Research: viral infection and evidence is with EBV

Zaadstra et al.  Selective association of multiple sclerosis with infectious mononucleosis. Mult Scler. 2008;14(3):307-13.

Previous studies have suggested an association between MS and infectious mononucleosis (IM) but data on the exact strength of this association or its selectivity have been conflicting. In this study the investigators evaluated the association between MS and a variety of common childhood infections and afflictions in a large population-based case-control study involving 2,877 MS cases and 2,673 controls in the Netherlands.

They examined the frequency of different common infections and afflictions before the age of 25 and the age at which they occurred, using a self-administered questionnaire. The Odds ratios (ORs) for the occurrence of a variety of clinically manifest common childhood infections including rubella, measles, chicken pox and mumps before the age of 25 for MSers versus controls ranged between 1.14 and 1.42, values similar to those for irrelevant probe variables used to reveal recall bias.

In contrast, the OR for clinically manifest IM in MS cases versus controls, corrected for demographic variables, was 2.22 (95% confidence interval 1.73 - 2.86; P < 0.001). The average age of onset of IM in the population of MSers (16.5 years) did not differ from controls (16.8 years). Their data confirm previous much smaller studies to show that the risk for MS is significantly enhanced by prior IM, and extend those previous data by showing that this association is far stronger than with other common childhood infections or afflictions.

Ramagopalan et al.  Association of infectious mononucleosis with multiple sclerosis. A population-based study. Neuroepidemiology. 2009;32:257-62.

BACKGROUND: Genetic and environmental factors have important roles in MS susceptibility. Several studies have attempted to correlate exposure to viral illness with the subsequent development of MS. Here in a population-based Canadian cohort, the researchers investigated the relationship between prior clinical infection or vaccination and the risk of MS.

METHODS: Using the longitudinal Canadian database, 14,362 MS index cases and 7,671 spouse controls were asked about history of measles, mumps, rubella, varicella (Chicken pox) and infectious mononucleosis as well as details about vaccination with measles, mumps, rubella, hepatitis B and influenza vaccines. Comparisons were made between cases and spouse controls.

RESULTS: Spouse controls and stratification by sex appear to correct for ascertainment bias because with a single exception we found no significant differences between cases and controls for all viral exposures and vaccinations. However, 699 cases and 165 controls reported a history of infectious mononucleosis (p < 0.001, corrected odds ratio 2.06, 95% confidence interval 1.71-2.48). Females were more aware of disease history than males (p < 0.001).

CONCLUSIONS: The data further confirms a reporting distortion between males and females. Historically reported measles, mumps, rubella (German Measles), varicella (Chicken pox) and vaccination for hepatitis B, influenza, measles, mumps and rubella are not associated with increased risk of MS later in life. A clinical history of infectious mononucleosis is conspicuously associated with increased MS susceptibility. These findings support studies implicating Epstein-Barr virus in MS disease susceptibility, but a co-association between MS susceptibility and clinically apparent infectious mononucleosis cannot be excluded.

"There have been many studies reporting the link between certain viruses and MS. But when looked at using larger sample sizes most viruses have fallen by the wayside. The exception appears to be Epstein Barr Virus (EBV) which causes glandular fever or infectious mononucleosis If you have glandular fever and got the virus in adolescence it increases your risk (using the data above about twice as likely) of developing MS. Search on the BLOG for EBV and infectious mononucleosis and there are loads of posts as a pet subject of Prof G."

CoI: Studies were my members of Team G or from the partners of people from Team G