Diagnosis of viral infection using real-time polymerase chain reaction

Abstract

The laboratory-based diagnosis of viral infection has been evolving over the years, to increase objectivity, accuracy, and sensitivity via the continuous development of various technologies. Cell culture, which is one of the methods used for the diagnosis of viral infection, is a "gold-standard" approach; however, it is time consuming and is associated with a high risk of contamination. To overcome these shortcomings, molecular biology methods, such as conventional polymerase chain reaction (cPCR), real-time PCR, and sequencing, have been used recently for virus diagnosis. Realtime PCR has higher accuracy and sensitivity compared with cPCR. Moreover, realtime PCR can quantify viral nucleic acids by confirming the amplification using the threshold cycle, which is the initial amplification point. Real-time PCR applications for the detection of various types of viruses in clinical settings should be based on the use of appropriate samples, nucleic acid extraction according to virus characteristics, and selection of diagnostic methods using sensitivity and specificity targets. In addition, the implementation of real-time PCR requires to evaluate the performance of the test protocol by measuring sensitivity, specificity, accuracy, and reproducibility. The verified real-time PCR method is an easy, fast, and accurate method for monitoring the diagnosis and treatment outcomes in a clinical setting. In this review, we summarize the characteristics of the typical diagnostic methods for viral infection, especially of the advanced real-time PCR method, to detect human pathogenic viruses.