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Journal ArticleDOI

Rapid diagnostic tests for identifying avian influenza A(H7N9) virus in clinical samples.

01 Jan 2015-Emerging Infectious Diseases (Centers for Disease Control and Prevention)-Vol. 21, Iss: 1, pp 87-90

TL;DR: To determine sensitivity of rapid diagnostic tests for detecting influenza A(H7N9) virus, this work compared rapid tests with PCR results and tested different types of clinical samples.

AbstractTo determine sensitivity of rapid diagnostic tests for detecting influenza A(H7N9) virus, we compared rapid tests with PCR results and tested different types of clinical samples. Usefulness of seasonal influenza rapid tests for A(H7N9) virus infections is limited because of their low sensitivity for detecting virus in upper respiratory tract specimens.

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Citations
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Journal ArticleDOI
TL;DR: The results of this study indicate that the proposed simple strategy using an intensity-modulated surface plasmon resonance (IM-SPR) biosensor integrated with a new generated monoclonal antibody demonstrates high sensitivity and time-saving in H7N9 virus detection.
Abstract: In 2013 a new reassortant avian influenza A H7N9 virus emerged in China, causing human infection with high mortality. An accurate and timely diagnosis is crucial for controlling the outbreaks of the disease. We therefore propose a simple strategy for rapidly and sensitively detecting the H7N9 virus using an intensity-modulated surface plasmon resonance (IM-SPR) biosensor integrated with a new generated monoclonal antibody. The novel antibody exhibits significant specificity to recognize H7N9 virus compared with other clinical human influenza isolates (p < 0.01). Experimentally, the detection limit of the proposed approach for H7N9 virus detection is estimated to be 144 copies/mL, which is a 20-fold increase in sensitivity compared with homemade target-captured ELISA using the identical antibody. For the measurement of mimic clinical specimens containing the H7N9 virus mixed with nasal mucosa from flu-like syndrome patients, the detection limit is calculated to be 402 copies/mL, which is better than conven...

53 citations


Journal ArticleDOI
TL;DR: Novel monoclonal antibodies against influenza A H7N9 recombinant hemagglutinin (rHA)1 were developed and applied to a Europium nanoparticle–based rapid fluorescent immunochromatographic strip test (FICT) to improve the sensitivity of the rapid diagnostic system.
Abstract: The development of a sensitive and rapid diagnostic test is needed for early detection of avian influenza (AI) H7 subtype. In this study, novel monoclonal antibodies (mAbs) against influenza A H7N9 recombinant hemagglutinin (rHA)1 were developed and applied to a Europium nanoparticle–based rapid fluorescent immunochromatographic strip test (FICT) to improve the sensitivity of the rapid diagnostic system. Two antibodies (2F4 and 6D7) exhibited H7 subtype specificity in a dot-FICT assay by optimization of the conjugate and the pH of the lysis buffer. The subtype specificity was confirmed by an immunofluorescence assay and Western blot analysis. The limit of detection of the FICT employing novel mAbs 31 ng/mL for H7N9 rHA1 and 40 hemagglutination units/mL for H7 subtype virus. Sensitivity was improved 25-fold using Europium as confirmed by comparison of colloidal gold-based rapid diagnostic kit using the 2F4 and 6D7 mAbs.

24 citations


Journal ArticleDOI
TL;DR: Early NAI therapy within 2 days of illness shortened the duration of viral shedding and improved survival in patients with H7N9 viral infection.
Abstract: Background The significance of early neuraminidase inhibitor (NAI) therapy for treating influenza A(H7N9) is currently unknown. Methods The duration of viral shedding was monitored by reverse-transcription polymerase chain reaction after patients with confirmed H7N9 infection were admitted to the First Affiliated Hospital, Zhejiang University, during April 2013-April 2017. Indices such as the length of hospitalization and mortality were collected, and the correlation between the time of administration of NAI and the severity of disease was systematically analyzed. Results One hundred sixty patients with confirmed H7N9 infection were divided into 3 groups according to NAI starting time. Three of 20 (15%) patients for whom NAI was administered within 2 days died compared with 12 of 52 (23.1%) patients who received treatment within 2-5 days and 33 of 88 (37.5%) patients who were treated after 5 days (P < .05). The median durations of viral shedding from NAI therapy initiation was 4.5 days (interquartile range [IQR], 3-9 days) for patients who took antiviral medication within 2 days, which was significantly different from that for patients who took medication within 2-5 days (7.5 days [IQR, 4.25-12.75 days]) or after 5 days (7 days [IQR, 5-10 days]) (P < .05). We found that the duration of viral shedding from NAI therapy was the shortest in spring 2013 (5.5 days) and the longest in winter-spring 2016-2017 (8.5 days) (P < .05), showing a prolonged trend. Conclusions Early NAI therapy within 2 days of illness shortened the duration of viral shedding and improved survival in patients with H7N9 viral infection.

