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1.
J Clin Virol ; 158: 105326, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36403314

RESUMO

BACKGROUND: To prevent spread to patients and co-workers, health care workers (HCWs) infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) should quickly be identified. Although real time polymerase chain reaction (RT-PCR) is the gold standard, this test takes several hours, during which a HCW is unable to work. Antigen (Ag) tests may be an efficacious means of screening HCWs since they are easy to perform and provide fast results. METHODS: In this study, 48,010 paired results of Ag-testing and RT-PCR, performed on HCWs between January 2021 and April 2022, were evaluated to determine the diagnostic accuracy of SARS-CoV-2 Ag-tests in diagnosing potentially infectious individuals. This analysis was performed with cycling threshold values (Ct-values) ≤30 and ≤25 as cut-offs. RESULTS: Respectively 3.1% (n = 1507) and 0.3% (n = 140) of Ag-tests were positive or indeterminate, and thus indicative for SARS-CoV-2 infection. In total, 2479 (5.2%) RT-PCRs were positive, of which 1529 (61.7%) had a Ct-value ≤25 and 402 (16.2%) a Ct-value between 26 and 30. At Ct-value ≤30 as a cut-off, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Ag-tests were 79.0%, 99.8%, 93.8% and 99.1%, respectively. At Ct-value ≤25, sensitivity further improved to 92.0%, by which the NPV increased to 99.7%. CONCLUSIONS: To prevent transmission from HCWs to patients and co-workers, while maintaining workforce capacity, Ag-tests are a valuable addition to RT-PCR tests, as they have a quick turnaround time and excellent sensitivity for identifying individuals with high potential for transmission.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pessoal de Saúde , Testes Imunológicos , Sensibilidade e Especificidade
2.
J Virol Methods ; 300: 114378, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34838535

RESUMO

BACKGROUND: Throughout the SARS-CoV-2 pandemic, a rapid identification of the virus was essential to quickly recognize positive cases and limit further spread by applying appropriate infection prevention. Many diagnostic laboratories use a multiplex Real-Time PCR assay, as they are not only highly sensitive but also specific. Currently, there are several assays and platforms in the market available which target different SARS-CoV-2 genes. The aim of this study was to validate and verify the GeneFinder™ COVID-19 PLUS RealAmp kit on the ELITe InGenius® instrument and compare to the national reference method. METHODS: GeneFinder™ COVID-19 PLUS RealAmp kit was evaluated against the routine WHO in- house Real-Time PCR assay, which is also the national reference method in the Netherlands and used in our laboratory. The sensitivity was tested using the analytical panel from Qnostics (Glasgow, United Kingdom) and the specificity was tested with patient material comprising of other seasonal respiratory viruses. In addition, 96 clinical samples initially analyzed by routine Real-Time PCR were tested using the GeneFinder™ COVID-19 PLUS RealAmp kit on the ELITe InGenius® instrument. RESULTS: The GeneFinder™ COVID-19 PLUS RealAmp kit had a similar performance compared to routine in-house testing, with a limit of detection of 500 dC/mL for the RdRp-gene and E gene. Meanwhile, the N gene showed a limit of detection of 50 dC/mL. The SARS-CoV-2 test was highly specific and detected no other respiratory viruses. The results of the clinical samples were comparable between both assays with similar Ct values observed for the in-house Real-Time-PCR and the GeneFinder™ COVID-19 PLUS RealAmp kit for the N gene. CONCLUSION: The GeneFinder™ COVID-19 PLUS RealAmp kit on the ELITe InGenius® instrument had an appropriate sensitivity and specificity that could be used in small scale laboratories or during night shifts where accurate diagnostics are crucial.


Assuntos
COVID-19 , Humanos , Pandemias , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2 , Sensibilidade e Especificidade
3.
J Clin Microbiol ; 57(1)2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30257900

RESUMO

The first World Health Organization (WHO) international standards (ISs) for nucleic acid amplification techniques were established two decades ago, with the initial focus on blood screening for three major viral targets, i.e., hepatitis C virus, hepatitis B virus, and human immunodeficiency virus 1. These reference materials have subsequently found utility in the diagnosis and monitoring of a wide range of infectious diseases in clinical microbiology laboratories worldwide. WHO collaborating centers develop ISs and coordinate international studies for their evaluation. The WHO Expert Committee on Biological Standardization is responsible for the endorsement of new standardization projects and the establishment of new and replacement ISs. Potencies of ISs are defined in international units (IU); the reporting in IU for assays calibrated with an IS (or secondary standards traceable to the IS) facilitates comparability of results for different assays and determination of assay parameters such as analytical sensitivities.


