{"id":2521,"date":"2018-11-13T04:40:03","date_gmt":"2018-11-13T04:40:03","guid":{"rendered":"https:\/\/www.mybiosource.com\/learn\/?p=2521"},"modified":"2023-03-13T12:43:16","modified_gmt":"2023-03-13T12:43:16","slug":"influenza-series-evolution-of-screening-tests","status":"publish","type":"post","link":"https:\/\/www.mybiosource.com\/learn\/influenza-series-evolution-of-screening-tests\/","title":{"rendered":"Influenza Series: Evolution of screening tests"},"content":{"rendered":"\n\n\n
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Table of Contents<\/u><\/strong><\/h3>\n

I. Introduction<\/strong><\/a>
\n\u2022 Overview of Influenza as a Leading Cause of Mortality Globally
\n\u2022 Impact of Influenza on Young Children, Elderly, Pregnant Women, and Those with Underlying Medical Conditions
\n\u2022 Rapid Flu Tests in the U.S.
\n\u2022 Antigen-Based Rapid Flu Tests (RIDTs)
\n\u2022 Nucleic-Acid Based Rapid Molecular Tests
\nII. Diagnosing Influenza<\/strong><\/a>
\n\u2022 Potential Roles of RIDT for Disease Management
\n\u2022 Reclassification of Antigen Detection Test Systems by FDA
\n\u2022 CLIA-Waived Rapid Flu Tests
\n\u2022 Microfluidic Chip to Detect Influenza
\nIII. Nano Microarray-Based Approaches<\/strong><\/a>
\n\u2022 Next-Generation Sequencing (NGS)
\n\u2022 Digital Immunoassays Test (DIA)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Influenza<\/span> is considered one of the leading causes of mortality globally with an estimated 650,000 deaths occurring annually according to the new WHO estimates. It severely affects the high-risk group like the young children, the elderly, pregnant women and those with certain underlying medical conditions such as heart disease, asthma<\/span> and chronic lung disease. Currently, there are 13 rapid flu tests used in the U.S with an acceptable clinical performance of which 6 are antigen<\/span>-based rapid flu tests (also known as rapid influenza<\/span> diagnostic tests (RIDTs) and 7 are nucleic-acid<\/span> based rapid molecular tests available in primary care.<\/p>\n

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Diagnosing influenza As the majority of the influenza<\/span> cases are diagnosed clinically, the challenge of it continues as it could also be indistinguishable from other infections with respiratory syncytial virus, adenovirus<\/span> and others. Therefore, a laboratory test is required to confirm a definitive diagnosis to help with the management of the case and permit monitoring of disease spread which is important for public health. The current diagnostic tests available for influenza<\/span> include serology, viral culture, reverse transcription<\/span> polymerase<\/span> chain reaction (RT-PCR<\/span>), viral culture, rapid molecular assays and immunofluorescence assays. Also, the proper collection and storage of the specimens are important for the detection of the influenza<\/span> infections. The sensitivity and the specificity could vary based on the type of test, the type of specimen used and illness onset to the time the specimen was collected. The preferred samples for influenza<\/span> testing are nasal swab and nasal wash based on the kind of test used and the specimen should be collected within 3-4 days. Except for the RIDT, other forms of diagnosis require sophisticated laboratory capacity equipped with skilled laboratory staff. Rapid influenza<\/span> diagnostic tests (RIDTs) can be used in physician\u2019s offices or clinics without the need for laboratory services and can be interpreted within 5-15 minutes.<\/p>\n

Potential roles of RIDT for disease management<\/strong> Individual patient management:<\/em> Rapid influenza<\/span> diagnostic tests (RIDTs) can assist with the diagnosis and the management of patients presenting influenza<\/span>-like illness (ILI<\/span>). However, the limitations of the commercial RIDTs is that it cannot specifically confirm pandemic influenza<\/span> A (H1N1<\/span>) 2009 virus and a positive results does not differentiate between pandemic (H1N1<\/span>) virus or exclude the infection with seasonal influenza<\/span> A viruses. Therefore, the general use of RIDTs among hospitalized patients should not be encouraged when alternative diagnostics such as RT-PCR<\/span> or Immunofluorescence assay are available. Semi-closed community outbreak management:<\/em> RIDTs can assist in detecting influenza<\/span> A among semi-closed communities and institutions such as schools that report high numbers of ILI which can help with the interventions for institutional control outbreaks. \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <\/strong>Reclassification of antigen detection test systems by FDA<\/strong> As of January 2017, antigen<\/span>-based RIDT systems have been reclassified into class II by FDA to improve the overall rating of testing. This was done mainly because of the poor sensitivity of some of the antigen<\/span>-based RIDTs which has resulted in the number of misdiagnosed cases. By this reclassification, FDA has established controls for antigen<\/span>-based RIDTs so that the accuracy and reliability could be achieved. Accordingly, the manufacturers had time until January 12, 2018 to ensure their tests comply with the new regulation. This is therefore expected to minimize the rate of misdiagnosed infections by promoting the development of improved devices that can identify the influenza<\/span> virus. The Clinical laboratory improvement amendments (CLIA) waived Rapid Flu tests; Available CLIA-Waived, Antigen<\/span>-based rapid flu tests:<\/p>\n