RESUMEN
Influenza virus infection is a common cause of self-limiting respiratory tract infection (RTI), however immunocompromised patients are at an increased risk for a severe course of disease or fatal outcome. We therefore aimed to gain a better understanding of the molecular epidemiology of influenza viruses from patients with haematological disorders and their impact on the clinical course of disease. Molecular analysis using polymerase chain reaction (PCR) of nasopharyngeal swabs was performed for influenza virus in haematological patients at the Heidelberg University Hospital. Clinical data was evaluated to identify associated risk factors. For phylogenetic analysis, the hemagglutinin (HA) gene was sequenced. Out of 159 influenza positive patients, 117 patients developed upper RTI (influenza A: n = 73; influenza B: n = 44). Lower RTI was observed in n = 42 patients (26%), n = 22/42 patients developed severe disease and n = 16/159 (10.1%) patients died. Risk factors for lower RTI were nosocomial infection (p = 0.02), viral shedding for ≥14 days (p = 0.018), IgG levels <6 g/dL (p = 0.046), bacterial/fungal co-infections (p < 0.001). Risk factors for fatal outcome were age ≥65 years (p = 0.032), bacterial/fungal (p≤0.001) co-infections and high viral load (p = 0.026). Sequencing of the HA gene (n = 115) revealed subtype A(H3N2) (n = 46), A(H1N1)pdm09 (n = 24), B/Victoria (n = 34), B/Yamagata (n = 11). There was no correlation between influenza (sub)type and lower RTI. Influenza infection in haematological patients is associated with significant morbidity and mortality, the risk for aggravating co-infections, prolonged viral shedding and nosocomial transmission emphasizing the need for infection control.
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Coinfección , Enfermedades Transmisibles , Enfermedades Hematológicas , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Infecciones del Sistema Respiratorio , Humanos , Anciano , Gripe Humana/complicaciones , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Epidemiología Molecular , Filogenia , Gravedad del Paciente , Enfermedades Hematológicas/complicacionesRESUMEN
Respiratory syncytial virus (RSV) is the most common cause of acute respiratory tract infection in infants and young children often leading to severe disease requiring hospitalization. However, validated tools for systematic assessment of disease severity are lacking. This study aimed at creating and validating a standardized, simple-to-use disease severity score for RSV infection in children-the RSV-CLASS (Clinical Assessment Severity Score). Therefore, data from over 700 RSV-infected children over six winter seasons (2014-2020) was analyzed using univariate and multiple regression analyses for the prediction of lower respiratory tract infection (LRTI) as a proxy for a severe course of the disease. Testing a broad range of respiratory symptoms, they eventually yielded seven items. Performing stepwise selection, these were reduced to the final four items: cough, tachypnea, rales, and wheezing, each receiving one point in the proposed score named RSV-CLASS. The score was calculated for children in two cohorts A and B, one for development and one for validation, with an area under the curve of 0.90 and 0.87, respectively. With a score value of 3 or 4, 97.8% and 100% of the children, respectively, were admitted with LRTI and classified correctly. The RSV-CLASS is a disease severity score based on a neutral, analytical approach using prospective data from a large study cohort. It will contribute to systematically assessing the disease severity of RSV infection and can be used for evidence-based clinical decision-making as well as for research settings.
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Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Lactante , Niño , Humanos , Preescolar , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Niño Hospitalizado , Estudios Prospectivos , Hospitalización , Gravedad del Paciente , Ruidos Respiratorios/etiologíaRESUMEN
Data on cross-neutralization of the SARS-CoV-2 omicron variant more than 1 year after SARS-CoV-2 infection are urgently needed, especially in children, to predict the likelihood of reinfection and to guide vaccination strategies. In a prospective observational cohort study, we evaluated live-virus neutralization of the SARS-CoV-2 omicron (BA.1) variant in children compared with adults 14 months after mild or asymptomatic wild-type SARS-CoV-2 infection. We also evaluated immunity to reinfection conferred by previous infection plus COVID-19 mRNA vaccination. We studied 36 adults and 34 children 14 months after acute SARS-CoV-2 infection. While 94% of unvaccinated adults (16/17) and children (32/34) neutralized the delta (B.1.617.2) variant, only 1/17 (5.9%) unvaccinated adults, 0/16 (0%) adolescents and 5/18 (27.8%) children <12 years of age had neutralizing activity against omicron (BA.1). In convalescent adults, one or two doses of mRNA vaccine increased delta and omicron neutralization 32-fold, similar to a third mRNA vaccination in uninfected adults. Neutralization of omicron was 8-fold lower than that of delta in both groups. In conclusion, our data indicate that humoral immunity induced by previous SARS-CoV-2 wild-type infection more than 1 year ago is insufficient to neutralize the current immune escape omicron variant.
