Detection of rubella virus in biological material by PCR method

The causative agent of rubella is an RNA-containing virus (Rubella virus). Rubella infection is benign and more than half of cases are asymptomatic. However, if a woman is infected during pregnancy, especially during the first 16 weeks, it can lead to serious consequences, causing fetus death or congenital malformations known as congenital rubella syndrome (CRS). Timely diagnosis in this situation is especially important and determines the subsequent tactics of pregnancy management.

The source and reservoir of infection is a person in the period of 1 week before the appearance of rashes and 5-7 days after. The highest concentration of the virus in the blood reaches approximately 10-14 days after infection and before the appearance of clinical signs. During this period, the patient's infection with the rubella virus can be determined exclusively by direct diagnostic methods, since this stage is a period of the "serological window", during which the fact of infection cannot be confirmed by serological diagnostic methods. After the rash appears, the virus can be detected in the blood for another 7 days. Subsequently, the virus is eliminated from the blood and is detected already in oropharyngeal smears up to 2 weeks after the rash appears. In the case of congenital rubella in children, the virus can be excreted from the body during the first 1-2 years after birth.

A promising area of laboratory diagnostics for the detection of rubella virus is the PCR method. Compared to serologic and virologic approaches to rubella diagnosis, PCR has the following advantages:

• direct detection of the presence of the pathogen;
• high sensitivity, which allows diagnosing acute, asymptomatic and slowly progressive forms of the disease, as well as examining contact persons at times when serologic methods are not yet effective (“serologic window”);
• high specificity, which allows detecting a unique, characteristic only for the pathogen genomic region of nucleic acid in the studied material, which eliminates the possibility of false results.

In the OLYMP CDL branches, PCR analysis are done in REAL-TIME mode, which means that after each hardware cycle (amplification), the amount of DNA in the biomaterial is measured. This procedure reduces the probability of a false positive result to almost zero! The test material is blood or scraping from the throat.