To examine a patient with an infection, specialized laboratory diagnostics are often required, which can also be done with point-of-care tests. However, many analytical and preanalytical factors that affect the reliability of the POC tests should be considered. It should also be noted that clinical microbiology testing is subject to a permit in our country. These and many other issues related to the treatment path of an infectious patient were discussed at the National Near Patient Testing Days organized by Labquality on 3.11.2022.
During the pandemics, it was speculated that the permit for clinical microbiology testing was unnoticed by many, who offered these tests without authorization. The purpose of authorization is to improve the quality of microbiological diagnostics by making sure that the personnel is aware of the analytical and preanalytical factors, which affect quality of POC testing. Therefore, reliability of the unauthorized testing may not be as good as in the authorized laboratories. Although, the diagnostic devices used are CE-marked for their intended use, sampling requires professionalism. This is especially true for POC tests in molecular biology, which are carried out using a technique in which the user simply adds a sample to the device. It is not clear to many that, for example, a high-quality sample does not contain a mucus or other material that does not belong to it, which prevents the correct processing of the sample in the analytical device.
There is an increasing number of direct detection methods on the markets based on the detection of RNA or DNA of pathogens by thermal or isothermal reaction mechanisms. Traditional RT-PCR techniques are very sensitive and specific, although newer isothermal RT-PCR methods are easier to automate than traditional methods and are therefore more suitable for point-of-care testing. Due to the complexity of the reaction, isothermal reactions are slightly more non-specific than traditional thermal reactions, and therefore they are often also particularly device specific. Isothermal reactions are subject of very intensive research and development, and we therefore have reason to believe that in the future they will also be more usable and accurate. Direct detection methods should be preferred over indirect methods if one is available. Direct detection methods are more sensitive and specific, although they are often slower and more expensive. Rapid tests can sometimes be difficult to interpret by eye and in this case. However, optical readers can add reliability of such tests.
Up to 90% of the infections found in the doctor’s office are harmless and do not require immediate medical treatment. It is known that rapid diagnostics speeds up the treatment chain especially in cases where there is a reason to suspect a serious infection that can be treated with antibiotics. Surprisingly, many patients are keen to see numerical value, which may or may not support one’s diagnostics. CRP result is widely used to support the assessment of the need for antibiotic treatment, and point-of-care testing of CRP can significantly speed up this decision.
The day was very rewarding and brought together a large group of professionals interested in this theme, and I believe that we will meet again around this theme in February 2023 at the Labquality days.