22 citations


Cites background from "Rapid diagnostic tests for identify..."

  • ...First, the majority of H7N9 patients are farmers, who do not generally seek formal clinical treatment in a timely manner [19]....

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Journal ArticleDOI
TL;DR: The diagnosis of influenza A virus infections in poultry or wild birds is difficult due to variations in the pathogenicity of the viruses in different avian hosts and the antigenic and genetic diversity of the virus, particularly the recent H5 highly pathogenic avian influenza viruses.
Abstract: The diagnosis of influenza A virus infections in poultry or wild birds is difficult due to variations in the pathogenicity of the viruses in different avian hosts and also the antigenic and genetic diversity of the virus, particularly the recent H5 highly pathogenic avian influenza viruses A classical standard laboratory technique is virus isolation prior to subtyping and pathotyping This diagnostic technique is crucial for further virological analyses, particularly during an initial outbreak; however, delays in diagnosis have thwarted effective disease control in recent years Recent developments in molecular biological techniques provide an accelerated diagnosis Such technologies, which include real-time reverse transcriptase PCR, isothermal nucleic acid amplification, next-generation sequencing and immunochromatography, contribute to simpler and more rapid diagnosis The advantages of each of these diagnostic techniques should be considered for effective control of avian influenza

16 citations


Cites background from "Rapid diagnostic tests for identify..."

  • ...242 Because H7N9 LPAIV did not replicate in the respiratory tract and other organs of 243 chickens, the use of a rapid diagnostic test was limited in the field (Chen et al., 2015)....

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Journal ArticleDOI
TL;DR: The Red dye 53 could be a potential probe for rapid fluorescent diagnostic systems that can recognize AI virus in clinical specimens and was higher than that of fluorescein isothiocyanate (FITC), showing a stronger fluorescent signal persisting up to 8min under UV.
Abstract: Sensitive and rapid diagnostic systems for avian influenza (AI) virus are required to screen large numbers of samples during a disease outbreak and to prevent the spread of infection. In this study, we employed a novel fluorescent dye for the rapid and sensitive recognition of AI virus. The styrylpyridine phosphor derivative was synthesized by adding allyl bromide as a stable linker and covalently immobilizing it on latex beads with antibodies generating the unique Red dye 53-based fluorescent probe. The performance of the innovative rapid fluorescent immnunochromatographic test (FICT) employing Red dye 53 in detecting the AI virus (A/H5N3) was 4-fold and 16-fold higher than that of Europium-based FICT and the rapid diagnostic test (RDT), respectively. In clinical studies, the presence of human nasopharyngeal specimens did not alter the performance of Red dye 53-linked FICT for the detection of H7N1 virus. Furthermore, in influenza A virus-infected human nasopharyngeal specimens, the sensitivity of the Red dye 53-based assay and RDT was 88.89% (8/9) and 55.56% (5/9) relative to rRT-PCR, respectively. The photostability of Red dye 53 was higher than that of fluorescein isothiocyanate (FITC), showing a stronger fluorescent signal persisting up to 8min under UV. The Red dye 53 could therefore be a potential probe for rapid fluorescent diagnostic systems that can recognize AI virus in clinical specimens.

16 citations


References
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Journal ArticleDOI
TL;DR: Novel reassortant H7N9 viruses were associated with severe and fatal respiratory disease in three patients, and all three patients died.
Abstract: Background Infection of poultry with influenza A subtype H7 viruses occurs worldwide, but the introduction of this subtype to humans in Asia has not been observed previously. In March 2013, three urban residents of Shanghai or Anhui, China, presented with rapidly progressing lower respiratory tract infections and were found to be infected with a novel reassortant avian-origin influenza A (H7N9) virus. Methods We obtained and analyzed clinical, epidemiologic, and virologic data from these patients. Respiratory specimens were tested for influenza and other respiratory viruses by means of real-time reverse-transcriptase–polymerase-chain-reaction assays, viral culturing, and sequence analyses. Results A novel reassortant avian-origin influenza A (H7N9) virus was isolated from respiratory specimens obtained from all three patients and was identified as H7N9. Sequencing analyses revealed that all the genes from these three viruses were of avian origin, with six internal genes from avian influenza A (H9N2) virus...

