EBV & Bradford-Hill

Re: Curious Orange’s post on “An EBV controversy“:

“Hello, in a previous thread you mentioned that in adult MS, EBV is found in 99.9% of cases. This struck me as an amazing statistic, then I googled a bit and read that over 95% of the general population also show evidence of EBV infection. Now it seems a bit less amazing…

Can anyone out there help me understand why this small difference is so significant? Also, how well does the EBV theory fit into Bradford-Hill’s 9 criteria for causation? Thanks”

“I agree that at first glance this seems less amazing; however the negative predictive value is very high. In other words if you don’t have EBV you are virtually protected from getting MS; your risk is close to zero! This is one of the strongest arguments that I keep putting forward when making the claim that  EBV is the cause of MS.”

“Regarding Bradford-Hill criteria. I recently gave a talk at the MS Frontiers meeting at Heathrow Airport and concluded my talk with the following slide.”

“EBV ticks between 2 and 6 of Bradford-Hill criteria; it depends on how strong the evidence is and if you are willing to accept the evidence.” 

“There is debate on the strength of the EBV-MS association; with a relative risk of between 2 and 3. A low relative risk of developing MS due to EBV is to be expected as it would be a rare manifestation of a common exposure. High relative risks are only found with common manifestations of uncommon or rare exposures.”  

“What is essential for causation is experimental evidence. If we prevent (vaccination) or suppress EBV  (anti-viral drugs) to we prevent or cure people of MS? These are strategies high-up on our research agenda.”

“In isolation the conclusion slide is difficult to understand. I will therefore make a video and post it on YouTube to explain it in more detail.”

Other posts of interest:

01 Jun 2011
I am giving a debate at the MS Frontiers meeting taking place 23-24 June 2011 at Sofitel , Heathrow. The following is my abstract. “Multiple Sclerosis is caused by Epstein Barr virus” 

5 thoughts on “EBV & Bradford-Hill”

  1. I got chicken pox as an adult (17 years old) and then developed MS within 10 years of that. Are the two situations linked? Aren't both pox and EBV forms of herpes?

  2. Re: "Aren't both pox and EBV forms of herpes?"Yes, they are both members of the herpes virus family. However, there is no evidence that I am aware of the varicella zoster virus, the virus that causes chicken pox is linked to MS.

  3. Re: "Re Varicella & MS"This study probably is a non-specific observation, i.e. viral infections are a trigger of relapses. A meta-analysis VZV studies does not show any consistent association: 1. Haire et al, RR = 0.66 (0.19–2.12. Bray et al, RR = 0.77 (0.53–1.1) 3. Myhr et al, RR = 1.2 (0.16–9.0) 4. Sundstrom et al, = 1.4 (0.54–3.2If you are interested this reviewed in the following paper: Ascherio and Munger. Environmental risk factors for multiple sclerosis. Part I: the role of infection. Ann Neurol. 2007 Apr;61(4):288-99.

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