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COVID-19 , Adolescente , Humanos , Adulto , Niño , COVID-19/prevención & control , SARS-CoV-2/genética , Estudios Prospectivos , Reinfección , ARN Mensajero , Anticuerpos Neutralizantes , Anticuerpos AntiviralesRESUMEN
OBJECTIVES: This study investigated the molecular epidemiology of respiratory syncytial virus (RSV) among febrile children with acute respiratory tract infection in Ghana, Gabon, Tanzania and Burkina Faso between 2014 and 2017 as well as the evolution and diversification of RSV strains from other sub-Saharan countries. METHODS: Pharyngeal swabs were collected at four study sites (Agogo, Ghana: n = 490; Lambaréné, Gabon: n = 182; Mbeya, Tanzania: n = 293; Nouna, Burkina Faso: n = 115) and analysed for RSV and other respiratory viruses using rtPCR. For RSV-positive samples, sequence analysis of the second hypervariable region of the G gene was performed. A dataset of RSV strains from sub-Saharan Africa (2011-2017) currently available in GenBank was compiled. Phylogenetic analysis was conducted to identify the diversity of circulating RSV genotypes. RESULTS: In total, 46 samples were tested RSV positive (Ghana n = 31 (6.3%), Gabon n = 4 (2.2%), Tanzania n = 9 (3.1%) and Burkina Faso n = 2 (1.7%)). The most common RSV co-infection was with rhinovirus. All RSV A strains clustered with genotype ON1 strains with a 72-nucleotide duplication and all RSV B strains belonged to genotype BAIX. Phylogenetic analysis of amino acid sequences from sub-Saharan Africa revealed the diversification into 11 different ON1 and 22 different BAIX lineages and differentiation of ON1 and BAIX strains into potential new sub-genotypes, provisionally named ON1-NGR, BAIX-KEN1, BAIX-KEN2 and BAIX-KEN3. CONCLUSION: The study contributes to an improved understanding of the molecular epidemiology of RSV infection in sub-Saharan Africa. It provides the first phylogenetic data for RSV from Tanzania, Gabon and Burkina Faso and combines it with RSV strains from all other sub-Saharan countries currently available in GenBank.
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Epidemiología Molecular/métodos , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Infecciones por Virus Sincitial Respiratorio/genética , Virus Sincitial Respiratorio Humano/genética , África del Sur del Sahara , Burkina Faso , Preescolar , Femenino , Gabón , Genotipo , Ghana , Glicosilación , Humanos , Lactante , Masculino , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADN/métodos , TanzaníaRESUMEN
Serological assays detecting antibodies in serum or plasma samples are useful and versatile instruments to investigate an individual's infection and vaccination history, e.g. for clinical diagnosis, personal risk evaluation, and seroepidemiological studies. Multiplex Serology is a suspension bead array-based high-throughput methodology for simultaneous measurement of antibodies against multiple pathogens in a single reaction vessel, thus economizing sample volume, measurement time, and costs. We developed and validated bead-based pathogen-specific Monoplex Serology assays, i.e. assays including only antigens for the respective pathogen, to detect antibodies against Corynebacterium diphtheriae and Clostridium tetani toxins, rubella virus and parvovirus B19. The developed assays expand the portfolio of existing pathogen-specific bead-based serology assays and can be efficiently incorporated into larger Multiplex Serology panels. The newly developed Monoplex Serology assays consist of only one antigen per infectious agent, expressed as Glutathione S-transferase-fusion proteins in E. coli. Specificity, sensitivity and Cohen's kappa statistics in comparison with routine clinical diagnostic assays were calculated for serum dilutions 1:100 and 1:1000. All pathogen-specific assays were successfully validated at both serum dilutions with the exception of rubella Monoplex Serology which showed impaired sensitivity (57.6%) at dilution 1:1000. Specificities of successfully validated Monoplex Serology assays ranged from 85.6% to 100.0% (median: 91.7%), and sensitivities from 81.3% to 95.8% (median: 90.9%); agreement with the reference assays ranged from substantial to almost perfect (kappa: 0.66-0.86, median: 0.78). Statistical performance and slim assay design enable efficient incorporation of the developed assays into Multiplex Serology.
