scholarly journals Effectiveness of two rapid influenza tests in comparison to reverse transcription-PCR for influenza A diagnosis

2014 ◽  
Vol 8 (03) ◽  
pp. 331-338 ◽  
Author(s):  
Ramón Zazueta-García ◽  
Adrian Canizalez-Roman ◽  
Hector Flores-Villaseñor ◽  
Javier Martínez-Garcia ◽  
Alejandro Llausas-Vargas ◽  
...  

Introduction: The influenza A virus is responsible for high morbidity and mortality in children and adults worldwide. Thus, a rapid, sensitive, and specific diagnosis tool is required. Methodology: An immunofluorescence assay (DFA) and a lateral-flow immunochromatographic assay were compared with RT-PCR for detection of the influenza A virus in 113 nasopharyngeal wash samples obtained from pediatric patients. Samples were collected between July and December 2009, during the pandemic outbreak of influenza A H1N1/09. Results: The sensitivity, specificity, and positive and negative predictive values obtained for the DFA were 68.97%, 76.63%, 75.47%, and 70%, respectively, while the values obtained for the immunochromatographic assay were 58.62%, 81.82%, 77.27%, and 65.22%, respectively. The frequency of the influenza A virus was 51.33%, and a total of 27 samples were positive for the pandemic influenza A H1N1/09. Conclusions: DFA and the immunochromatographic assay can be important tools for patient care during influenza season and in outbreaks as they usually provide results within 45 minutes. Furthermore, positive results in conjunction with the patient’s symptoms could provide a correct diagnosis, thus facilitating appropriate patient management. Nonetheless, the results of these assays still require confirmation by RT-PCR.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Changzhong Jin ◽  
Nanping Wu ◽  
Xiaorong Peng ◽  
Hangping Yao ◽  
Xiangyun Lu ◽  
...  

We assessed a colloidal gold immunochromatographic assay (GICA) for rapid detection of influenza A (H7N9) and compared it with reverse-transcription-polymerase chain reaction (RT-PCR) and viral culture. Samples from 35 H7N9 infected patients were collected, including 45 throat swab samples, 56 sputum samples, and 39 feces samples. All samples were tested by GICA, viral culture, and RT-PCR. GICA specifically reacted with recombinant HA proteins, virus lysates, and clinical samples from H7 subtype viruses. Compared with RT-PCR, GICA demonstrated low sensitivity (33.33%) but high specificity (97.56%). The positive rate of GICA tests for samples collected in the period from 8 to 21 days after contact with poultry was much higher than those for samples collected before or after this period. Compared with viral culture, GICA showed sensitivity of 91.67% and specificity of 82.03%. Sputum specimens were more likely to test positive for H7N9 virus than samples from throat swabs and feces. The GICA-based H7 test is a reliable, rapid, and convenient method for the screening and diagnosis of influenza A (H7N9) disease, especially for the sputum specimens with high viral load. It may be helpful in managing H7N9 epidemics and preliminary diagnosis in early stages in resource-limited settings.


1998 ◽  
Vol 36 (3) ◽  
pp. 796-801 ◽  
Author(s):  
Geneviève Eugene-Ruellan ◽  
François Freymuth ◽  
Chokri Bahloul ◽  
Hassan Badrane ◽  
Astrid Vabret ◽  
...  

A reverse transcription-PCR and hybridization-enzyme immunoassay (RT-PCR-EIA) has been developed to identify the major agents of bronchiolitis in infants: respiratory syncytial viruses A and B (RSVA and RSVB) and parainfluenzavirus 3 (PIV3). Two primer sets (P1-P2 and P1-P3) were selected in a conserved region of the polymerase L gene. In infected cell cultures, this method detected RSVA (n = 14), RSVB (n = 13), and PIV3 (n = 13), with the exclusion of PIV1 (n = 4), PIV2 (n = 3), measles virus (n = 6), mumps virus (n = 4), influenza A virus (n = 11), and influenza B virus (n = 4). The differentiation of the amplicons by restriction fragment length polymorphism (RFLP) showed a PvuII site for PIV3 strains and an AvaII site for RSV strains, with RSVA distinguished from RSVB by BglII. The hybridization-EIA, using three internal probes specific for each virus, correlated with the immunofluorescence assay (IFA) and RFLP results. Clinical aspirates from 261 infants hospitalized with bronchiolitis were tested by IFA, viral isolation technique (VIT), and RT-PCR-EIA. RT-PCR-EIA detected RSV sequences in 103 samples (39.4%), and IFA-VIT detected RSV sequences in 109 cases (41.7%). A few samples (2.6%) were IFA-VIT positive but PCR negative, and one sample was RT-PCR-EIA positive only. RT-PCR-EIA detected PIV3 sequences in 14 of the 15 IFA-VIT-positive isolates. The two methods showed very good correlation (96.9%), but RT-PCR-EIA was clearly more efficient in typing, leaving 5% non-A, non-B isolates, while IFA failed to resolve 23% of the isolates. The two methods contradicted each other for <5% of the isolates.