Assuntos
Laboratórios/normas , Técnicas de Amplificação de Ácido Nucleico/normas , Organização Mundial da Saúde , Humanos , Cooperação Internacional , Ácidos Nucleicos/química , Ácidos Nucleicos/genética , Padrões de Referência
5.
Transpl Int ; 30(8): 817-826, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28432714

RESUMO

Transplant recipients are prone to viral infections, which could affect renal transplantation outcome. Our aim was to assess the effects of early human cytomegalovirus (CMV) DNAemia on transplant renal function. A total of 264 (age 50.9 ± 13.5; male 55%) renal transplantation recipients undergoing preemptive anti-CMV therapy were retrospectively categorized based on early (<3 months post-Tx) CMV peak viral load (PVL); PVL ≤ 536, PVL536-6310, or PVL > 6310 International Units/ml (IU/ml). Estimated glomerular filtration rate (eGFR) was analyzed between 1 and 36 months post-transplantation with Kruskal-Wallis test, linear regression, and a linear mixed-effects model. CMV infection was detectable in 113 (43%) recipients within 49 [38-67] days. Subjects with PVL > 6310 had statistically significant ~5-13 ml/min lower eGFR between 3 and 36 months compared to PVL ≤ 536 and PVL536-6310. eGFR declined from 46.1 to 40.7 ml/min/1.73 m2 (-12%) over 3 years, and the annual decrease for pronounced infection with high PVL was 2.0 ml/min/1.73 m2 faster than for noninfected or mildly infected subjects. In conclusion, high CMV DNAemia early after renal transplantation was associated with significant loss of renal function, from which subjects did not recover. The severity of infection (high PVL early post-transplantation), more than the infection per se, was related to irreversible and progressive loss of renal function.


Assuntos
Infecções por Citomegalovirus/etiologia , Citomegalovirus/genética , DNA Viral/sangue , DNA Viral/genética , Transplante de Rim/efeitos adversos , Adulto , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/virologia , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Carga Viral , Viremia/sangue , Viremia/etiologia , Viremia/virologia
6.
Clin Microbiol Infect ; 23(9): 667-671, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28285979

RESUMO

OBJECTIVES: Hepatitis E virus (HEV) genotype 3 is endemic in Europe and an underdiagnosed and emerging (public) health issue. In recent years commercial enzyme immunoassays (EIAs) that detect antibodies to HEV more adequately, became available. We investigated the added value of this HEV serology in the diagnostic work flow to detect viral causes of recent hepatitis. METHODS: During a 2-year period (May 2013 to May 2015), HEV serology was added to the hepatitis work flow, consisting of serological detection of hepatitis viruses A, B and C (HAV, HBV, HCV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Samples positive for HEV IgM were also analysed using PCR to detect HEV RNA. If positive, HEV sequencing was performed for genotyping purposes. RESULTS: In 235 out of 2521 patients (9.3%), a viral cause for hepatitis was found. Recent HAV, HBV, HCV, EBV or CMV infections were serologically diagnosed in 3, 34, 10, 69 and 42 patients, respectively. Seventy-eight patients (3.1%) had a recent HEV infection. In 49 of them, sufficient HEV RNA was present for genotyping. All patients were infected with HEV genotype 3. CONCLUSIONS: In our region, an HEV infection is the most frequently diagnosed viral cause for recent hepatitis. These results indicate that, in a country where HEV is endemic, serological HEV diagnostics should be added to the standard work-up for viral hepatitis.


