Lyme Disease

In recent years, the health department has seen an increased number of physicians testing for Lyme disease.  The health department follows up on individuals whose test results indicate they may have the disease.  The follow up is completed to obtain more information about the symptoms experienced and travel history.  This is completed to assist the Wisconsin Dept of Health and CDC to assess the demographic, geographic and seasonal distribution of Lyme disease to target prevention and contoll measures.   

Confirmed or Probable Cases


 Cases in WI

Winnebago County   















Lyme disease can be transmitted to humans through the bite of a black legged tick called Ixodus Scapularis (also referred to as the deer or bear tick).  The tick is very small and can be easily overlooked, especially when in its nymph stage.  At this stage, it is less than one millimeter in size and can appear to look just like a speck of dirt on the skin.  See the photo showing the tick at its larva, nymph, and adult male and adult female stage.  In the nymph stage and the adult female stage, they can transmit the bacteria causing Lyme disease. 

Life Stages of Deer Tick 

Signs & Symptoms 

Lyme is most often first identified by the erythma migrans rash.  It will start as a bright red raised circular area that expands to 5 cm or larger with a center clearing (see photo for examples).  This rash is often accompanied with flu-like symptoms--headache, low grade fever, and body or muscle aches.  These symptoms may not show up for days or weeks after the tick bite and not everyone will experience the rash.  If left untreated, Lyme disease can cause serious long term health problems including arthritis, cardiac problems, and neurological problems.    When caught early it is easily treated with antibiotics.

Rash that can be associated with tick bite 


Prevention is the key to avoiding Lyme disease.  Start with avoiding wooded brushy or grassy areas and covering any exposed skin with clothing.  Unexposed skin and clothing can be protected by the use of a repellant. An effective ingredient is Deet with concentrations of 20-30% for adults and for children.  Even when these measures are taken, a tick check is another very important step in Lyme disease prevention.   A deer tick must be present for 24-48 hours before it can transmit the bacteria.  Check for ticks closely and thoroughly, pay attention to the appearance of specks of dirt, this could be a tick in its nymph stage.  If it does not wipe away easily look more closely.  To remove a tick, always use a tweezers, grab the tick as close to the entry point of the skin as possible and gently pull straight out without squeezing the body.   After removing the tick wash the area well with soap and water.  If it has been less than 24 hours you may have avoided the transmission of the bacteria.  If it may have been longer, watch for signs and symptoms and see your physician if noted.



Wisconsin is endemic meaning that Wisconsin does have tick populations with the bacteria that causes Lyme disease.  The highest concentrations have been noted in counties along the Wisconsin River and to the west; however, it has been noted in most areas of Wisconsin.   Many of the cases the health department has followed have been in Winnebago County residents that have traveled to other areas of the state or country.  Infected tick populations have been identified in many of the Upper Mid West states including Minnesota, Upper Michigan, Iowa, Illinois and Indiana.  Another heavy area of concentration is along the east coast from Maine to Massachusetts.   Peak feeding time is May through July.


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