LABORATORY COMPARATIVE ANALYSIS OF SEROLOGICAL AND MOLECULAR BIOLOGICAL METHODS FOR DETECTION OF MEASLES VIRUS IN BULGARIA

Abstract

This study aimed to perform a comparative analysis between the frequency of detection of the measles virus in Bulgarian patients by using two types of laboratory methods - serological and molecular. Materials and Methods: The total 202 patients with two types of clinical material (serum samples and nasal swabs) were tested. The specimens were collected during the measles outbreak in Bulgaria in 2019. The serological - indirect EIA test for detection of specific IgM antibodies and molecular methods - extraction and detection of viral RNA were used. Results: In the present study, tested Bulgarian patients were divided into 11 age groups. The majority of patients were under 9 years of age (126/202, 62%), including children under 1 years of age (31/202, 15%).  Acute measles infection was confirmed by ELISA-IgM in 136/202(67%) and by RT-PCR in 138/202 (68%) of cases. The positive patients detected only by PCR methods are mainly in younger tested. In 123/202 of the patients (60,89%) measles infection was confirmed by a combined serological and molecular-biological approach. The coincidence percentage rate of results obtained is 87%, including double positive (n=123) and double negative (n=52) tests. No significant differences in the results in terms of gender and age were found. Conclusion: The combined  laboratory approach (immunoenzymatic and molecular assay of each  suspected case) is a requisite for measles detection, especially before the onset of symptoms when specific Ig M antibodies could not be detected. Molecular biological techniques are basic and preferred approach in the field of modern biomedical sciences.  They play an important role in the early and accurate etiological diagnosis and monitoring of viral infections, in particular the measles virus.