Assuntos
Vírus da Hepatite E , Hepatite E , Técnicas de Diagnóstico Molecular , Tipagem Molecular , Adolescente , Adulto , Idoso , Criança , Feminino , Hepatite E/diagnóstico , Hepatite E/epidemiologia , Hepatite E/virologia , Vírus da Hepatite E/classificação , Vírus da Hepatite E/genética , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/estatística & dados numéricos , Tipagem Molecular/métodos , Tipagem Molecular/estatística & dados numéricos , Países Baixos/epidemiologia , Valor Preditivo dos Testes , Estudos Soroepidemiológicos , Adulto Jovem
7.
J Clin Virol ; 58(2): 422-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23938304

RESUMO

BACKGROUND: Human herpesvirus-6 (HHV-6) frequently reactivates in immunocompromized individuals. Most commonly HHV-6 DNA is detected without organ localized disease. This HHV-6 DNAemia usually occurs in patients who also have CMV reactivations. The question if reactivation of one virus causes reactivation of the other, or whether both viruses reactivate independently, cannot be answered in populations with high seroprevalence for both viruses. Our study is the first in which 35 patients have been included who were CMV seronegative prior to transplantation. OBJECTIVE: We investigated the occurrence of HHV-6 reactivations in relation to the CMV-serostatus of renal transplantation donor and recipient. STUDY DESIGN: 9 consecutive patients receiving a renal transplantation were included. All available stored whole blood samples were tested for HHV-6 DNA by quantitative PCR. Details including CMV serostatus of donor and recipient were recorded. RESULTS: CMV-seropositive recipients have a 68% chance of developing HHV-6 DNAemia if the kidney came from a CMV-seropositive donor, compared to 26% if the kidney came from a CMV-seronegative donor. CMV-seronegative recipients, who are bound to undergo primary CMV infections following transplantation with a renal graft from a CMV-seropositive donor, have 88% chance of developing HHV-6 DNAemia. If they receive a graft from a CMV-seronegative donor the chance of developing HHV-6 DNAemia is 22%. CONCLUSION: Receiving a renal transplant from a CMV-seropositive donor increases the chance of developing HHV-6 DNAemia. HHV-6 DNAemia is a sign of impending primary CMV infections following sero-discordant renal transplantations.


Assuntos
Infecções por Citomegalovirus/epidemiologia , DNA Viral/sangue , Herpesvirus Humano 6/isolamento & purificação , Hospedeiro Imunocomprometido , Transplante de Rim , Infecções por Roseolovirus/virologia , Ativação Viral , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral , Viremia/virologia , Adulto Jovem
8.
J Clin Virol ; 58(1): 245-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23880160

RESUMO

BACKGROUND: Sequence based information is increasingly used to study the epidemiology of viruses, not only to provide insight in viral evolution, but also to understand transmission patterns during outbreaks. However, sequence analysis is not yet routinely performed by diagnostic laboratories, limiting its use in clinical practice. OBJECTIVES: To describe the added value of sequence based information available within 3 days after the detection of norovirus in fecal samples of patients and personnel during a suspected outbreak on a hospital ward. Results were used to guide the implementation of appropriate infection control measures, in particular closure of the ward. STUDY DESIGN: Observational study. RESULTS: Norovirus infection was detected in seven patients and two health care workers on an oncology ward of the children's hospital. Six of seven patients had a hospital acquired infection defined as a first day of illness more than two days after admission. After notification of the first two patients, supplementary infection control measures were taken to prevent further spread. Despite these measures, three additional patients with norovirus infection were identified. Characterization of the noroviruses of 5 out of 7 patients was available within 7 days after the notification of the first patient. Four different genotypes were detected, providing evidence for multiple introductions of different norovirus strains with only a few secondary cases rather than ongoing nosocomial transmission. Therefore, we maintained the already implemented infection control interventions without closure of the ward. CONCLUSIONS: Sequence based information available in real-time is helpful for understanding norovirus transmission in the hospital and facilitates appropriate infection control measures during an outbreak.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , RNA Viral/genética , Infecções por Caliciviridae/virologia , Análise por Conglomerados , Infecção Hospitalar/virologia , Fezes/virologia , Gastroenterite/virologia , Variação Genética , Genótipo , Humanos , Controle de Infecções , Epidemiologia Molecular , Norovirus/genética , Filogenia , Análise de Sequência de DNA
9.
Clin Microbiol Infect ; 19(10): E435-42, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23663244

