RESUMEN
PURPOSE: This pilot study aimed to develop a methodology characterising the urogenital microbiome as a predictive test in the IVF workup. METHODS: Using unique custom qPCRs, we tested for the presence of specific microbial species from vaginal samples and First Catch Urines from the male. The test panel included a range of potential urogenital pathogens, STIs, 'favourable bacteria' (Lactobacillus spp.) and 'unfavourable bacteria' (anaerobes) reported to influence implantation rates. We tested couples attending Fertility Associates, Christchurch, New Zealand for their first round of IVF. RESULTS: We found that some microbial species affected implantation. The qPCR result was interpreted qualitatively using the Z proportionality test. Samples from women at the time of Embryo Transfer who did not achieve implantation had significantly higher percent of samples that were positive for Prevotella bivia and Staphylococcus aureus compared to women who did achieve implantation. DISCUSSION: The results provide evidence that most other microbial species chosen for testing had little functional effect on implantation rates. The addition of further microbial targets (yet to be determined) could be combined in this predictive test for vaginal preparedness on the day of embryo transfer. This methodology has a substantial advantage of being affordable and easily performed in any routine molecular laboratory. This methodology is most suitable as a foundation on which to develop a timely test of microbiome profiling. Using the indicators detected to have a significant influence, these results can be extrapolated. CONCLUSION: Using a rapid antigen test, a woman can self-sample prior to embryo transfer and obtain an indication of microbial species present which could influence implantation outcome.
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Implantación del Embrión , Fertilización In Vitro , Microbiota , Vagina , Femenino , Humanos , Masculino , Embarazo , Fertilización In Vitro/métodos , Proyectos Piloto , Índice de Embarazo , Vagina/microbiologíaRESUMEN
The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1-59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory.
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Técnicas de Laboratorio Clínico/normas , Neumonía/diagnóstico , Neumonía/etiología , Manejo de Especímenes/normas , Algoritmos , Preescolar , Exactitud de los Datos , Femenino , Infecciones por VIH , Humanos , Lactante , Masculino , Neumonía Bacteriana/diagnóstico , Neumonía Viral/diagnóstico , Control de Calidad , Estándares de Referencia , Infecciones del Sistema Respiratorio/etiologíaRESUMEN
BACKGROUND: Real-time multiplex PCR assays are increasingly used for respiratory virus detection, and offer automated analysis in a closed tube system, but they have the disadvantage of low-throughput due to multiplexing limitations. In this study, the established fast-track respiratory 21 assay (FTD) (fast-track diagnostics, Junglinster Luxembourg) was compared to the new Seegene Allplex assay (Seegene) (Seegene Inc. Seoul, Korea) which offers greater multiplexing as multiple targets can be detected in each fluorescence channel. The Seegene Allplex assay is quicker to perform than previous Seegene respiratory multiplex assays. MATERIALS AND METHODS: The assays were evaluated using 199 mostly upper respiratory tract samples. RESULTS: A respiratory pathogen was found in 127/199 (63.8%) of samples by the FTD assay and 123/199 (61.8%) using the Seegene assay. Kappa agreement was between 0.87 and 1 for all targets except human bocavirus and adenovirus. CONCLUSION: Although the performance of the assays were similar, the Seegene assay had the advantage of simultaneous detection of two gene targets for each of the common Influenza A subtypes, improved throughput of 30 samples per run and automated result analysis. The FTD assay could only test 17 samples per run but validation for use on several different real-time thermal cyclers made it easier to integrate into an existing laboratory system. Both assays were cost effective compared to in-house multiplex PCR respiratory virus screening.
