July 1, 2013

It’s Summer – a “Hot” Time for Lyme Disease

By Julie Suchanek, MBA, MT (ASCP)
Metropolitan Medical Laboratory, PLC

As you enjoy being outdoors this summer, it may surprise you to know that the blacklegged (deer) tick is well established in Iowa and Illinois. Infected ticks can transmit Lyme disease, as well as many other illnesses, typically during the spring, summer and fall months.

Lyme Disease Transmission

Vector-borne diseases are diseases transmitted by mosquitoes, ticks, and fleas. Lyme disease is the most common vector-borne disease in the United States. Here in the upper midwest, Lyme disease is transmitted to humans through the bite of deer ticks infected with the spirochete Borrelia burgdorferi.

According to the Illinois Department of Public Health, the deer tick is “established” in 26 counties in Illinois. In addition, Lyme disease cases are frequently reported following tick exposure in these Illinois areas:

• Wooded areas near the Mississippi River in Rock Island County
• Along the Mississippi River in the northwest section of Carroll County
• Jo Daviess County
• Central part of Ogle County

In Iowa, deer ticks have been expanding their range, especially along the Mississippi and Missouri Rivers. According to the Iowa Lyme Disease Surveillance Program, many counties in central and eastern Iowa are known to harbor infected ticks – nearby counties include Des Moines, Iowa, Johnson, Linn, Louisa, Muscatine, and Scott. The highest numbers of Iowa-reported Lyme disease cases have been in Allamakee, Clayton, and Iowa counties.

Lyme disease is becoming more common in suburban areas with large deer populations. You may come into contact with ticks during outdoor activities around your home, or when walking through vegetation such as tall grass or other plants, leaf litter, or shrubs. Deer ticks infest humans, white-tailed deer, white-footed mice, prairie voles, birds, pets, horses, livestock, and other mammals. Ticks live in moist and humid environments – especially near wooded or grassy areas.

Signs and Symptoms

Most people do not see the tick that has bitten them. A deer tick is very small – about the size of a poppy seed – in the summer. At 3-30 days, post-tick bite, a rash will occur in approximately 70-80 percent of infected persons. The rash begins at the site of the tick bite, and may spread. The rash is called Erythema migrans (EM), or “bull’s-eye” rash (as shown in the photo). However, EM may take alternate forms – solid lesions, blue-purple hues, or crusted/blistering lesions. EM rashes may appear on any area of the body.

Other general symptoms may occur with or without the EM rash, such as fatigue, chills, fever, headache, muscle and joint aches, and swollen lymph nodes. If left untreated, the infection may spread from the site of the bite to other parts of the body, and may possibly cause:

• Additional EM rashes on other areas of the body
• Facial or Bell’s palsy; neurologic disease
• Severe headaches and neck stiffness
• Pain and swelling in the large joints (such as knees)
• Arthritis
• Shooting pains that may interfere with sleep
• Heart palpitations and dizziness due to changes in heartbeat and/or cardiac disease
• Meningitis, encephalitis, or radiculopathy

If you suspect a tick-borne illness

If you suspect that you, a family member, or even your pet may have a tick-borne illness, seek medical attention IMMEDIATELY. Tick-borne diseases can lead to SERIOUS illnesses, and delaying treatment can cause severe or life-threatening complications – even death.


The Centers for Disease Control (CDC) currently recommends a two-step process when testing blood for Lyme antibodies. Both steps can be done using the same blood sample.

The first step uses a test called “EIA” or enzyme immunoassay. If this first test is negative, no further testing is recommended. However, if this first test is positive or indeterminate, then a second test should be performed called “Western blot.” At Metropolitan Medical Laboratory, all positive and indeterminate Lyme Antibody EIA tests are automatically tested with the Western blot assay per CDC guidelines.

Results may be suggestive of Lyme disease if both the EIA and Western blot are positive. The two steps of testing are designed to be done sequentially – the CDC does not recommend skipping the first test and just doing the Western blot, since false positive results may occur.

As with serologic blood tests for other infectious diseases, the accuracy of antibody testing depends upon the stage of the disease. During the first few weeks of infection, lab tests are expected to be negative, since antibodies against Lyme disease usually take a few weeks to develop. Testing is likely to be positive 4-6 weeks after the tick bite.


Patients treated with appropriate antibiotics in the early stages of Lyme disease usually recover quickly and completely. After treatment, perhaps 10-20 percent of patients may have persistent or recurrent symptoms as part of Post-treatment Lyme disease syndrome, or PTLDS. In both Illinois and Iowa, confirmed cases of Lyme disease are reported by your physician to the local health department.


Information on prevention as well as other Lyme disease topics can be found at www.cdc.gov/lyme, or from your county or state health department.

Metropolitan Medical Laboratory, PLC is one of the largest accredited laboratories in the states of Illinois and Iowa, and has provided this community with quality laboratory services for 99 years. Visit www.metromedlab.com. Tell your doctor, “I want my lab tests to go to Metro.”