Comparison of serological and molecular test for diagnosis of infectious mononucleosis

Epstein-Bar virus (EBV) is the main etiology of infectious mononucleosis (IM) syndrome that is characterized by fever, sore throat, and lymph adenopathy. Since, this virus could be associated with a number of malignancies, some hematologic disorders, and chronic fatigue syndrome, identification of IM is very important. The aim of study was to evaluate the specificity, as well as sensitivity of the two different methods that is, serology versus molecular diagnosis that are currently used for diagnosis of IM.

In this study, during a period of 3.5 years, 100 suspected patients as case group and 100 healthy individuals as a control group were studied. Fifty samples in each group were tested by polymerase chain reaction (PCR) and all the samples including case group and control group were carried out by enzyme-linked immunosorbent assay (ELISA).

In 76% of patients and in 20% of the healthy individuals, samples were detected EBV DNA by PCR. On the other hand, 68.5% of the samples belong to the case group and 46% in the control group showed positivity by ELISA.

By comparing the two methods, since PCR is very expensive and time consuming, and the percentages of difference ranges are narrow, ELISA could be applied as a first, easiest, and preliminary diagnostic test for IM. In addition, this test could be applied in various phases of the disease with a higher sensitivity comparing to PCR. Although PCR is routinely used for diagnosis of various infectious agents, it is considered as an expensive test and merely could be used after 1-2 weeks from the onset of the illness.