RESUMO

Recent developments in molecular diagnostic tools have led to the easy and rapid detection of a large number of rhinovirus (HRV) strains. However, the lack of clinical and epidemiological data hampers the interpretation of these diagnostic findings. From October 2009 to January 2011, we conducted a prospective study in hospitalized children from whom samples were taken for the detection of respiratory viruses. Clinical, epidemiological and microbiological data from 644 patients with 904 disease episodes were collected. When HRV tested positive, strains were further characterized by sequencing the VP4/VP2 region of the HRV genome. HRV was the single respiratory virus detected in 254 disease episodes (28%). Overall, 99 different serotypes were detected (47% HRV-A, 12% HRV-B, 39% HRV-C). Patients with HRV had more underlying pulmonary illness compared with patients with no virus (p 0.01), or patients with another respiratory virus besides HRV (p 0.007). Furthermore, cough, shortness of breath and a need for oxygen were significantly more present in patients with HRV infection. Particularly, patients with HRV-B required extra oxygen. No respiratory symptom, except for oxygen need, was predictive of the presence of HRV. In 22% of HRV-positive disease episodes, HRV infection was hospital acquired. Phylogenetic analysis revealed several clusters of HRV; in more than 25% of these clusters epidemiological information was suggestive of transmission within specific wards. In conclusion, the detection of HRV may help in explaining respiratory illness, particular in patients with pulmonary co-morbidities. Identifying HRV provides opportunities for timely implementation of infection control measures to prevent intra-hospital transmission.


Assuntos
Infecção Hospitalar/virologia , Infecções por Picornaviridae/virologia , Rhinovirus/isolamento & purificação , Pré-Escolar , Infecção Hospitalar/epidemiologia , Feminino , Hospitalização , Humanos , Lactente , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Países Baixos/epidemiologia , Filogenia , Infecções por Picornaviridae/epidemiologia , Estudos Prospectivos , Rhinovirus/genética
10.
Infection ; 41(1): 77-91, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22847627

RESUMO

INTRODUCTION: Since acute respiratory tract infections inflict a high burden of disease in children worldwide, a multiplex reverse transcription polymerase chain reaction combined with a microwell hybridization assay (m-RT-PCR-ELISA) to detect 19 different respiratory pathogens was developed and validated. METHODS: A total of 430 respiratory specimens were retrospectively tested in parallel by both the advanced 19-valent m-RT-PCR-ELISA as well as by culture or individual RT-PCR assays used in clinical routine. RESULTS: The mean (median) sensitivity of the m-RT-PCR-ELISA in the retrospective test was 93.3% (95.1%; range 83.3-100 %), and the mean (median) specificity was 99.8 and 100 % (range 98.6-100 %), respectively. The mean positive predictive value was 99.3 % (range 93.4-100 %) and the mean negative predictive value was 95.3 % (range 98.4-100 %). Feasibility and clinical value of the 19-valent method was prospectively shown on 16,231 incoming clinical specimens from patients between 0 and 16 years of age with acute respiratory tract infections admitted to pediatric hospitals or private practices from October 2003 to June 2010 in three regions in Germany (Kiel, Mainz, Freiburg; Freiburg to June 2007 only). At least one microorganism was detected in 10,765 of 16,231 (66.3 %) clinical specimens: 5,044 RV, 1,999 RSV, 1,286 AV, 944 EV, 737 seasonal IVA, 173 pandemic IVA H1N1-2009, 899 MPV, 518 CV, 383 PIV3, 268 PIV1, 259 Mpn, 205 IVB, 164 PIV2, 144 PIV4, 103 Bp, 29 Cpn and 29 Bpp, while reovirus and Lpn were not present in these specimens from a pediatric population. More than one organism could be detected in 13.4 % of the specimens. CONCLUSIONS: The m-RT-PCR-ELISA evaluated here improves the spectrum for diagnosing respiratory infections and is a feasible instrument for individual diagnostic and epidemiological studies.


Assuntos
Ensaio de Imunoadsorção Enzimática , Reação em Cadeia da Polimerase Multiplex , Infecções Respiratórias/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Humanos , Vigilância da População , Reprodutibilidade dos Testes , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Sensibilidade e Especificidade
11.
J Clin Virol ; 54(2): 135-40, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22398034

