An ongoing dialogue on HIV/AIDS, infectious diseases,
August 26th, 2010
Lyme Cases Up — Anecdotes, True Epidemiology, and More Anecdotes
All of us New England-based ID doctors (and internists and family practitioners and pediatricians and NPs/PAs in primary care) who have been in practice a while will tell you that Lyme cases have been increasing for years.
And it’s not just the number of cases, it’s also where and when they are occurring. A few years ago I saw acute Lyme in a man who had hiked near his country house in the Berkshire mountains — in early December. (Yes, it was a warm spell.)
One other memorable case was a woman whose only outdoor exposure was a brief walk through the Fenway Victory Gardens, which are located not 100 yards from Fenway Park — an area hardly known as a hotbed of tick-borne infections.
The funny thing is that the local Brookline Society of Amateur Epidemiologists* has noted that this year Lyme cases seem to be down somewhat, at least compared to the last few seasons. (*My wife and me.) Hence this front page article in the Boston Globe initially took us by surprise.
But the explanation for this apparent contraindication is in the rest of the article, which comments not on this year’s case numbers, but on the trend over the past 10 years — which is exactly what all of us have noted as well.
Lyme disease, the tick-borne ailment once primarily a scourge of the Cape and Islands, is now rampant in swaths of Massachusetts where locally acquired cases were rare a decade ago.
And what about our sense that cases are actually down this year compared to last?
Could be just anecdote — that’s what real epidemiologists are for, to see if this impression is real.