The COVID-19 pandemic has shone the light across a wide spectrum of medical advances such as the benefits of PCR molecular testing for infectious diseases.
“The PCR test has been the gold standard test for diagnosing COVID-19 since authorized for use in February 2020. It’s accurate and reliable,” says the Cleveland Clinic, ranked as one of the top hospitals in the United States.
It should come as no surprise that PCR molecular testing is considered the gold standard today. Because of advances in the technology in the past 20 years some are comparing it to the breakthroughs from two centuries ago of Louis Pasteur, considered the “father of microbiology.”
“Molecular PCR testing is the 21st century’s answer to what Louis Pasteur created 200 years ago,” wrote Dr. Estee Davis and Rami Packard in the Orlando Medical News in December 2019, on the eve of the coronavirus pandemic.
Unlike traditional culture testing, which can take on average 3 to 5 days and sometimes up to 20 days for fungal infections, PCR molecular testing from collection to pathogen detection to treatment selection can sometimes all be accomplished within 24 hours.
“The diagnosis of infectious diseases has been revolutionized by the development of molecular techniques, mainly with the application of polymerase chain reaction (PCR),” says the Synthetic Biology textbook. “The high sensitivity, specificity, and ease with which the PRCR can be used to detect genetic sequences known have led to their wide application in science.”
The Cleveland Clinic describes molecular PCR testing as “a test to detect genetic material from a specific organism, such as a virus. The test detects the presence of a virus if you have the virus at the time of the test. The test could also detect fragments of the virus even after you are no longer infected.”
The National Library of Medicine’s MedlinePlus describes PCR tests as a fast, highly accurate way to diagnose certain infectious diseases and genetic changes.
PCR molecular tests work by finding DNA or RNA of a disease-causing organism (pathogen) or abnormal cells in a sample.
Most viruses and other pathogens contain either:
“During a PCR test, a small amount of genetic material in a sample is copied multiple times. The copying process is known as amplification. If there are pathogens in the sample, amplification will make them much easier to see,” says MedlinePlus.
PCR tests, which including standard PCR testing as well as rtPRC (reverse transcription PCR) and qPCR (quantitative PCR) and real-time PCR, are used to:
MedLinePlus explains molecular PCR testing in the following steps:
Your PCR test may be taken by either blood test, with a healthcare professional using a small needle to draw blood from a vein in your arm, or via a nasal swab, either from the front part of your nostrils (anterior nares) or from the back of your nostrils (nasal mid-turbinate).
“PCR tests are an accurate and reliable method for identifying many infectious diseases. And because they are often able to make diagnoses before symptoms of infection occur, PCR tests play a crucial role in preventing the spread of diseases,” concludes MedlinePlus.
Davis and Packard in their article argue that doctors rarely receive accurate timely answers with traditional testing.
“Traditional approaches to identify the pathogens responsible for enteric infections can be time consuming and lack sensitivity, which can lead to misdiagnosis. They face a large burden from a variety of respiratory tract infections which can be very expensive and difficult to diagnose,” write Davis and Packard.
The key benefits to molecular PCR testing include: