August 5, 2011
A New Species of Tick-Borne Bacteria Identified in Minnesota and Wisconsin
[Lunch warning: Parts of this post are kind of gross. If you’re reading this over a meal, you have been warned.]
What a depressing week. The debt ceiling debate postponed all difficult decisions, second quarter economic growth was revised so low that you need to squint to see it, and yesterday the stock market jumped off the balcony, losing all the gains it’s made over the year.
We need some happy news to distract us from what we used to call our portfolios. How about a new disease spread by tick bites?!!
Ehrlichiosis (er-lick-ee-OH-sis) is a disease characterized by fever, muscle aches and headaches. A third of the cases also have a rash. Severe cases can be fatal, but that amounts to fewer than five deaths per year. It’s treatable with antibiotics. Ehrlichiosis is caused by two species of bacteria, Ehrlichia chaffeensis and E. ewingii which are spread by the bite of the lone star tick. The lone star tick is really ugly, so here’s a picture of it. As you would guess from its name, the lone star tick is found largely in the South, and that’s where cases of ehrlichiosis have usually occurred.
This week’s New England Journal of Medicine published a study which describes a new geography, a new bacterial species, and a new transmitting tick for ehrlichiosis. It describes patients with the typical symptoms of ehrlichiosis in Minnesota and Wisconsin. The bacteria isolated from these patients belongs to the genus Ehrlichia but is a newly discovered species. It is spread by the deer tick, which like the lone star tick is also not a contender for the most beautiful organism.
The deer tick also has the distinction of spreading the bacterium that causes Lyme disease as well as other infectious diseases. Since 2009 there have been 29 identified cases of infection with this new species of Ehrlichia in Minnesota and Wisconsin.
Will this new species spread across the US, giving the deer tick super powers and triggering the inevitable zombie apocalypse? Probably not, but it is likely to spread from its current geography.
The simplest way to manage ehrlichiosis is prevention. Preventing tick bites prevents ehrlichiosis and lots of other tick-borne illnesses. The CDC website has a very handy page about ehrlichiosis with tips for preventing bites and removing attached ticks. When going on hikes remember to wear long pants and to use insect repellant.
So there you go – a pleasant story to distract us from our creeping, blood-sapping, infectious economic woes.
There’s a New Bacterial Species Causing Tick-Borne Illness in Two States (Wall Street Journal health Blog)
Yet Another Reason To Say Ick to Ticks (NPR health blog)
Emergence of a New Pathogenic Ehrlichia Species, Wisconsin and Minnesota, 2009 (New England Journal of Medicine, abstract available without subscription)
Important legal mumbo jumbo: