Recent advancements in molecular biology techniques promote the rapid identification of infections with greater accuracy than conventional methods. Successfully applied in many areas of DNA testing including molecular diagnosis of infectious disease, multiplex PCR (Polymerase Chain Reaction) is a widespread molecular biology technique for amplification of multiple targets in a single PCR experiment. This assay technique has revolutionized infectious disease diagnosis and proven a valuable method for the identification of viruses, bacteria, fungi, and/or parasites.
Multiplex PCR has the potential to produce considerable savings in time and effort within the laboratory without compromising on the utility of the experiment. Only a limited number of assays have been approved by the US Food and Drug Administration. The FDA recently authorized the use of Real Time RT-PCR (TaqMan®) assay or the EZ1 assay for the suspected Ebola viral infection cases, based on clinical and epidemiological screening criteria.
The real-time PCR assay has many advantages over conventional PCR methods including rapidity, quantitative measurement, lower contamination rate, higher sensitivity, higher specificity, less consumption of reagents and easy standardization. Multiplex PCR tests are ideal for a wide range of clinical applications such as:
- Specific or broad-spectrum pathogen detection
- Detection of HPV infection
- Evaluation of emerging novel infections
- Recognition of mycoplasma fermentans
- Rapid identification of bloodstream infections
- Early detection of bio-threat agents and
- Antimicrobial resistance profiling
Multiplex PCR is also a useful and rapid diagnostic tool for the management of children with acute respiratory infections.
Compared to simple PCR tests, multiplex assays offer many advantages:
- Simplify ordering algorithm
- Increase diagnostic yield
- Can reveal false negatives
- Conserve costly polymerase and templates in short supply
- Standardize testing
However, multiplex PCR pose design issues and not all combinations of tests will work together without affecting test performance. They are also limited by false positive and negative results and the high cost of commercial kits and the need to acquire several types of lab equipment to cover the testing.
Despite these limitations, rapid turnaround time, specificity and higher sensitivity make these tests a powerful tool. As they enable rapid diagnosis, researchers point out that faster diagnosis would lead to savings in healthcare costs due to decreased length of stay and better clinical outcomes for patients.