (10%). PCR-EIA detected RSV in more samples 173 (62%) than IFA/VIT: 109 (39%) (P < 10(-7)). In most cases (79%), RSV-infected infants had lower respiratory tract disease, and routine and PCR techniques were positive. Out of the 23 PIV-3 infections, 12 were IFA/VIT- and PCR-EIA-positive, and 11 IFA/VIT-negative and PCR-EIA-positive. For RV, 35 (87%) specimens were PCR EIA-positive and 11 (27%) culture-positive; for AdV 30 samples were PCR-EIA-positive and four were culture-positive. Simultaneous viral infections were revealed in a significantly higher proportion than in conventional techniques: 18% (50/277) versus 2.5% (7/277); P < 10(-7). One RSV infection in four was associated with the presence of another virus, mainly PIV-3 (16 cases) and AdV (13 cases). CONCLUSIONS: PCR-EIA detects more positive-specimens than IFA/VIT, 1.5 times more for RSV, 1.9 for PIV-3, 4 for RV and 10 for AdV, respectively. This increased sensitivity of viral detection by PCR-EIA compared to the IFA/VIT could suggest that samples containing low levels of virus are missed by routine methods IFA/VIT, and consequently, RSV or PIV-3, and above all RV or AdV are overlooked as agents of respiratory diseases. However, apart from the fact that the economic and convenient aspects of virus diagnostic cannot be missed, it is difficult to answer the following questions: what is the meaning of the detection of a viral sequences in nasal aspirates of infants, or may PCR have detected virus in patients who would not developed disease?

Adenoviridae↗
PubMed1996

Multicenter evaluating of a commercially available PCR assay for diagnosing enterovirus infection in a panel of cerebrospinal fluid specimens.

Thirteen laboratories participated in blind tests of a panel of 20 coded cerebrospinal fluid specimens (7 uninfected samples, 3 samples infected with 1 50% tissue culture infective dose [TCID50]/0.1 ml [nonenterovirus strains], and 10 samples infected with 10, 1, or 0.1 TCID50/0.1 ml [three different enterovirus serotypes]) on the Amplicor enterovirus PCR assay (Roche Diagnostic Systems). The panel was also evaluated by in-house PCR (two nested-PCR and three one-step PCR assay) or tissue culture (eight laboratories). The viral load was shown to influence greatly the sensitivity of the assay. The average sensitivity of the Amplicor test ranged from 67 to 98% for viral titers of 1 to 10 TCID50/0.1 ml, respectively; titers of 0.1 TCID50/0.1 ml resulted in a sensitivity of only 16%. The overall specificity of the Amplicor test was 98%. The Amplicor assay compared favorably to the five in-house PCR tests (no significant difference in either sensitivity or specificity) and was much more sensitive than tissue culture (P < 0.001), even for high viral loads. It was easy to perform, rapid (about 6 h), well-standardized, and appeared to be suitable for the diagnosis of enterovirus meningitis on a routine basis in laboratories trained in molecular biology techniques.

Base Sequence↗
PubMed1995

[Prospective study of neonatal genital mycoplasma colonization and infection].

Genital mycoplasmas have been implicated in different neonatal diseases as pneumonia, sepsis and meningitis. This prospective study was conducted to specify their role in these diseases. POPULATION AND METHODS--A pharyngeal or tracheal swab specimen for mycoplasmas culture was obtained from 100 infants admitted consecutively to the Neonatal Care Unit (NCU) during the first 24 hours of life. Mycoplasma culture of blood and cerebrospinal fluid was also performed. Pharyngeal and/or tracheal specimens were collected again on days 5, 15 and 28 if the child was still in the NCU. Mycoplasma hominis (Mh) and Ureaplasma urealyticum (Uu) were identified by culture in a modified Hayflick's medium. RESULTS--Three-hundred and ten pharyngeal or tracheal swabs were obtained (100 on day 0, 89 on day 5, 72 on day 15 and 49 on day 28). Twenty-one infants had one or more positive swabs in the first five days of life (20 on day 0 and one on day 5); those forming the "Myco+" group and the others forming the "Myco-" group. Uu was isolated alone from 20 infants, associated with Mh from one. Both groups were similar for gestational age, birth weight, maternal fever during labor, prolonged rupture of the fetal membranes or chorioamnionitis and for the incidence of acute respiratory distress. There was a statistically significant difference for the route of delivery (chi 2 < 0.02). One blood culture (from 92 performed) was positive for Uu and another positive for Uu and Mh. Both children were cured without any specific mycoplasmacidal therapy. Three children had probable Uu infection and were also cured without specific therapy. CONCLUSIONS--A pharyngeal colonization with genital mycoplasmas is common in the first days of life (21%) but our data do not allow us to conclude that they are accountable for newborn infections.

Bacteremia↗