2009 ◽  
Vol 14 (36) ◽  
Author(s):  
M Panning ◽  
M Eickmann ◽  
O Landt ◽  
M Monazahian ◽  
S Ölschläger ◽  
...  

Influenza A(H1N1)v virus was first identified in April 2009. A novel real-time RT-PCR for influenza A(H1N1)v virus was set up ad hoc and validated following industry-standard criteria. The lower limit of detection of the assay was 384 copies of viral RNA per ml of viral transport medium (95% confidence interval: 273-876 RNA copies/ml). Specificity was 100% as assessed on a panel of reference samples including seasonal human influenza A virus H1N1 and H3N2, highly pathogenic avian influenza A virus H5N1 and porcine influenza A virus H1N1, H1N2 and H3N2 samples. The real-time RT-PCR assay for the influenza A matrix gene recommended in 2007 by the World Health Organization was modified to work under the same reaction conditions as the influenza A(H1N1)v virus-specific test. Both assays were equally sensitive. Clinical applicability of both assays was demonstrated by screening of almost 2,000 suspected influenza (H1N1)v specimens, which included samples from the first cases of pandemic H1N1 influenza imported to Germany. Measuring influenza A(H1N1)v virus concentrations in 144 laboratory-confirmed samples yielded a median of 4.6 log RNA copies/ml. The new methodology proved its principle and might assist public health laboratories in the upcoming influenza pandemic.


2012 ◽  
Vol 45 (5) ◽  
pp. 563-566 ◽  
Author(s):  
Sandra Baltazar Guatura ◽  
Aripuana Sakurada Aranha Watanabe ◽  
Clarice Neves Camargo ◽  
Ana Maria Passos ◽  
Sheila Negrini Parmezan ◽  
...  

INTRODUCTION: Influenza A H1N1 2009 is associated with a high morbidity rate among children around the world, including Brazil. This survey was conducted on samples of symptomatic children (< 12 years) to investigate the influenza virus as the etiological agent of respiratory infections in a day care school in a health facility during the first and second pandemic wave of H1N1 (2009-2010) in São Paulo, Brazil. METHODS: Influenza infections were determined by real-time PCR in 34% (47/137) of children with a median age of 5 years (8 months - 12 years), from June to October 2009 and in 16% (14/85) of those with median age of 6 years (1-12 years), from March to November 2010. RESULTS: In general, most positive cases (64%) occurred in children aged 5-12 years, this age group was significantly the most affected (39.8%, p = 0.001, OR = 8.3, CI 95% 1.9-36.9). Wheezing was reported by 31% (19/61) and dyspnea by 23% (14/61) of the studied patients. An outbreak of influenza H1N1 with an attack rate of 35.7% among children (median age 6 years) was documented in April 2010, before the vaccination campaign against the pandemic virus was extended for children up to 5 years in Brazil. CONCLUSIONS: Therefore, the study reinforces the recommendation to immunize school children to reduce the incidence of the disease.


2009 ◽  
Vol 45 (3) ◽  
pp. 203-204 ◽  
Author(s):  
David M. Whiley ◽  
Seweryn Bialasiewicz ◽  
Cheryl Bletchly ◽  
Cassandra E. Faux ◽  
Bruce Harrower ◽  
...  

2016 ◽  
Vol 15 (5) ◽  
pp. 1095-1102
Author(s):  
Yan-di WEI ◽  
Xing-yao PEI ◽  
Yuan ZHANG ◽  
Chen-fang YU ◽  
Hong-lei SUN ◽  
...  

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