Multiplex Real-Time PCR multi-agent technique in the diagnosis of respiratory infections in children

The article was written by Resident Doctor, Doctor Nguyen Thi Thuy Hang - Doctor of Microbiology, Laboratory Department - Vinmec Times City International Hospital.

Respiratory infections are a common problem during the first years of a child's life. It is estimated that a healthy child under 3 years of age can have 3-10 respiratory infections in a year.

For bacterial pathogens, most can be cultured easily such as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus... However, some pathogens require separate culture media and conditions such as Mycoplasma pneumoniae, Bordetella pertussis... Furthermore, the incubation period can be extended up to 7-10 days.

For viral etiologies, the identification of viral infections by traditional methods - viral culture, direct immunofluorescence and rapid antigen testing - is in many cases too laborious or not worthwhile. As reliable as direct immunofluorescence and rapid antigen tests provide results within hours, but in many cases they lack sensitivity and specificity and are only available for certain viruses. Serological tests are not suitable for the diagnostic evaluation of acute respiratory tract infections.

Real-time PCR method has high sensitivity and specificity, up to over 95%, shortening the time to return results compared to traditional culture methods from 72-120 hours to 24 hours, helping to diagnose It is easier to diagnose the cause of the infection.
Furthermore, the multi-agent Real-time PCR method allows simultaneous testing of many pathogens in a single analysis and is therefore becoming more and more important, because of the required specimen volume, time and cost. The cost is almost the same as that of single-agent PCR, which saves doctors the number of orders, reduces the time waiting for results due to the lack of clinical symptoms to identify the cause of infection.

Vinmec Times City International General Hospital has applied Real-time PCR multi-agent technique in diagnosing the root cause of respiratory infections, including individual panels for bacteria and viruses (each panel is about 7 agent).
In particular, the hospital now has an automatic Real-time PCR system (FilmArray system), shortening the time to return results to 2 hours with a composite panel for 34 respiratory pathogens including including bacteria, viruses, yeasts and some specific resistance genes.
These results are very useful, helping doctors to avoid using the wrong antibiotics, especially avoiding the use of antibiotics in which bacteria carry resistance genes.
However, each method has its own disadvantages. PCR can detect many causes, shorten the time to return results, but can not get antibiogram results. Therefore, to achieve the most effective diagnosis and treatment, the physician should consider the appropriate combination of culture tests and PCR.