Introduction: Early detection of emerging influenza virus variant is a key factor in the WHO influenza Global strategies for prevention and control. Rapid, accurate, inexpensive and portable detection systems are needed for influenza virus diagnosis and surveillance. Such a detection system should easily identify all the subtypes of influenza virus. Degenerate primers and probes designed from evolutionally conserved regions for known influenza A viruses present the best way to identify unknown subtypes of influenza A virus by polymerase chain reaction PCR and array techniques. The isothermal reactions, Nucleic Acid Sequencing Based Amplification (NASBA) and Loop-mediated isothermal Amplification (LAMP) possess great potential for influenza A virus detection especially in developing countries. However, multiplex real-time (rT) or quantitative (q) polymerase chain reaction (qPCR) remains a rapid, accurate and timesaving technique used for influenza virus detection. Aim: This manuscript explained the principles of nucleic acid amplification techniques commonly used in developing countries. Methods: Literature search was done in NCBI PUBMED, PUBMED Central and Google Scholar using words and phrases including “Influenzamolecular diagnosis, NAAT”, Molecular techniques/ methods, PCR, qPCR, NASBA, LAMP, and DNA microarray. Results: The underlining principles and basic processes involved in the application of nucleic acid amplification techniques for the detection and epidemiological surveillance of influenza virus were identified and grouped under PCR (RT-PCR and qRT-PCR) and Non-PCR (LCR, pyrosequencing, NASBA, LAMP and DNA microarray) amplifications. Conclusion: It is hoped that by understanding the techniques and basic principles of Nucleic acid amplifications, less expensive, and more convenient protocols for influenza virus detection and surveillance can be developed Keywords: Influenza, NAAT, Molecular, PCR, qPCR, Viral diagnosis.
Two Cases of Severe Bronchopneumonia due to Influenza A (H3N2) Virus. Detection of Influenza Virus Gene Using Reverse Transcription Polymerase Chain Reaction.