The positivity rate of Epstein-Barr virus anti-viral capsid antigen IgG among children with infectious mononucleosis in Diyala-Iraq

Background: Epstein-Barr virus (EBV) is a double-stranded linear DNA human herpesvirus that is transmitted primarily through saliva during childhood. Although the majority of primary EBV infections are clinically asymptomatic, clinical cases are presented as infectious mononucleosis (IMN) syndrome.

Objectives: This study was conducted to explore the rate of EBV anti-VCA IgG among children who were clinically suspected as having IMN in Diyala province.

Subjects and methods: This is a cross sectional study that was carried out during 2018 in Diyala province- Iraq. A total of 370 blood samples were collected from 190 children under 15 years of age who were clinically suspected as having IMN, and 180 apparently healthy children as controls. The anti EBV VCA IgG antibodies were detected in serum using the VCA IgG ELISA kit (from Dia.Pro Diagnostic Bioprobes srl - Italy). Statistical analysis was carried out using the SPSS- version 25. A statistical significance was considered whenever the P value was ≤ 0.05.

Results: The results showed that the IgG positivity rate among suspected IMN patients was insignificantly higher in the age group 10-14 years old children (80.8%, P = 0.364). In control subjects the highest positivity rate was in the age group of 1-4 years with a statistically significant difference (79.5%, P = 0.002). In suspected IMN patients, the age group of 10-14 years had the highest mean concentration ± SD of anti-VCA IgG (44.018 ± 38.644 arbitrary units per milliliter (arbU/ml)), while in controls, the highest value (38.018 ± 34.908 arbU/ml) was in the age group of 1-4 years, with insignificant difference in either group (P = 0.257 and 0.072, respectively). The results also showed that in both suspected IMN patients and control subjects, females showed higher IgG positivity rate (70.6%, and 75.5%) compared to males (64.8%, and 65.1%) with insignificant difference in both groups (P = 0.392 and 0.126, respectively). Similarly, the IgG mean concentration ± SD was insignificantly higher in females in both suspected IMN patients and control subjects (P = 0.447 and 0.256, respectively). 21 (87.5%) IgM positive suspected IMN patients were also IgG positive with a statistically significant association (P = 0.028).

Conclusion: The positivity rate of anti-EBV VCA IgG among apparently healthy subjects in Diyala province was 70.6%, and the rate increases with age, with slight association with clinical suspicion of infectious mononucleosis.