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Anticuerpos Antibacterianos/aislamiento & purificación , Anticuerpos Antivirales/aislamiento & purificación , Ensayos Analíticos de Alto Rendimiento/métodos , Pruebas Serológicas/métodos , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Antígenos Bacterianos/genética , Antígenos Bacterianos/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , Clostridium tetani/inmunología , Corynebacterium diphtheriae/inmunología , Difteria/sangre , Difteria/diagnóstico , Difteria/inmunología , Difteria/microbiología , Ensayo de Inmunoadsorción Enzimática/instrumentación , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayos Analíticos de Alto Rendimiento/instrumentación , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina G/aislamiento & purificación , Fenómenos Magnéticos , Microesferas , Modelos Animales , Infecciones por Parvoviridae/sangre , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/inmunología , Infecciones por Parvoviridae/virología , Parvovirus B19 Humano/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Rubéola (Sarampión Alemán)/sangre , Rubéola (Sarampión Alemán)/diagnóstico , Rubéola (Sarampión Alemán)/inmunología , Rubéola (Sarampión Alemán)/virología , Virus de la Rubéola/inmunología , Sensibilidad y Especificidad , Pruebas Serológicas/instrumentación , Tétanos/sangre , Tétanos/diagnóstico , Tétanos/inmunología , Tétanos/microbiología , Toxina Tetánica/genética , Toxina Tetánica/inmunologíaRESUMEN
BACKGROUND: JC polyomavirus (JCPyV)-associated nephropathy (JCPyVAN) is a severe, but rare complication in adult renal transplant (RTx) recipients. Related data in pediatric patients are scarce. METHODS: Based on the CERTAIN Registry, we therefore performed a multi-center, retrospective study on the JCPyV antibody status, prevalence of JCPyV replication, and its associated disease in 139 pediatric RTx recipients (mean age, 8.5 ± 5.3 years). JCPyV DNA in plasma and/or urine was measured by quantitative PCR at a median time of 3.2 (IQR, 0.3-8.1) years post-transplant. RESULTS: 53.2% of patients were JCPyV-seronegative prior to transplantation; younger age was associated with JCPyV seronegativity. 34/139 (24.5%) patients post-transplant showed active JCPyV replication in either urine (22.0%), plasma (13.4%), or both (7.6%). JCPyV viremia occurred significantly (p < 0.001) more often in patients with viruria (34.6%) than in those without (7.6%), but 7/118 (5.9%) had isolated viremia. High-level viruria (> 107 copies/mL) was found in 29.6% of viruric patients. A higher net state of immunosuppression constituted an independent risk factor for JCPyV replication both in urine and plasma (OR 1.2, p < 0.02). Male patients tended to have a higher risk of JCPyV viremia than females (OR 4.3, p = 0.057). There was one male patient (0.7%) with JCPyVAN 7 years post-transplant, which resolved after reduction of immunosuppressive therapy. No patient exhibited progressive multifocal leukoencephalopathy. CONCLUSIONS: This first multi-center study on JCPyV in pediatric renal transplant recipients shows that JCPyV replication is common (24.5%), with strong immunosuppression being a significant risk factor, but associated nephropathy is rare.
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Virus JC/aislamiento & purificación , Enfermedades Renales/epidemiología , Trasplante de Riñón/efectos adversos , Infecciones por Polyomavirus/epidemiología , Viremia/epidemiología , Adolescente , Niño , Preescolar , Femenino , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Humanos , Terapia de Inmunosupresión/efectos adversos , Enfermedades Renales/inmunología , Enfermedades Renales/virología , Masculino , Infecciones por Polyomavirus/inmunología , Infecciones por Polyomavirus/virología , Prevalencia , Sistema de Registros/estadística & datos numéricos , Estudios Retrospectivos , Receptores de Trasplantes/estadística & datos numéricos , Viremia/inmunología , Viremia/virologíaRESUMEN
Alere i RSV is a novel rapid test which applies a nicking enzyme amplification reaction to detect respiratory syncytial virus in point-of-care settings. In this study, we evaluated the Alere i RSV assay by using frozen nasopharyngeal swab samples that were collected in viral transport medium from children hospitalized with acute respiratory tract infection during the 2015-2016 winter season. Alere i RSV assay results were compared to those for Altona RealStar RSV real-time reverse transcription-PCR (RT-PCR). We found that the overall sensitivity and specificity of the Alere i RSV test was 100% (95% confidence intervals [CI], 93% to 100%) and 97% (95% CI, 89% to 100%), respectively. Positive samples were identified within 5 to 7 min from sample collection. Overall, the Alere i RSV test performed well compared to the RT-PCR assay and has the potential to facilitate the detection of RSV in point-of-care settings.