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Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Juego de Reactivos para Diagnóstico , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Virus/aislamiento & purificación , Humanos , Estándares de ReferenciaRESUMEN
BACKGROUND: Few data exist describing pertussis epidemiology among infants and children in low- and middle-income countries to guide preventive strategies. METHODS: Children 1-59 months of age hospitalized with World Health Organization-defined severe or very severe pneumonia in 7 African and Asian countries and similarly aged community controls were enrolled in the Pneumonia Etiology Research for Child Health study. They underwent a standardized clinical evaluation and provided nasopharyngeal and oropharyngeal swabs and induced sputum (cases only) for Bordetella pertussis polymerase chain reaction. Risk factors and pertussis-associated clinical findings were identified. RESULTS: Bordetella pertussis was detected in 53 of 4200 (1.3%) cases and 11 of 5196 (0.2%) controls. In the age stratum 1-5 months, 40 (2.3% of 1721) cases were positive, all from African sites, as were 8 (0.5% of 1617) controls. Pertussis-positive African cases 1-5 months old, compared to controls, were more often human immunodeficiency virus (HIV) uninfected-exposed (adjusted odds ratio [aOR], 2.2), unvaccinated (aOR, 3.7), underweight (aOR, 6.3), and too young to be immunized (aOR, 16.1) (all P ≤ .05). Compared with pertussis-negative African cases in this age group, pertussis-positive cases were younger, more likely to vomit (aOR, 2.6), to cough ≥14 days (aOR, 6.3), to have leukocyte counts >20 000 cells/µL (aOR, 4.6), and to have lymphocyte counts >10 000 cells/µL (aOR, 7.2) (all P ≤ .05). The case fatality ratio of pertussis-infected pneumonia cases 1-5 months of age was 12.5% (95% confidence interval, 4.2%-26.8%; 5/40); pertussis was identified in 3.7% of 137 in-hospital deaths among African cases in this age group. CONCLUSIONS: In the postneonatal period, pertussis causes a small fraction of hospitalized pneumonia cases and deaths; however, case fatality is substantial. The propensity to infect unvaccinated infants and those at risk for insufficient immunity (too young to be vaccinated, premature, HIV-infected/exposed) suggests that the role for maternal vaccination should be considered along with efforts to reduce exposure to risk factors and to optimize childhood pertussis vaccination coverage.
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Neumonía/epidemiología , Neumonía/etiología , Tos Ferina/complicaciones , Tos Ferina/epidemiología , Bordetella pertussis/genética , Estudios de Casos y Controles , Coinfección , Países en Desarrollo , Femenino , Infecciones por VIH , Hospitalización , Humanos , Lactante , Recién Nacido , Masculino , Mortalidad , Oportunidad Relativa , Neumonía/diagnóstico , Vigilancia de la Población , Factores de Riesgo , Evaluación de Síntomas , Vacunación , Tos Ferina/prevención & controlRESUMEN
Corynebacterium species are increasingly recognized as important pathogens in granulomatous mastitis. Currently, there are no published treatment protocols for Corynebacterium breast infections. This study describes antimicrobial treatment options in the context of other management strategies used for granulomatous mastitis. Corynebacterium spp. isolated from breast tissue and aspirate samples stored from 2002 to 2013 were identified and determined to the species level using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), 16S RNA sequencing, and rpoB gene targets. The MICs for 12 antimicrobials were performed using Etest for each isolate. Correlations of these with antimicrobial characteristics, choice of antimicrobial, and disease outcome were evaluated. Corynebacterium spp. from breast tissue and aspirate samples were confirmed in 17 isolates from 16 patients. Based on EUCAST breakpoints, Corynebacterium kroppenstedtii isolates (n = 11) were susceptible to seven antibiotic classes but resistant to ß-lactam antibiotics. Corynebacterium tuberculostearicum isolates (n = 4) were multidrug resistant. Two nonlipophilic species were isolated, Corynebacterium glucuronolyticum and Corynebacterium freneyi, both of which have various susceptibilities to antimicrobial agents. Short-course antimicrobial therapy was common (median, 6 courses per subject; range, 1 to 9 courses). Patients with C. kroppenstedtii presented with a hot painful breast mass and underwent multiple surgical procedures (median, 4 procedures; range, 2 to 6 procedures). The management of Corynebacterium breast infections requires a multidisciplinary approach and includes culture and appropriate sensitivity testing to guide antimicrobial therapy. Established infections have a poor outcome, possibly because adequate concentrations of some drugs will be difficult to achieve in lipophilic granulomata. Lipophilic antimicrobial therapy may offer a therapeutic advantage. The role of immunotherapy has not been defined.
