Epstein-Barr virus and multiple sclerosis: regional mapping does not demonstrate a causal link

Two indicators mapped, not individual follow-up

The researchers compiled 131 studies following a literature search with a cutoff date of June 18, 2022. Their objective was to map, side by side, the prevalence of multiple sclerosis (MS) and the seroprevalence of Epstein-Barr virus (EBV) in countries in the Middle East and North Africa.

For the quantitative analysis of EBV, they selected studies measuring VCA-IgG antibodies in healthy populations. This indicator of exposure to the virus does not constitute an MS diagnosis. The review does not follow the same people from infection through to the possible onset of the disease.

A sharper rise in MS

Across all periods, the pooled prevalence of MS is 51.02 cases per 100,000 people. The pooled seroprevalence of EBV is 75%. These two values describe different indicators: they cannot be used to calculate the risk of MS in someone exposed to the virus.

In studies conducted up to 2000, the pooled prevalence of MS was 12 cases per 100,000 people, compared with 58 in those conducted between 2011 and 2022. Over the same periods, EBV seroprevalence rose from 71% to 75%.

However, this contrast does not measure changes in a single population followed over time. The countries, populations and methods represented may differ between periods.

Averages weakened by widely differing studies

The abstract reports extreme heterogeneity for both indicators. Differences include geography, populations, methods, diagnostic approaches and study periods. The pooled averages should therefore not be treated as estimates that apply uniformly to every country.

The comparison remains ecological: two trends observed at the population level are not enough to establish a relationship at the individual level. Nor can this analysis attribute the rise in MS to increased exposure to EBV.

Prevention remains a hypothesis in this analysis

The authors discuss a potential benefit of EBV prevention for MS, but their review does not test any preventive intervention. This proposal therefore remains a hypothesis, not a clinical finding.

They call for longitudinal population studies with standardized identification of MS and detailed, age-specific EBV serology. This mapping mainly clarifies the questions to explore, without providing individual preventive recommendations.

What we can take away

This review describes two concurrent regional trends. It does not quantify individual risk or demonstrate that preventing EBV prevents multiple sclerosis.