Increased risk of tick-borne illnesses in Minnesota

Posted 6/27/01

Increased risk of tick-borne illnesses in Minnesota

As Minnesotans enjoy the return of warm weather to their state - and begin spending more time outdoors - officials are again reminding people that they need to protect themselves against tick-related illnesses like Lyme Disease.

ìWe had 465 cases of Lyme Disease last year,î said David Neitzel who is part of MDHís Acute Disease Investigations and Control Section. ìThatís a 64 percent increase over the previous record.
ìA number of factors may have contributed to that high number,î he said. ìAmong other things, we had an extended run of nice weather, which probably tended to draw people outdoors. We hope this will serve to remind people that they need to protect themselves when they spend time in tick country.î

Tick country means wooded, brushy areas in 17 east-central and southeastern Minnesota counties - areas that provide habitat for Ixodes scapularis, better known as the ìdeer tick.î About two-thirds of the people who get Lyme Disease in Minnesota are exposed to the illness in those 17 counties. Most of the other cases involve Minnesota residents who were exposed in western Wisconsin.

And itís also important to remember that deer ticks can also carry two other serious illnesses - human granulocytic ehrlichiosis (HGE) and babesiosis - in addition to Lyme disease, Neitzel emphasized. Minnesota had 79 cases of HGE last year - more than double the previous record.

The previous high for both Lyme Disease and HGE occurred in 1999, when the state had 283 cases of Lyme Disease and 36 cases of HGE. Over 3,000 cases of Lyme Disease have been reported in Minnesota since 1982.
Protecting yourself from tick bites is still the first line of defense against these illnesses, according to health officials. Itís also important to be alert for possible symptoms of a tick-related disease if youíve spent time in an area where you could have been exposed, so you can seek prompt medical attention.

Deer ticks are most active between April and September, Neitzel said. However, the most critical time is mid-May to mid-July, when deer ticks in the nymph stage are most active. Eighty percent of Lyme Disease infections are acquired during that period.
Deer ticks are smaller - and darker in color - than the common wood ticks that people encounter this time of year. They also lack the wood tickís characteristic white markings, and the back end of the female deer tick is reddish in appearance.

Areas of the state where youíre most likely to encounter deer ticks include Aitkin, Anoka, Cass, Chisago, Crow Wing, Isanti, Kanabec, Mille Lacs, Morrison and Washington County, the southern portions of Carlton and St. Louis County, the eastern portion of Houston, Wabasha and Winona County, and the northern tip of Ramsey County. Much of the Twin Cities area lies outside this ìhigh-riskî zone.

To protect yourself from tick bites, health officials suggest that you:

ïAvoid possible tick habitat. You wonít place yourself at risk simply by visiting one of the ìhigh-risk counties,î you also have to spend time outdoors, in wooded, brushy areas.

ï Use a good tick repellent - containing no more than 30 percent of the active ingredient DEET - and follow the manufacturerís directions.

ï Wear clothes that will help to shield you from ticks. Long-sleeved shirts and long pants are best. Tuck your pants into the top of your socks or boots, to create a ìtick barrier.î

ï Check frequently for ticks, and promptly remove any that you find, using a pair of tweezers or specially-designed tick forceps. Ticks actually have to bite you - and remain attached for a period of time - before they can transmit disease. Generally, ticks have to remain attached for a day or two to transmit Lyme Disease, although some research suggests that HGE may be transmitted more quickly. Avoid folk remedies like Vaseline, nail polish remover or burning matches - they are not a safe or effective way to remove ticks.

If you do develop a tick-related illness, you should see a physician right away, Neitzel emphasized. Early symptoms of Lyme Disease typically include a characteristic ìbulls-eyeî rash, consisting of a reddened area with a clear area in the middle, at the original site of the tick-bite. The rash may expand in size to cover a very large area, or even appear in several places on other parts of the body.

Not everyone develops the rash, however, so itís also important to be alert for other symptoms of Lyme Disease - fever, headache, chills, and pain in the muscles or joints - if youíve spent time in tick country during the past month.

The symptoms of HGE and babesiosis do not include a rash, but they are otherwise similar to the symptoms of Lyme Disease. Symptoms of HGE can include fever of 102 degrees or more, chills, shaking, severe headache and muscle aches. Babesiosis is characterized by high fever, muscle aches, fatigue and loss of appetite.