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Hospitalización , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Sistemas de Atención de Punto , Virus Sincitiales Respiratorios/aislamiento & purificación , Infecciones del Sistema Respiratorio/diagnóstico , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
BACKGROUND: Respiratory syncytial virus (RSV) is the most important cause of severe acute respiratory tract infection in young children. Alere i RSV is a novel molecular rapid test which identifies respiratory syncytial virus in less than 13 min. METHODS: We evaluated the clinical performance of the Alere i RSV assay in a pediatric point-of-care setting during winter season 2016 / 2017. Test results from 518 nasopharyngeal swab samples were compared to a real-time reverse transcription PCR reference standard. RESULTS: The overall sensitivity and specificity of the Alere i RSV test assay was 93% (CI95 89% - 96%) and 96% (CI95 93% - 98%), respectively. Alere i RSV performed well in children of all age groups. An optimal sensitivity of 98% (CI95 94% - 100%) and specificity of 96% (CI95 90% - 99%) was obtained in children < 6 months. In children ≥ 2 years, sensitivity and specificity remained at 87% (CI95 73% - 96%) and 98% (CI95 92% - 100%), respectively. False negative Alere i RSV test results mostly occurred in samples with low viral load (mean CT value 31.1; CI95 29.6 - 32.6). The Alere i RSV assay is easy to use and can be operated after minimal initial training. Test results are available within 13 min, with most RSV positive samples being identified after approximately 5 min. CONCLUSION: The Alere i RSV assay has the potential to facilitate the detection of RSV in pediatric point-of-care settings.
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Infecciones por Virus Sincitial Respiratorio/diagnóstico , Virus Sincitial Respiratorio Humano/genética , Preescolar , Reacciones Falso Positivas , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Nasofaringe/virología , Sistemas de Atención de Punto , ARN Viral/análisis , Juego de Reactivos para Diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Sensibilidad y EspecificidadRESUMEN
Background: Viral acute respiratory tract infections (ARTIs) are a leading cause of hospitalization in infants and young children. Methods: During the winter seasons of 2014-2018, hospitalized children (<18 years) with symptoms of ARTI were prospectively included at the University Hospital Heidelberg, Germany. Nasopharyngeal swabs were obtained for multiplex molecular analysis of 10 groups of respiratory viruses, and clinical data were obtained using a standardized questionnaire. Results: Of 1353 children included in this study, 1142 (84.4%) were positive for ≥1 viral pathogen. Virus monoinfection was detected in 797 (69.8%) children, whereas 345 (30.2%) children had coinfections with 2-4 viral pathogens. Respiratory syncytial virus (RSV), rhinovirus, and influenza virus were the main pathogens detected. RSV-positive children had significantly more often lower ARTIs, including symptoms of severe cough, wheezing, chest indrawing, tachypnea, and pulmonary rales. Hospitalized children aged <6 months represented the largest age group with detection of ≥1 viral pathogen (455/528 [86.2%] children). Coinfection was more frequent in younger children and, particularly for RSV with rhinovirus, significantly associated with more severe respiratory symptoms (P = .01). Conclusions: A better understanding of the etiology of viral ARTIs among hospitalized children plays a key role for future strategies in prevention, control, and treatment of respiratory viral infections.
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To assess morbidity and mortality of parainfluenza virus (PIV) infections in immunocompromised patients, we analysed PIV infections in a hematology and stem cell transplantation (SCT) unit over the course of three years. Isolated PIV strains were characterized by sequence analysis and nosocomial transmission was assessed including phylogenetic analysis of viral strains. 109 cases of PIV infection were identified, 75 in the setting of SCT. PIV type 3 (n = 68) was the most frequent subtype. PIV lower respiratory tract infection (LRTI) was observed in 47 patients (43%) with a mortality of 19%. Severe leukopenia, prior steroid therapy and presence of co-infections were significant risk factors for development of PIV-LRTI in multivariate analysis. Prolonged viral shedding was frequently observed with a median duration of 14 days and up to 79 days, especially in patients after allogeneic SCT and with LRTI. Nosocomial transmission occurred in 47 patients. Phylogenetic analysis of isolated PIV strains and combination with clinical data enabled the identification of seven separate clusters of nosocomial transmission. In conclusion, we observed significant morbidity and mortality of PIV infection in hematology and transplant patients. The clinical impact of co-infections, the possibility of long-term viral shedding and frequent nosocomial transmission should be taken into account when designing infection control strategies.