RESUMO

BACKGROUND: Comparative data on severity and treatment of seasonal, pandemic and post-pandemic influenza virus infections are scarce. OBJECTIVES: To systematically analyze characteristics of hospitalized patients with influenza in the post-pandemic period compared to seasonal and pandemic influenza. STUDY DESIGN: Clinical and virological data of patients hospitalized in a tertiary referral hospital with post-pandemic influenza (2010-2011) were compared with those during seasonal influenza epidemics (2007-2009) and the influenza A(H1N1)pdm09 pandemic (2009-2010). RESULTS: 82 patients were admitted during the post-pandemic period, compared to 85 during the pandemic and 60 during seasonal influenza epidemics. No differences were observed in the occurrence of complicated illness and the need for intensive care. However, radiographic pneumonia was significantly more often diagnosed in patients with influenza A(H1N1)pdm09 compared to patients with seasonal influenza A (25% versus 71% in pandemic, p=0.004, and 55% in post-pandemic, p=0.047). Oseltamivir was more frequently prescribed in post-pandemic and pandemic patients compared to previous influenza seasons (48.9% resp. 76.5% versus 6.5%, p<0.0001). During the post-pandemic period, patients with influenza B were significantly less often treated with oseltamivir compared to patients with influenza A (27.0% versus 48.9%, p=0.043), although the course of illness in patients with influenza B was comparable with influenza A. No upsurge of oseltamivir resistance was observed. CONCLUSIONS: In our center, severity of illness was comparable for all influenza seasons, although more radiographic pneumonia was diagnosed in patients with influenza A(H1N1)pdm09. Despite the increased use of oseltamivir, no increase in oseltamivir resistance was detected.


Assuntos
Influenza Humana/patologia , Influenza Humana/virologia , Orthomyxoviridae/classificação , Orthomyxoviridae/patogenicidade , Adolescente , Adulto , Antivirais/administração & dosagem , Farmacorresistência Viral , Feminino , Humanos , Influenza Humana/complicações , Influenza Humana/tratamento farmacológico , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Orthomyxoviridae/efeitos dos fármacos , Orthomyxoviridae/isolamento & purificação , Oseltamivir/administração & dosagem , Pneumonia/diagnóstico , Pneumonia/epidemiologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
12.
J Infect Dis ; 204(5): 777-82, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21844304

RESUMO

A retrospective nationwide study on the use of intravenous (IV) zanamivir in patients receiving intensive care who were pretreated with oseltamivir in the Netherlands was performed. In 6 of 13 patients with a sustained reduction of the viral load, the median time to start IV zanamivir was 9 days (range, 4-11 days) compared with 14 days (range, 6-21 days) in 7 patients without viral load reduction (P = .052). Viral load response did not influence mortality. We conclude that IV zanamivir as late add-on therapy has limited effectiveness. The effect of an immediate start with IV zanamivir monotherapy or in combination with other drugs need to be evaluated.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana/tratamento farmacológico , Zanamivir/uso terapêutico , Adolescente , Adulto , Pré-Escolar , Estado Terminal , Quimioterapia Combinada , Humanos , Lactente , Infusões Intravenosas , Pessoa de Meia-Idade , Países Baixos , Oseltamivir/uso terapêutico , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Carga Viral , Zanamivir/administração & dosagem
13.
Antimicrob Agents Chemother ; 54(3): 1283-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20065049

RESUMO

Hepatitis B virus (HBV) antiviral drug resistance mutations prevent successful outcome of treatment and lead to worsening of liver disease. Detection of its emergence permits opportune treatment with alternative drugs. Unfortunately, the use of newly approved antivirals, including adefovir dipivoxil, emtricitabine, and telbivudine, is also associated with the development of drug resistance, albeit to a lesser extent than the use of lamivudine. The objectives of this work were to assess the performance characteristics (sensitivity and accuracy) of an updated drug resistance test, the INNO-LiPA HBV DR v2, which includes detection of mutations associated with lamivudine, adefovir, emtricitabine, and telbivudine resistance, and to compare the results with consensus sequencing of serum samples from patients treated with HBV antivirals. Diagnostic sensitivity, defined as detection of a positive amplification line on the line probe assay (LiPA) strip, was 94.8% (95% confidence interval [CI], 89.7 to 97.9) after initial testing, increasing to 96.3% (95% CI, 91.6 to 98.8) after repeat test 1 and to 100% (95% CI, 97.3 to 100.0) after repeat test 2. In diagnostic accuracy determinations, full concordance was observed between sequencing and LiPA for 77.0% of the codons tested (620/805 codons [95% CI, 74.0 to 79.9]), whereas LiPA and sequencing were partially concordant 22% of the time (177/805 codons). In 167 out of 177 cases, LiPA detected a wild-type/mutant mixture whereas sequencing detected only one of the two results. Performance testing of the new LiPA test, the INNO-LiPA HBV DR v2, showed convincing diagnostic sensitivity and accuracy. The ability of the test to detect mixed infections and minority viral populations associated with resistance to the current generation of antivirals, including adefovir, emtricitabine, and telbivudine, makes it a useful tool for HBV therapy monitoring.


