As a personal history account, my "relapse" that triggered my diagnosis followed two months after the disovery of a bad periodontal abcess requiring antibiotics (and a root canal), gut problems from the antibiotics and weight loss (besides, I couldn't chew) and loads of personal stress. Based on the MRI (and personal reflection) I've probably had MS for at least 20 years but never had enough neuro symptoms to get a neuro referral. In my childhood and teens, I had so many various GI and respiratory illnesses that I can't pinpoint anything in particular. I don't personally know anyone with MS, and have no family history of it, although there are some other "autoimmune" diseases in my family.
The thing that bothers me about MS is at least the RRMS behaves a lot like some of the diseases of inborn errors of metabolism that appear to be aggravated by conditions that cause metabolic stress, and one of those stressors is an infection; another stressor is prolonged fasting and poor nutrition. I had both going on immediately prior to my diagnosis.
For a metabolic disease example, partial biotinidase deficiency can show up in child that appeared healthy but got subjected to the stress of an infection. Here's a link to a summary of biotinidase deficiency:
if interested, go to the section under "Lab Workup", although there is discussion throughout the document. The symptoms are grim, but the upside is it is treatable with biotin.
The same pattern of stress aggravation is true for Hartnup disease, which involves tryptophan absorption. People who get adequate protein are rarely symptomatic, but an illness can trigger all sorts of problems.
For any real gluttons for punishment out there, a grueling discussion of all sorts of progressive versus intermittent or episodic types of ataxia is here:
I put these out there, not to suggest that MS is really one of these other diseases (although for some people that could be possible) but to indicate there is a pattern of exacerbation of the neurological symptoms associated with these diseases, and they have an identified genetic error of metabolism. It might appear that infection could "cause" the disease in these people, but an infection, through causing metabolic stress, only unmasked a problem that was already there. I think it is a possibility that MS might be the same, only we probably have more than one enzyme that is not optimal, or the inheritance patterns would be clearer, and it may take a combination. And the enzymes can't be too dysfunctional, or we wouldn't have made it to adulthood.
I think it is notable that the recommended workup for these other diseases is an investigation into metabolic markers to help make the diagnosis, but it seems like since I got an MS diagnosis there is nothing else to look at and all symptoms I have are just chalked up to MS. If, while we are in a relapse, we got the blood and urinalysis recommended for some of these other conditions, what might show up? What patterns might be seen among MS patients?
Just some ideas on a different way of looking at infections,