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Coinfección , Infección Hospitalaria , Neoplasias Hematológicas , Trasplante de Células Madre Hematopoyéticas , Infecciones por Paramyxoviridae , Infecciones del Sistema Respiratorio , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Virus de la Parainfluenza 3 Humana/genética , Filogenia , Infecciones del Sistema Respiratorio/epidemiología , Trasplante de Células Madre/efectos adversos , Esparcimiento de VirusRESUMEN
BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in young children. Early detection of RSV infection can avoid unnecessary diagnostic and therapeutic intervention and is required to prevent the nosocomial spread of RSV infection in pediatric hospitals. We developed a web tool to calculate the probability of RSV infection in children hospitalized with acute respiratory tract infection (ARTI) (RSVpredict). METHODS: During winter seasons 2014/2015 to 2017/2018, 1545 children hospitalized with clinical symptoms of ARTI at the University Hospital Heidelberg/Germany were prospectively included. Medical information was reported on a standardized data sheet, and nasopharyngeal swabs were obtained for multiplex real-time polymerase chain reaction analyses. We applied logistic regression to develop a prediction model and developed a web-based application to predict the individual probability of RSV infection. RESULTS: Duration of clinical symptoms ≥2 days on admission, calendar month of admission, admission for lower respiratory tract infection, the presence of cough and rale and younger age were associated with RSV infection (P < 0.05). Those data were included in the prediction model (RSVpredict, https://web.imbi.uni-heidelberg.de/rsv/). RSVpredict is a web-based application to calculate the risk of RSV infection in children hospitalized with ARTI. The prediction model is based on easily accessible clinical symptoms and predicts the individual probability of RSV infection risk immediately. CONCLUSIONS: Pediatricians might use the RSVpredict to take informed decisions on further diagnostic and therapeutic intervention, including targeted RSV testing in children with relevant RSV infection risk.
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Sistemas de Apoyo a Decisiones Clínicas , Hospitalización , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Adolescente , Niño , Preescolar , Pruebas Diagnósticas de Rutina , Femenino , Alemania , Hospitales Universitarios , Humanos , Lactante , Recién Nacido , Internet , Masculino , Nasofaringe/virología , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Programas InformáticosRESUMEN
We report a case of lower respiratory tract infection with human bocavirus 1 (HboV1) in an immunodeficient 6-month-old boy leading to respiratory failure with fatal outcome. Polymerase chain reaction of serum/tracheal secretions revealed exceptionally high HboV1-DNA levels and immunoassays showed seroconversion indicating an acute primary HboV1 infection. All assays for other pathogens were negative, strongly suggesting that HboV1 was the causative agent in this case.
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Bocavirus Humano/patogenicidad , Huésped Inmunocomprometido , Infecciones por Parvoviridae/diagnóstico , Infecciones del Sistema Respiratorio/diagnóstico , ADN Viral/genética , Resultado Fatal , Bocavirus Humano/genética , Humanos , Lactante , Masculino , Técnicas de Diagnóstico Molecular , Infecciones por Parvoviridae/virología , Infecciones del Sistema Respiratorio/virología , Índice de Severidad de la Enfermedad , Esparcimiento de VirusRESUMEN
Background: The physical examination (PE) of patients is a core competence in almost all medical disciplines. The teaching materials "Heidelberger Standard Examination", consisting of a handbook and accompanying videos, were developed with the objective of providing medical students with an innovative faculty-wide teaching and examination standard to sustainably advance students' PE competences during medical training. Methods: In a "mixed-method approach" comprising both quantitative and qualitative measures, our study examined Heidelberg University Hospital final year (FY) medical students' use and evaluation of the individual teaching material components. Therefore, 92 FY students completed quantitative evaluation measures and ten FY students took part in individual 30-minute semi-structured interviews. Results: Of the sample of n=77 students, who had completed the clinical part of their studies at Heidelberg University Hospital, 97.4% (n=75) had used the handbook and 35.0% (n=27) the accompanying videos. The teaching materials were evaluated via the common German six-point school grading system with an average mark of 1.35±0.5 for the handbook and a mark of 2.15±1.0 for the accompanying videos. Further, our results show that FY students especially valued the "Heidelberg Standard Examination" handbook as a guide and general reference work and felt the materials improved their self-perceived PE competence. Although FY students saw the accompanying video material as helpful, it was less frequently used, indicating further development potential. Overall, results reveal that FY students perceive the "Heidelberg Standard Examination" teaching program to contribute to the improvement of the quality of their PE training.
