Health Care
6:12 pm
Fri January 18, 2013

New tick-borne disease discovered in New England

The bacteria is called Borrelia miyamotoi, and, like Lyme disease, it hitches a ride in ticks. I'll have more on this in the coming days, but here's a heads up on some of the more unique features of this bug.

Tick larvae in a vial.
Credit Photo by: KRISTIN GOURLAY

This bacteria can cause something like the flu, or a fever that just keeps coming back. You might have had it and not known it, or had it along side Lyme. Common antibiotics can cure it. But if your immune system is already weak, it could lead to some neurological damage.

Scientists first identified B. miyamotoi in Japan. It's been spreading West, slowly. But a couple of years ago, Yale researchers discovered it in deer ticks in New England. They predicted it would start showing up in people, and sure enough, they were right. In 2011, the first human cases popped up in Central Russia. Lately, a few have been identified in the U.S.

It's significant that researchers spotted it in the ticks first, because that's not usually how the disease discovery story goes. More often, we notice a disease in people first and then try to figure out what's causing it.

It's significant that researchers spotted it in the ticks first, because that's not usually how the disease discovery story goes. More often, we notice a disease in people first and then try to figure out what's causing it.

The scientists who've just published the results of their study in the New England Journal of Medicine, that examined blood samples from hundreds of New Englanders, are the very same I worked with on a series of stories about tick-borne illness on Block Island. Peter Krause and Durland Fish are epidemiology and public health researchers at Yale. They studied blood samples from hundreds of New Englanders and found the prevalence of infection with this new bacteria small but significant. About 1% of health people had it. About 3% of people who already had Lyme were carrying it. Krause estimates that for every seven cases of Lyme in the Northeast, there's probably one case of infection by B. miyamotoi.

Here's something else unique about this bacteria: Krause tells me it can change "coats." So when B. miyamotoi infects a human, the human immune system attacks it. The bacteria's numbers dwindle, the infection subsides. But this bacteria is a master of disguise. It changes coats (or protein covers), and at first the body doesn't recognize it. The bacteria multiplies again and the fever comes back. This can happen at least 10 times, according to Krause.

So, should you worry? I'd say don't panic, but definitely protect yourself against deer tick bites when the season starts up again. They carry more than Lyme and this new bacteria. They carry babesiosis and other nasty illnesses you also want to avoid.