Application of Molecular Diagnostic Techniques for Viral Testing

Cobo, Fernando

Molecular diagnostic techniques for viral testing have experimented a rapid development during the last years [1] , and have been introduced in the majority of laboratories as a new way for the diagnosis of human pathogens like viruses. This field of molecular microbiology presents many challenges to the practice of laboratory medicine, above all the implementation like automated methodology. The introduction of fully automated devices with faster turnaround times has allowed clinical laboratories the necessary tools to report sensitive and accurate results to physicians. The goals in performing microbiology nucleic acid tests (NAT) are mainly to provide timely results useful for high-quality patient care at a reasonable cost. Rapid results obtained by NAT are associated with improvements in patient care. Empiric data and modeling studies find that faster detection of enteroviral meningitis using NAT is associated with reduced length of stay and duration of antibiotic administration, as well as substantial cost savings [2] . The use of amplification techniques such as polymerase chain reaction (PCR), real-time PCR or nucleic acid sequence-based amplification (NASBA) [3] for virus detection, genotyping and quantification have some advantages like high sensitivity and reproducibility, as well as a broad dynamic range [4, 5] . A great number of qualitative and quantitative molecular virus assays, mostly *Address correspondence to this author at the Microbiology Unit (Biotechnology Area), Hospital de Poniente. Ctra de Almerimar S/N, El Ejido 04700, Almería, Spain; Tel: [phone]; E-mail: [e-mail] based on PCR technology have been described [6, 7] . NASBA assays could identify active infection by detecting viral messenger RNA (mRNA) but the most widely used tests in clinical virus diagnosis are quantitative real-time PCR techniques [8] . Many molecular diagnostic methods have been replaced by automated devices that use less time, manipulate smaller volumes of liquids and provide quantified results with better precision. Molecular techniques have revolutionated the diagnosis of infectious diseases, particularly the diagnosis of viral diseases. Automation of these methods provides decrease in turnaround times, low contamination risk, ease of performance and speed, as well as the ability to have lower detection limits and to diminish cost per test. This review focuses on the application of molecular technology in the clinical virology laboratory. Table 1 summarizes the main molecular techniques used in clinical virology.