Assuntos
Antivirais/farmacologia , Monitoramento de Medicamentos/métodos , Farmacorresistência Viral/genética , Vírus da Hepatite B/efeitos dos fármacos , Hibridização de Ácido Nucleico/métodos , Nucleosídeos/farmacologia , Antivirais/química , Antivirais/uso terapêutico , DNA Viral/sangue , Hepatite B/tratamento farmacológico , Hepatite B/virologia , Vírus da Hepatite B/genética , Humanos , Testes de Sensibilidade Microbiana , Mutação , Nucleosídeos/química , Nucleosídeos/uso terapêutico , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA
14.
Clin Microbiol Infect ; 14(12): 1173-6, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19046164

RESUMO

The performance of nucleic acid amplification techniques for detecting respiratory syncytial virus (RSV) was evaluated in 25 laboratories across Europe by an external quality assessment study. In addition, factors related to the diagnostic performance of laboratories were explored. The results of this quality control study show that the performance of laboratories for RSV diagnosis in Europe is good, with an overall correct score of 88%. The type of assay (nested or real-time PCR vs. commercial tests) was identified as a significant factor (OR 8.39; 95% CI 1.91-36.78) in predicting a correct result.


Assuntos
Pesquisa sobre Serviços de Saúde , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sinciciais Respiratórios/isolamento & purificação , Europa (Continente) , Humanos , Vírus Sinciciais Respiratórios/genética
15.
Ned Tijdschr Geneeskd ; 152(25): 1426-30, 2008 Jun 21.
Artigo em Holandês | MEDLINE | ID: mdl-18624006

RESUMO

OBJECTIVE: To assess the usefulness of a simple practical guideline based on hepatitis B e-antigen (HBeAg) status and a single alanine aminotransferase (ALT) determination to predict hepatitis B virus (HBV) load in chronic HBV patients as a criterion for referral to a specialist for possible antiviral therapy. DESIGN: Prospective observational study. METHOD: 420 patients with chronic HBV infection were seen at the Municipal Health Service (MHS) in Rotterdam between 2002 and 2005. The usefulness ofa guideline based on HBeAg positivity and/or elevated ALT levels to predict high HBV DNA levels (defined as more than 10(5) copies/ml) was determined. Patients with HBeAg or an elevated ALT level were referred to a specialist according to the practical guideline. Positive and negative predictive value, sensitivity, and specificity of the referral guideline for a high HBV-DNA level were calculated. RESULTS: Less than half, 43% (181/420) of the patients, were eligible for referral to specialist care. The positive predictive value of the referral guideline was 45% (82/181, 95% CI: 38-53). The negative predictive value, i.e. the proportion of patients with low viral loads who were (rightly) not selected for referral, was 95% (227/239; 95% CI: 71-97). The sensitivity was 87% (95% CI: 80-93): the patients selected included 82 of 94 patients with a high HBV DNA level. Of the 12 patients with high viral loads not referred according to the guideline, 11 had a viral load of between 10(5)-10(6) copies/ml. CONCLUSION: A referral guideline based on HBeAg status and a single ALT determination can successfully predict viral load in chronic HBV patients and can be used in primary care to select patients for referral to specialist care. This guideline may limit the number of unnecessarily referred patients, enhancing the efficiency of the care for patients with chronic HBV infection.


Assuntos
Alanina Transaminase/sangue , Antivirais/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/sangue , Guias de Prática Clínica como Assunto , Encaminhamento e Consulta , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Criança , DNA Viral/análise , Feminino , Hepatite B Crônica/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Carga Viral
16.
Clin Microbiol Infect ; 14(7): 677-84, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18558940