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Antibacterianos/uso terapéutico , Infecciones por Corynebacterium/tratamiento farmacológico , Infecciones por Corynebacterium/cirugía , Corynebacterium/efectos de los fármacos , Desbridamiento , Mastitis Granulomatosa/tratamiento farmacológico , Mastitis Granulomatosa/cirugía , Adulto , Anciano , Antibacterianos/farmacología , Análisis por Conglomerados , Corynebacterium/química , Corynebacterium/clasificación , Corynebacterium/genética , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ARN Polimerasas Dirigidas por ADN , Pruebas Antimicrobianas de Difusión por Disco , Femenino , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Adulto JovenRESUMEN
BACKGROUND: Legionnaires' disease cannot be clinically or radiographically distinguished from other causes of pneumonia, and specific tests are required to make the diagnosis. Currently, testing occurs erratically and, instead, clinicians rely on empiric treatment strategies and ignore public health implications of the diagnosis. We aimed to measure the increase in case detection of Legionnaires' disease following the introduction of routine polymerase chain reaction (PCR) testing of respiratory specimens. PCR is the most sensitive diagnostic tool for Legionnaires' disease. METHODS: In a quasi-experimental study in Christchurch, New Zealand, we compared the number of cases of Legionnaires' disease requiring hospitalization diagnosed during a 2-year period before the introduction of a routine PCR testing strategy (November 2008-October 2010) with a similar period after the introduction (November 2010-October 2012). With this testing strategy, all respiratory specimens from hospitalized patients with pneumonia sent to the region's sole tertiary-level laboratory were tested for Legionella by PCR, whether requested or not. RESULTS: During November 2008 to October 2010, there were 22 cases of Legionnaires' disease compared with 92 during November 2010 to October 2012. Of 1834 samples tested since November 2010, 1 in 20 was positive, increasing to 1 in 9 during peak Legionella season (November to January). Increasing bacterial load was associated with increasing disease severity. CONCLUSIONS: In our region, the burden of Legionnaires' disease is much greater than was previously recognized. Routine PCR testing provides results within a clinically relevant time frame and enables improved characterization of the regional epidemiology of Legionnaires' disease.
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Legionella/aislamiento & purificación , Enfermedad de los Legionarios/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Legionella/genética , Masculino , Persona de Mediana Edad , Nueva Zelanda , Sensibilidad y EspecificidadRESUMEN
The differentiation of species within the Streptococcus mitis group has posed a problem in the routine diagnostic microbiology laboratory for some time. It also constitutes a major weakness of recently introduced matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) fingerprinting systems. As the phylogenetic resolution of the spectral similarity measures employed by these systems is insufficient to reliably distinguish between the most closely related members of the group, the major pathogen Streptococcus pneumoniae is frequently misidentified. In this study, a comparative analysis of MALDI-TOF spectra of several species from the S. mitis group has been performed in order to identify single peaks that could be used to improve mass spectrometry-based identification of the respective species. A characteristic peak profile could be identified that unambiguously distinguished the 14 S. pneumoniae isolates studied from 33 nonpneumococcal isolates of the S. mitis group. In addition, specific peak combinations could be assigned to other members of the group. The findings of this study suggest that it is possible to distinguish different species of the S. mitis group by close analysis of their mass peak profiles.
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Técnicas Bacteriológicas/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/microbiología , Streptococcus/química , Streptococcus/clasificación , ADN Bacteriano/química , ADN Bacteriano/genética , Humanos , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Streptococcus/aislamiento & purificaciónRESUMEN
Strains identified as Campylobacter concisus may belong to one of at least two biochemically indistinguishable, but genomically distinct, groups referred to as "genomospecies" that may differ in their pathogenic and zoonotic potential. Reliable, affordable and available identification methods are required to improve understanding of their significance in human illness. We examined the potential for MALDI-TOF MS, increasingly used in routine laboratories, for this task. Nineteen well-characterised strains were examined using a widely used MALDI-TOF MS commercial system, however only one strain confidently identified using their database. Data mining of the spectra obtained revealed a number of markers that could be used to help discriminate these genomospecies. We conclude that careful application of MALDI-TOF analysis could be useful to determine the role and significance of diverse C. concisus genomospecies in human disease.