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Competencia Clínica , Examen Físico , Estudiantes de Medicina , Curriculum , Educación de Pregrado en Medicina , Alemania , HumanosRESUMEN
Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in young infants and a major cause of nosocomial infection in pediatric care. Currently available RSV point-of-care tests are of limited sensitivity and relatively expensive. We developed and evaluated a novel RSV rapid test for use at point-of-care, based on reverse-transcription loop-mediated isothermal amplification (RT-LAMP) for direct testing of nasopharyngeal swab specimens. RT-LAMP can detect RSV within 30min, without the need for RNA extraction. The sensitivity of our RT-LAMP assay was 70-80% in comparison to RT-PCR. The RT-LAMP test sensitivity is at least equivalent to currently available rapid antigen detection tests (RADT), and the cost of RT-LAMP test reagents is only approximately 10% of that of commercially available RADT tests. RT-LAMP appears to be an attractive alternative to RADT, particularly in settings with limited financial resources. Future improvements could include lyophilization of test reagents and automated read-out of RT-LAMP results.
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Nasofaringe/virología , Técnicas de Amplificación de Ácido Nucleico , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Transcripción Reversa , Preescolar , Cartilla de ADN , Femenino , Humanos , Lactante , Masculino , Técnicas de Amplificación de Ácido Nucleico/economía , Sistemas de Atención de Punto , ARN Viral/análisis , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/genética , Sensibilidad y Especificidad , Temperatura , Factores de TiempoRESUMEN
Human noroviruses are the dominant cause of outbreaks of acute gastroenteritis. These viruses are usually detected by molecular methods, including reverse transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Human noroviruses are genetically and antigenically diverse, with two main genogroups that are further subdivided into over 40 different genotypes. During the past decade, genogroup 2 genotype 4 (GII.4) has dominated in most countries, but recently, viruses belonging to GII.17 have increased in prevalence in a number of countries. A number of commercially available ELISAs and lateral flow immunoassays were found to have lower sensitivities to the GII.17 viruses, indicating that the antibodies used in these methods may not have a high level of cross-reactivity. In this study, we developed a rapid Nanobody-based lateral flow immunoassay (Nano-immunochromatography [Nano-IC]) for the detection of human norovirus in clinical specimens. The Nano-IC assay detected virions from two GII.4 norovirus clusters, which included the current dominant strain and a novel variant strain. The Nano-IC method had a sensitivity of 80% and specificity of 86% for outbreak specimens. Norovirus virus-like particles (VLPs) representing four genotypes (GII.4, GII.10, GII.12, and GII.17) could be detected by this method, demonstrating the potential in clinical screening. However, further modifications to the Nano-IC method are needed in order to improve this sensitivity, which may be achieved by the addition of other broadly reactive Nanobodies to the system. IMPORTANCE We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical setting, the Nano-IC assay had sensitivities equivalent to other commercially available lateral flow systems. The Nano-IC method was capable of producing results in ~5 min, which makes this method useful in settings that require rapid diagnosis, such as cruise ship outbreaks and elder care facilities. The Nano-IC assay has several advantages over antibody-based IC methods: for example, Nanobodies can be readily produced in large quantities, they are generally more stable than conventional antibodies, and the Nanobody binding sites can be easily obtained by X-ray crystallography.