RESUMO

In order to evaluate the infectious agents associated with the first episode of severe acute wheezing in otherwise healthy infants and to define the role of each of them in recurrences, 85 patients in Italy, aged <12 months, hospitalized because of a first acute episode of wheezing, were prospectively enrolled between 1 October 2005 and 31 March 2006. Upon enrollment, nasopharyngeal swabs were collected for the real-time PCR detection of respiratory syncytial virus (RSV) types A and B, influenza virus types A and B, adenovirus, parainfluenza viruses types 1, 2, 3 and 4, rhinovirus, human metapneumovirus, human coronavirus types 229E, OC43, NL63, and HKU1, bocavirus, enterovirus, and paraechovirus; nasopharyngeal aspirates were also obtained to detect atypical bacteria. At least one infectious agent was identified in 76 children (89.4%). RSV was the most frequently detected pathogen and its prevalence was significantly higher than that of the other pathogens in both age groups, and significantly higher in the children aged 3-12 months than in those aged <3 months. Only the children with RSV infection experienced recurrent wheezing. Viral load was significantly higher in children with than in those without recurrent wheezing. This study shows that RSV is the main reason for hospitalization during the first wheezing episode in infants, and that it appears to be the only pathogen associated with a high frequency of recurrences. A high viral load seems to be strictly related to the likelihood of recurrence.


Assuntos
Sons Respiratórios/etiologia , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sincicial Respiratório Humano/isolamento & purificação , Formas Bacterianas Atípicas/isolamento & purificação , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/epidemiologia , Hospitalização , Humanos , Lactente , Recém-Nascido , Itália , Prevalência , Estudos Prospectivos , Recidiva , Infecções por Vírus Respiratório Sincicial/epidemiologia , Carga Viral
17.
J Clin Virol ; 42(2): 194-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18359662

RESUMO

BACKGROUND: We cannot predict when an influenza pandemic will occur or which variant of the virus will cause it. Little information is currently available on the ability of laboratories to detect and subtype influenza viruses including the avian influenza viruses. OBJECTIVES: To assess the ability of laboratories to detect and subtype influenza viruses. STUDY DESIGN: In 2006 QCMD distributed an External Quality Assessment panel for the molecular detection and haemagglutinin subtyping of influenza viruses to 87 laboratories in 34 countries Worldwide, which were given 6 weeks to return results. These data were analysed to assess laboratory performance. RESULTS: Influenza virus positive panel samples were correctly identified by 35-98% of laboratories. The correct haemagglutinin subtype was reported by 32-87% of laboratories that detected the virus: incorrect subtyping results included the reporting of avian influenza viruses as human strains and vice versa. Twelve laboratories reported false positives with some avian influenza viruses reported. CONCLUSIONS: These data suggest that improvements are needed in the molecular detection of influenza viruses and influenza virus A haemagglutinin subtyping. Only rapid and accurate identification of circulating pandemic influenza virus will ensure that the maximum time is available for intervention.


Assuntos
Surtos de Doenças , Vírus da Influenza A , Vírus da Influenza B , Influenza Humana , Laboratórios/normas , Animais , Reações Falso-Positivas , Saúde Global , Glicoproteínas de Hemaglutininação de Vírus da Influenza/classificação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/classificação , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Influenza Humana/virologia , Controle de Qualidade , Padrões de Referência , Carga Viral
18.
J Viral Hepat ; 15(2): 108-14, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18184193

RESUMO

The nucleotide analogues, tenofovir disoproxil fumarate and adefovir dipivoxil, inhibit viral replication and are both effective against the hepatitis B virus (HBV). In our department, tenofovir was prescribed in addition to lamivudine for the treatment of lamivudine resistant chronic hepatitis B. After registration of adefovir, 10 patients were switched to adefovir monotherapy. We studied changes in HBV-DNA and alanine aminotransferase (ALT) in these patients. The median treatment duration with tenofovir was 78 weeks resulting in a median viral load reduction of 5.4 (range 6.8-2.3) log(10) copies/mL compared to baseline (P = 0.005). Two patients had an increase >1 log(10) copies/mL during tenofovir treatment. After the switch to adefovir, six out of 10 patients had an HBV-DNA >4 log(10) copies/mL and the median HBV-DNA increased from 2.8 to 4.5 log(10) copies/mL (P = 0.017). The factors associated with relapse were HBV-DNA PCR positivity at the time of switch and genotype B or D. ALT levels at the beginning of tenofovir treatment also might be a factor. Retreatment with tenofovir (n = 3) resulted in a rapid decline in HBV-DNA. Tenofovir is a potent antiviral drug. Switching to adefovir resulted in viral relapse in 60% of patients and retreatment with tenofovir resulted again in viral decline, which suggests that tenofovir is a more potent antiviral agent.