1,985 citations


"Rapid diagnostic tests for identify..." refers background or methods in this paper

  • ...The specimens tested were throat swab or sputum (including tracheal aspirates) collected from patients with suspected A(H7N9) virus infection since late March 2013, confirmed by rRT-PCR with primers and probes described previously (1,3), and stored at –80°C....

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  • ...O March 31, 2013, in China, novel avian influenza A(H7N9) virus infection was diagnosed in 3 persons (1)....

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Journal ArticleDOI
TL;DR: The presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) during the evaluation period, and the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death.
Abstract: Background During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus. Methods Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013. Results Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%)...

565 citations


"Rapid diagnostic tests for identify..." refers background in this paper

  • ...Considering that most A(H7N9) virus–infected patients had pneumonia and that the virus replicates more efficiently in the lower respiratory tract than in the upper respiratory tract (6,7), A(H7N9) viral loads are probably higher in specimens from the lower respiratory tract....

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Journal ArticleDOI
25 Jul 2013-Nature
TL;DR: It is shown that the emerging H7N9 avian influenza virus poses a potentially high risk to humans, and current seasonal vaccination could not provide protection.
Abstract: Human infection associated with a novel reassortant avian influenza H7N9 virus has recently been identified in China. A total of 132 confirmed cases and 39 deaths have been reported. Most patients presented with severe pneumonia and acute respiratory distress syndrome. Although the first epidemic has subsided, the presence of a natural reservoir and the disease severity highlight the need to evaluate its risk on human public health and to understand the possible pathogenesis mechanism. Here we show that the emerging H7N9 avian influenza virus poses a potentially high risk to humans. We discover that the H7N9 virus can bind to both avian-type (α2,3-linked sialic acid) and human-type (α2,6-linked sialic acid) receptors. It can invade epithelial cells in the human lower respiratory tract and type II pneumonocytes in alveoli, and replicated efficiently in ex vivo lung and trachea explant culture and several mammalian cell lines. In acute serum samples of H7N9-infected patients, increased levels of the chemokines and cytokines IP-10, MIG, MIP-1β, MCP-1, IL-6, IL-8 and IFN-α were detected. We note that the human population is naive to the H7N9 virus, and current seasonal vaccination could not provide protection.

312 citations


"Rapid diagnostic tests for identify..." refers background in this paper

  • ...Considering that most A(H7N9) virus–infected patients had pneumonia and that the virus replicates more efficiently in the lower respiratory tract than in the upper respiratory tract (6,7), A(H7N9) viral loads are probably higher in specimens from the lower respiratory tract....

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Journal ArticleDOI
TL;DR: Children who had certain endothelial and immune function markers were more likely to survive infection and be diagnosed with infection later in life.
Abstract: Outbreaks of Ebola virus disease (EVD) occur sporadically in Africa and are associated with high case-fatality rates. Historically, children have been less affected than adults. The 2000–2001 Sudan virus–associated EVD outbreak in the Gulu district of Uganda resulted in 55 pediatric and 161 adult laboratory-confirmed cases. We used a series of multiplex assays to measure the concentrations of 55 serum analytes in specimens from patients from that outbreak to identify biomarkers specific to pediatric disease. Pediatric patients who survived had higher levels of the chemokine regulated on activation, normal T-cell expressed and secreted marker and lower levels of plasminogen activator inhibitor 1, soluble intracellular adhesion molecule, and soluble vascular cell adhesion molecule than did pediatric patients who died. Adult patients had similar levels of these analytes regardless of outcome. Our findings suggest that children with EVD may benefit from different treatment regimens than those for adults.

74 citations


Journal ArticleDOI
TL;DR: The results indicate that the detection sensitivity to swine origin H1N1 viruses varies widely among IRDTs, with some tests lacking sufficient sensitivity to detect the early stages of infection when the virus load is low.
Abstract: Simple and rapid diagnosis of influenza is useful for making treatment decisions in the clinical setting. Although many influenza rapid diagnostic tests (IRDTs) are available for the detection of seasonal influenza virus infections, their sensitivity for other viruses, such as H5N1 viruses and the recently emerged swine origin pandemic (H1N1) 2009 virus, remains largely unknown. Here, we examined the sensitivity of 20 IRDTs to various influenza virus strains, including H5N1 and 2009 pandemic H1N1 viruses. Our results indicate that the detection sensitivity to swine origin H1N1 viruses varies widely among IRDTs, with some tests lacking sufficient sensitivity to detect the early stages of infection when the virus load is low.

64 citations


Additional excerpts

  • ...A previous study also indicated that detection sensitivity for swine-origin A(H1N1) viruses varies widely among seasonal influenza A virus RDTs; some tests are unsuitable for detecting several subtypes of avian influenza viruses because of low sensitivity (8)....

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