Application of Molecular Diagnostic Techniques for Viral Testing

Abstract

Nucleic acid amplification techniques are commonly used currently to diagnose viral diseases and manage patients with this kind of illnesses. These techniques have had a rapid but unconventional route of development during the last 30 years, with the discovery and introduction of several assays in clinical diagnosis. The increase in the number of commercially available methods has facilitated the use of this technology in the majority of laboratories worldwide. This technology has reduced the use of some other techniques such as viral culture based methods and serological assays in the clinical virology laboratory. Moreover, nucleic acid amplification techniques are now the methods of reference and also the most useful assays for the diagnosis in several diseases. The introduction of these techniques and their automation provides new opportunities for the clinical laboratory to affect patient care. The main objectives in performing nucleic acid tests in this field are to provide timely results useful for high-quality patient care at a reasonable cost, because rapid results are associated with improvements in patients care. The use of amplification techniques such as polymerase chain reaction, real-time polymerase chain reaction or nucleic acid sequence-based amplification for virus detection, genotyping and quantification have some advantages like high sensitivity and reproducibility, as well as a broad dynamic range. This review is an up-to-date of the main nucleic acid techniques and their clinical applications, and special challenges and opportunities that these techniques currently provide for the clinical virology laboratory.

Investigational approach to adenoviral conjunctivitis: comparison of three diagnostic tests using a Bayesian latent class model

“…Only then it was reported that the viral culture from the sample was negative for adenovirus [11]. Even though the virus can disseminate and patients remain infectious for about 2 weeks, the virus can be detected by conventional culture usually in the first 7 days and then the detection rate drops down to 25% by day 10, and at 5-10% by day 14 [13].…”

“…All these factors can directly impact the viral recovery rate and thus affect the sensitivity of the viral culture that has been traditionally considered to be the gold standard or reference test [9]. When the reference test is imperfect, the sensitivity and the specificity of an alternative test can be determined by Bayesian LCM statistical analysis which does not assume any test as perfect [13,14]. In this study, the actual sensitivity and specificity of the viral culture, as determined by Bayesian LCM statistical analysis, was 72.2% and 90.8% respectively, although they are traditionally considered to be 100%.…”

Integration of Molecular Methods into Microbiological Diagnostics

“…The use of molecular methods will also reduce the risk of transmission within the community and health care system nosocomial infections [1,4]. Apart from its health complications, nosocomial infections also cause an increase in the cost of intensive care and prolong hospitalization by weeks or more [4].…”

“…The reasons are based on; the timely advantages, detection of slow growing pathogen or nonculturable organisms that are more or less difficult to detect, identify and even to be test for antimicrobial susceptibility by conventional methods [1][2][3][4][5]. This century is conciding with many highly infectious pathogens, notably HIV AIDS that has been dictating our immune response to the emerging of number of infections [2,3,[6][7][8][9][10].…”

Microbiology laboratory and the management of mother-child varicella-zoster virus infection

“…They are more sensitive than viral cultures, DFA and Tzanck smears particularly when primers for genes 28 and 29 are used [30,428,429,440,449,450,457] . Molecular biology tests are also useful in the case of varicella appearing 7-42 d after vaccination, in the case of herpes zoster appearing 42 d after vaccination and, in the case of the suspected transmission of the vaccine virus, can distinguish virus vaccine, wild-type virus and potential recombinants of vaccine and wild-type viruses [30,451,452,454,455,[458][459][460][461][462][463] , although some tests have proved to be less appropriate over time for these purposes [30] . There are also some multiplex assays that can differentiate HSV-1, HSV-2 and VZV in cutaneous and mucocutaneous samples, making them very useful in the case of skin lesions of unclear etiology or immunosuppressed patients [429,464,465] .…”