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Respiratory viruses are a cause of upper respiratory tract infections (URTI), but can be associated with severe lower respiratory tract infections (LRTI) in immunocompromised patients. The objective of this study was to investigate the genetic variability of influenza virus, parainfluenza virus and respiratory syncytial virus (RSV) and the duration of viral shedding in hematological patients. Nasopharyngeal swabs from hematological patients were screened for influenza, parainfluenza and RSV on admission as well as on development of respiratory symptoms. Consecutive swabs were collected until viral clearance. Out of 672 tested patients, a total of 111 patients (17%) were infected with one of the investigated viral agents: 40 with influenza, 13 with parainfluenza and 64 with RSV; six patients had influenza/RSV or parainfluenza/RSV co-infections. The majority of infected patients (n = 75/111) underwent stem cell transplantation (42 autologous, 48 allogeneic, 15 autologous and allogeneic). LRTI was observed in 48 patients, of whom 15 patients developed severe LRTI, and 13 patients with respiratory tract infection died. Phylogenetic analysis revealed a variety of influenza A(H1N1)pdm09, A(H3N2), influenza B, parainfluenza 3 and RSV A, B viruses. RSV A was detected in 54 patients, RSV B in ten patients. The newly emerging RSV A genotype ON1 predominated in the study cohort and was found in 48 (75%) of 64 RSV-infected patients. Furthermore, two distinct clusters were detected for RSV A genotype ON1, identical RSV G gene sequences in these patients are consistent with nosocomial transmission. Long-term viral shedding for more than 30 days was significantly associated with prior allogeneic transplantation (p = 0.01) and was most pronounced in patients with RSV infection (n = 16) with a median duration of viral shedding for 80 days (range 35-334 days). Long-term shedding of respiratory viruses might be a catalyzer of nosocomial transmission and must be considered for efficient infection control in immunocompromised patients.
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Infección Hospitalaria/epidemiología , Infección Hospitalaria/virología , Enfermedades Hematológicas/virología , Esparcimiento de Virus , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Control de Enfermedades Transmisibles , Femenino , Genotipo , Humanos , Gripe Humana/virología , Masculino , Persona de Mediana Edad , Mutación , Nariz/virología , Orthomyxoviridae/metabolismo , Virus de la Parainfluenza 3 Humana/metabolismo , Infecciones por Paramyxoviridae/virología , Filogenia , Reacción en Cadena de la Polimerasa , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitiales Respiratorios/metabolismo , Estudios Retrospectivos , Análisis de Secuencia de ADN , Factores de Tiempo , Trasplante Homólogo , Adulto JovenRESUMEN
Respiratory syncytial virus (RSV) is the leading cause of hospitalization especially in young children with respiratory tract infections (RTI). Patterns of circulating RSV genotypes can provide a better understanding of the molecular epidemiology of RSV infection. We retrospectively analyzed the genetic diversity of RSV infection in hospitalized children with acute RTI admitted to University Hospital Heidelberg/Germany between October 2012 and April 2013. Nasopharyngeal aspirates (NPA) were routinely obtained in 240 children younger than 2 years of age who presented with clinical symptoms of upper or lower RTI. We analyzed NPAs via PCR and sequence analysis of the second variable region of the RSV G gene coding for the attachment glycoprotein. We obtained medical records reviewing routine clinical data. RSV was detected in 134/240 children. In RSV-positive patients the most common diagnosis was bronchitis/bronchiolitis (75.4%). The mean duration of hospitalization was longer in RSV-positive compared to RSV-negative patients (3.5 vs. 5.1 days; p<0.01). RSV-A was detected in 82.1%, RSV-B in 17.9% of all samples. Phylogenetic analysis of 112 isolates revealed that the majority of RSV-A strains (65%) belonged to the novel ON1 genotype containing a 72-nucleotide duplication. However, genotype ON1 was not associated with a more severe course of illness when taking basic clinical/laboratory parameters into account. Molecular characterization of RSV confirms the co-circulation of multiple genotypes of subtype RSV-A and RSV-B. The duplication in the G gene of genotype ON1 might have an effect on the rapid spread of this emerging RSV strain.