Assuntos
Adenina/análogos & derivados , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Organofosfonatos/farmacocinética , Organofosfonatos/uso terapêutico , Carga Viral , Adenina/farmacocinética , Adenina/farmacologia , Adenina/uso terapêutico , Adolescente , Adulto , Antivirais/uso terapêutico , Estudos de Coortes , DNA Viral/efeitos dos fármacos , Farmacorresistência Viral , Feminino , Genótipo , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/metabolismo , Humanos , Lamivudina/farmacologia , Masculino , Pessoa de Meia-Idade , Organofosfonatos/farmacologia , Estudos Retrospectivos , Tenofovir , Replicação Viral/efeitos dos fármacos
19.
Ned Tijdschr Geneeskd ; 152(49): 2673-80, 2008 Dec 06.
Artigo em Holandês | MEDLINE | ID: mdl-19137968

RESUMO

OBJECTIVE: To gain insight into hepatitis B virus (HBV) transmission in the Netherlands. DESIGN: Descriptive. METHOD: During 2004, epidemiological data and blood samples (if available) were collected for all reported cases of acute HBV infections in the Netherlands. Following DNA isolation and amplification a 648 base pairs fragment of the HBV S gene was sequenced and subjected to phylogenetic analysis. The sequencing details were also linked to epidemiological information. RESULTS: In 2004, 291 cases ofacute HBV infections were reported. Blood samples were received from 171 patients (59%), and the genotype could be determined for 158 patients (54%). 6 genotypes were identified: A (64%), B (3%), C (3%), D (21%), E (5%) and F (4%). Of all patients with genotype A, 52% had been infected via homosexual or bisexual contact and 16% via heterosexual contact. Of all patients with genotype D, 42% had been infected via heterosexual contact and 15% via homosexual or bisexual contact. The genotype A cluster was extremely homogeneous with many identical sequences, while genotype B-E clusters were more heterogeneous. 4 identical sequences were found within genotype F, but the patients could not be epidemiologically linked. CONCLUSION: Sexual transmission, particularly via homosexual or bisexual contact in men, formed the most important risk factor for acquiring an acute HBV infection. Genotype A was predominant in the Netherlands, especially among homosexual or bisexual men. Most infections within genotype D occurred as a result of heterosexual contact. The results show that there was ongoing transmission of HBV in homosexual or bisexual men, while in heterosexuals more cases of new introduction were seen, possibly via chronic carriers from areas where HBV is endemic.

20.
J Med Virol ; 79(12): 1868-76, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17935176

RESUMO

Several real-time PCR and nucleic acid sequence-based amplification (NASBA) primer pairs and a modified real-time PCR primer pair for the detection of enteroviruses were compared. The modified real-time PCR primer pair was evaluated on clinical samples in comparison with cell culture using the MagnaPure LC Isolation instrument for nucleic acid extraction. Six hundred forty samples could be examined both by cell culture and real-time PCR. Faecal specimens (n = 285), cerebrospinal fluid (n = 210), throat swabs (n = 113), biopsies (n = 1--, vesicular fluid (n = 11), and pleural fluid specimens (n = 9) were included. By culture, 26/640 (4%) samples were positive for enterovirus. By real-time PCR, the number of positive specimens was 50 (7.8%). Of the 210 cerebrospinal fluid samples, three were positive by culture and nine by real-time PCR. Seventeen and 33 of a total of 285 faecal specimens were positive by culture and real-time PCR, respectively. In case of discrepant results, the clinical symptoms were in accordance with an infection due to enteroviruses. Genotyping using the VP1 gene correlated with serotyping by neutralization. In contrast, six of the 19 specimens that could be typed both by neutralization and by sequencing using the VP4 domain yielded a different genotype, yet within the same species. Real-time PCR turned out to be suitable for the detection of enteroviruses in the daily routine setting. In comparison to rapid culture, it offers a rapid, more sensitive, and reliable assay; especially in cerebrospinal fluid, the yield of enteroviruses is much higher.


Assuntos
Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/virologia , Enterovirus/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Cultura de Vírus/métodos , Enterovirus/genética , Enterovirus/crescimento & desenvolvimento , Infecções por Enterovirus/líquido cefalorraquidiano , Fezes/virologia , Humanos , Rhinovirus/genética , Rhinovirus/crescimento & desenvolvimento , Rhinovirus/isolamento & purificação , Sensibilidade e Especificidade
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