RESUMEN
Corynebacterium accolens is a rare human pathogen. We encountered a case of C. accolens isolated from a thigh collection in a man with osteomyelitis of the adjacent pubic symphysis.
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Infecciones por Corynebacterium/diagnóstico , Corynebacterium/aislamiento & purificación , Osteomielitis/diagnóstico , Sínfisis Pubiana/microbiología , Sínfisis Pubiana/patología , Anciano , Antibacterianos/farmacología , Corynebacterium/clasificación , Corynebacterium/genética , Infecciones por Corynebacterium/microbiología , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Osteomielitis/microbiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNAsunto(s)
Legionella/genética , Enfermedad de los Legionarios/diagnóstico , Enfermedad de los Legionarios/microbiología , Faringe/patología , Reacción en Cadena de la Polimerasa/métodos , Esputo/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Esputo/microbiología , Adulto JovenRESUMEN
Campylobacter fetus has been isolated as an infrequent cause of abscesses. We report a case of Campylobacter fetus epidural abscess and bacteremia in a debilitated elderly man who had a fatal outcome.
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Bacteriemia/microbiología , Infecciones por Campylobacter/diagnóstico , Campylobacter fetus/aislamiento & purificación , Absceso Epidural/microbiología , Anciano de 80 o más Años , Resultado Fatal , Humanos , MasculinoRESUMEN
BACKGROUND: Legionnaires' disease is under-diagnosed because of inconsistent use of diagnostic tests and uncertainty about whom to test. We assessed the increase in case detection following large-scale introduction of routine PCR testing of respiratory specimens in New Zealand. METHODS: LegiNZ was a national surveillance study done over 1-year in which active case-finding was used to maximise the identification of cases of Legionnaires' disease in hospitals. Respiratory specimens from patients of any age with pneumonia, who could provide an eligible lower respiratory specimen, admitted to one of 20 participating hospitals, covering a catchment area of 96% of New Zealand's population, were routinely tested for legionella by PCR. Additional cases of Legionnaires' disease in hospital were identified through mandatory notification. FINDINGS: Between May 21, 2015, and May 20, 2016, 5622 eligible specimens from 4862 patients were tested by PCR. From these, 197 cases of Legionnaires' disease were detected. An additional 41 cases were identified from notification data, giving 238 cases requiring hospitalisation. The overall incidence of Legionnaires' disease cases in hospital in the study area was 5·4 per 100â000 people per year, and Legionella longbeachae was the predominant cause, found in 150 (63%) of 238 cases. INTERPRETATION: The rate of notified disease during the study period was three-times the average over the preceding 3 years. Active case-finding through systematic PCR testing better clarified the regional epidemiology of Legionnaires' disease and uncovered an otherwise hidden burden of disease. These data inform local Legionnaires' disease testing strategies, allow targeted antibiotic therapy, and help identify outbreaks and effective prevention strategies. The same approach might have similar benefits if applied elsewhere in the world. FUNDING: Health Research Council of New Zealand.
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Brotes de Enfermedades/estadística & datos numéricos , Enfermedad de los Legionarios/diagnóstico , Enfermedad de los Legionarios/epidemiología , Vigilancia de la Población , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Notificación de Enfermedades , Femenino , Humanos , Incidencia , Legionella pneumophila/aislamiento & purificación , Masculino , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Reacción en Cadena de la Polimerasa , Adulto JovenRESUMEN
Murine typhus was diagnosed by PCR in 50 (7%) of 756 adults with febrile illness seeking treatment at Patan Hospital in Kathmandu, Nepal. Of patients with murine typhus, 64% were women, 86% were residents of Kathmandu, and 90% were unwell during the winter. No characteristics clearly distinguished typhus patients from those with blood culture-positive enteric fever.
