Fittingly for Halloween, I tripped across these articles on PubMed today. Apparently Wizarding/Muggle medical relations are an issue. Just in case you want to brush up on this important subject, I've provided links to the articles, both from respected Muggle medical journals.
Lim EC, et al. Duty of care to the undiagnosed patient: ethical imperative, or just a load of Hogwarts? CMAJ. 2006 Dec 5;175(12):1557-9 (PMID 17146093)
Lim EC, et al. Interesting in- and outpatient attendances at Hogwarts Infirmary and St Mungo's Hospital for magical maladies. Ann Acad Med Singapore. 2006 Feb;35(2):127-9. (PMID 16565770)
If I find any more, I will certainly keep you updated. I think we all need to be aware!