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Genotipo , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/genética , Estaciones del Año , Secuencia de Aminoácidos , Preescolar , Femenino , Alemania/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Datos de Secuencia Molecular , Filogenia , Virus Sincitial Respiratorio Humano/clasificación , Alineación de Secuencia , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genéticaRESUMEN
BACKGROUND: In recent years, scaling up of antiretroviral therapy (ART) in resource-limited settings moved impressively towards universal access. Along with these achievements, public health HIV programs are facing a number of challenges including the support of patients on lifelong therapy and the prevention of temporary/permanent loss of patients in care. Understanding reasons for treatment interruption (TI) can inform strategies for improving drug adherence and retention in care. OBJECTIVE: To evaluate key characteristics of patients resuming ART after TI at the Lighthouse Clinic in Lilongwe, Malawi, and to identify their reasons for interrupting ART. DESIGN: This study uses a mixed methods design to evaluate patients resuming ART after TI. We analysed an assessment form for patients with TI using pre-defined categories and a comments field to identify frequently stated reasons for TI. Additionally, we conducted 26 in-depth interviews to deepen our understanding of common reasons for TI. In-depth interviews also included the patients' knowledge about ART and presence of social support systems. Qualitative data analysis was based on a thematic framework approach. RESULTS: A total of 347 patients (58.2% female, average age 35.1±11.3 years) with TI were identified. Despite the presence of social support and sufficient knowledge of possible consequences of TI, all patients experienced situations that resulted in TI. Analysis of in-depth interviews led to new and distinct categories for TI. The most common reason for TI was travel (54.5%, n=80/147), which further differentiated into work- or family-related travel. Patients also stated transport costs and health-care-provider-related reasons, which included perceived/enacted discrimination by health care workers. Other drivers of TI were treatment fatigue/forgetfulness, the patients' health status, adverse drug effects, pregnancy/delivery, religious belief or perceived/enacted stigma. CONCLUSIONS: To adequately address patients' needs on a lifelong therapy, adherence-counselling sessions require provision of problem-solving strategies for common barriers to continuous care.
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Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/psicología , Cumplimiento de la Medicación/psicología , Adolescente , Adulto , Antirretrovirales/administración & dosificación , Antirretrovirales/efectos adversos , Continuidad de la Atención al Paciente , Femenino , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud , Estado de Salud , Humanos , Malaui , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Estigma Social , Apoyo Social , Factores Socioeconómicos , Transportes/economía , Adulto JovenRESUMEN
Nosocomial infection with respiratory syncytial virus (RSV) is an important health risk in pediatric care but is largely preventable by efficient infection control measures. Commonly applied rapid antigen detection tests (RADTs) miss a considerable number of RSV-infected patients. The objective of our analysis was to evaluate whether readily available host parameters are associated with false-negative RADT, and to assess how these parameters could be applied in an optimized RSV isolation strategy.We retrospectively analyzed a cohort of 242 children under the age of 2 years hospitalized with acute respiratory tract infection to identify host parameters associated with false-negative RADT test result. We subsequently simulated the outcome of different isolation strategies based on RADT result and host parameters in view of the overall isolation efficacy.Out of 242 hospitalized patients, 134 (55%) patients were found RSV-positive by RT-PCR, whereas 108 (45%) patients were tested negative. The performance of the RADT was compared with the result obtained by reverse transcription polymerase chain reaction on the identical nasopharyngeal wash. Overall, we found that 85 patients (35%) were tested true positive, 108 (45%) were tested true negative, whereas a false-negative test result was obtained in 49 patients (20%). Duration of respiratory symptoms for >3 days and a respiratory admission diagnosis are associated with false-negative RADT result. In comparison with RADT alone, consideration of these clinical parameters and RADT result can decrease the rate of nonisolated RSV-infected patients from approximately 24% to 8% (65% RSV pretest probability).Consideration of both RADT and clinical parameters associated with false-negative RADT can result in an optimized RSV infection control policy.
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Hospitalización , Aislamiento de Pacientes/métodos , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Infección Hospitalaria , Diagnóstico Diferencial , Reacciones Falso Negativas , Humanos , Lactante , Recién Nacido , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
INTRODUCTION: Enteroviruses commonly encounter babies and children and infections present in a wide variety of symptoms ranging from asymptomatic infection, benign illness, and aseptic meningitis, hand-foot-and-mouth disease to severe life-threatening disease. Some newborns develop severe disease in the first 2 weeks of life and long-term sequelae may occur among survivors. CASE PRESENTATION: We present a case report of a Caucasian newborn baby boy with severe encephalitis and systemic coxsackievirus B3 infection. The coincidence of maternal infection as well as previous mild respiratory illness in his sister suggests either prenatal or horizontal postnatal transmission. An electroencephalogram showed a severe pathologic pattern with theta-delta-rhythm and spike-wave complexes on both hemispheres. We also observed an unusual prolonged viremia for a period of 6 weeks. Due to the lack of specific antiviral treatment options, the supportive management included ventilation and medical treatment of seizures. Phylogenetic analysis revealed a genogroup D2 virus previously exclusively detected in China and now described in Europe for the first time. CONCLUSIONS: Enteroviral infection is an important differential diagnosis in neonatal encephalitis. Prolonged viremia must be taken into account and might correlate with disease severity. The newly observed enterovirus genotype D2 is spreading from Asia to other continents.