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Tifus Endémico Transmitido por Pulgas/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Diagnóstico Diferencial , Femenino , Fiebre/microbiología , Humanos , Masculino , Persona de Mediana Edad , Nepal/epidemiología , Reacción en Cadena de la Polimerasa , Rickettsia typhi/genética , Rickettsia typhi/aislamiento & purificación , Fiebre Tifoidea/diagnóstico , Fiebre Tifoidea/epidemiología , Tifus Endémico Transmitido por Pulgas/diagnóstico , Tifus Endémico Transmitido por Pulgas/microbiologíaAsunto(s)
Viabilidad Microbiana , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Mycobacterium tuberculosis/fisiología , Ácidos Nucleicos/aislamiento & purificación , Salud Laboral , Juego de Reactivos para Diagnóstico , Técnicas Bacteriológicas , Humanos , Exposición ProfesionalRESUMEN
AIMS: The primary aim of the study was to determine if the gonococcal porA pseudogene is a stable sequence target for the detection of Neisseria gonorrhoeae by PCR. METHODS: A total of 240 gonococcal strains from various geographic locations were tested by porA pseudogene PCR. In addition, porA pseudogene PCR positivity rates were compared with established gonococcal assays in three Australian states. RESULTS: All N. gonorrhoeae isolates provided positive results in the porA pseudogene PCR. Positivity rates compared favourably with established gonococcal assays, with increased N. gonorrhoeae detection in the Northern Territory and Western Australia. CONCLUSIONS: The results of this multicentre study provide further evidence that the porA pseudogene is highly conserved across a diverse range N. gonorrhoeae strains and is a suitable PCR target for routine detection of N. gonorrhoeae.
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Técnicas de Diagnóstico Urológico , Gonorrea/diagnóstico , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/aislamiento & purificación , Porinas/genética , Reacciones Falso Positivas , Gonorrea/microbiología , Humanos , Neisseria gonorrhoeae/clasificación , Reacción en Cadena de la Polimerasa , Reproducibilidad de los Resultados , Especificidad de la EspecieRESUMEN
AIM: To compare PCR with galactomannan antigen detection for the diagnosis of invasive aspergillosis (IA). METHODS: We prospectively collected serial blood samples from haematological patients at risk of IA, and analysed their samples retrospectively for galactomannan (GM) antigen using the Platelia test and for aspergillus DNA using an in-house PCR-ELISA assay. Matched GM and PCR analyses were performed on 263 samples from 25 patients. Patients were classified for potential IA according to international consensus criteria, with five patients classified as positive (four proven, one probable) and 20 classified as negative (seven possible, 13 no evidence IA). RESULTS: All five patients with IA were positive by PCR with positive results in 24 of 82 samples, whereas three of five patients were positive by GM with four of 82 samples being positive. Three of 20 patients without IA were positive by PCR in 18 of 181 samples, whereas corresponding results for GM detection were one of 20 and one of 181, respectively. Adjustment of ELISA cut-off values and/or the requirement for two consecutive samples to be positive generated different results; however, lowering the positivity index (PI) for GM detection to 0.5 did not improve the sensitivity of the assay. Optimal results for PCR detection and GM were: 100% and 60% sensitivity, 85% and 95% specificity, 0.625 and 0.75 positive predictive value, and 1.0 and 0.8 negative predictive value, with a false-positive sample rate of 8 and 0.4%, positive likelihood ratio of 6.66 and 11.99 and negative likelihood ratio of 0 and 0.42, respectively. CONCLUSIONS: This PCR method is very sensitive for the diagnosis of IA but is associated with a moderate rate of false positives; the GM assay exhibited poor sensitivity but high specificity. Further evaluation of PCR assays for the diagnosis of IA and other invasive fungal infections is warranted.
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Antígenos Fúngicos/sangre , Aspergilosis/diagnóstico , Aspergillus/inmunología , Ensayo de Inmunoadsorción Enzimática , Mananos/sangre , Reacción en Cadena de la Polimerasa , Adolescente , Adulto , Anciano , Animales , Aspergillus/genética , Preescolar , Reacciones Falso Positivas , Femenino , Galactosa/análogos & derivados , Humanos , Masculino , Mananos/inmunología , Mananos/metabolismo , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Findings of polymerase chain reaction (PCR) studies of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) and breast cancer vary, making it difficult to determine whether either, both, or neither virus is causally associated with breast cancer. We investigated CMV and EBV in paired samples of breast cancer and normal breast tissue from 70 women using quantitative PCR. A serum sample from each woman was tested for CMV and EBV IgG. To place our results in context, we reviewed the existing literature and performed a meta-analysis of our results together with previous PCR studies of EBV, CMV, and breast cancer. Of the serology samples, 67 of 70 (96%) were EBV IgG positive and 49 of 70 (70%) were CMV IgG positive. QPCR detected EBV in 24 (34%) of the tumour and 9 (13%) of the paired normal specimens and CMV in 0 (0%) of the tumour and 2 (3%) of the paired normal specimens. Our findings, together with earlier results summarised in the meta-analysis, suggest several possibilities: variable findings may be due to limitations of molecular analyses; 'hit and run' oncogenesis may lead to inconsistent results; one or both viruses has a role at a later stage in breast cancer development; infection with multiple viruses increases breast cancer risk; or neither virus has a role. Future studies should focus on ways to investigate these possibilities, and should include comparisons of breast cancer tissue samples with appropriate normal tissue samples.
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Anticuerpos Antivirales/sangre , Neoplasias de la Mama/virología , Carcinoma/virología , Citomegalovirus/inmunología , Herpesvirus Humano 4/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Citomegalovirus/aislamiento & purificación , Femenino , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Inmunoglobulina G/sangre , Persona de Mediana EdadRESUMEN
BACKGROUND: Viral lower respiratory tract infections are a leading cause of hospitalization for young children. METHODS: We used polymerase chain reaction (PCR) and conventional methods of cell culture and antigen detection to establish the viral etiology of acute respiratory tract infections in 75 hospitalized children. RESULTS: One or more viral pathogens were detected in 65 (87%) children, with respiratory syncytial virus being the most commonly identified virus (36 children). Other viruses identified included influenza virus types A and B, parainfluenzavirus type 3, adenovirus, enterovirus, rhinovirus, coronavirus and human metapneumovirus. PCR increased the diagnostic yield significantly compared with antigen detection and culture, with 39 (21%) diagnoses identified by this method. Multiple infections were identified in 20 (27%) children. CONCLUSIONS: PCR-based methodologies offer increased sensitivity for the detection of most respiratory viruses in young children. The inclusion of PCR into diagnostic testing strategies is needed to broaden our understanding of the natural ecology of respiratory viruses and the significance of multiple infections.
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Orthomyxoviridae/clasificación , Reacción en Cadena de la Polimerasa , Infecciones del Sistema Respiratorio/virología , Enfermedad Aguda , Distribución por Edad , Antivirales/administración & dosificación , Preescolar , Estudios de Cohortes , Femenino , Hospitalización/estadística & datos numéricos , Hospitales Pediátricos , Humanos , Incidencia , Lactante , Masculino , Orthomyxoviridae/efectos de los fármacos , Probabilidad , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/epidemiología , Muestreo , Sensibilidad y Especificidad , Distribución por SexoRESUMEN
Multiplex PCR has become the test of choice for the detection of multiple respiratory viruses in clinical specimens. However, there are few direct comparisons of different PCR assays. This study compares 4 different multiplex PCR assays for the recovery of common respiratory viruses. We tested 213 respiratory specimens using four different multiplex PCR assays: the xTAG respiratory viral panel fast (Abbott Molecular Laboratories), Fast-track Respiratory Pathogen assay (Fast-track Diagnostics), Easyplex respiratory pathogen 12 kit (Ausdiagnostics), and an in-house multiplex real-time PCR assay. The performance of the four assays was very similar, with 93-100% agreement for all comparisons. Other issues, such as through-put, technical requirements and cost, are likely to be as important for making a decision about which of these assays to use given their comparative performance.