Lyme disease is on the rise in the United States, but not in the areas where it is most commonly found. Lyme disease can be contracted from deer ticks that burrow into the person's skin. Ticks get the disease from white-footed mice and pass it on to humans and animals that they bite. It's common in the Northeast and mid-Atlantic as well as some parts of the upper Midwest, but the rising rates of transmission are not entirely in these areas.
The CDC tracks cases of Lyme and has done so since 1991 when it became a nationally notifiable condition. When a patient tests positive for Lyme, their doctor reports it via local health boards, which will pass the information on to state authorities, who then pass it on to the federal government. In this way, the disease can be tracked from where the patient lives, and local, and state figures can be kept current. The disease can be mild, with flu-like symptoms or it can be severe with lasting neurological deficits, fatigue, joint inflammation, mental fog, and disability. It's treated with antibiotics, but there are some patients who don't respond well to treatment or have symptoms that last beyond the course of antibiotics. There is no vaccine to prevent Lyme disease
In the latest CDC report on the spread of the disease, figures from the reporting period of 2008-2015 showed that 275,589 cases of Lyme disease were reported to CDC. Of those 208,834 cases were confirmed and the remaining 66,755 were classified as probable. While overall, that represents an increase in cases, in the areas that are considered high incidence, rates have remained relatively stable or have decreased slightly. There are fourteen states that are considered "high incidence" for Lyme. For the purposes of the CDC classifications, the high incidence is anywhere there are greater than ten cases per 100,000 residents. The newest data, however, shows that eleven "low incidence" states that border these high-risk areas have reported a significant increase in cases, indicating that the disease is on the move into places where it previously was not a huge problem.
Lyme is typically found in young children and older adults, with slightly more men getting it than women. In the states where it's increasing, however, the patients are not the same. More women are being infected than men. In cases that were classified as "probable," the patients included more women and were older than the median age of patients in high incidence states.
What this means for states that are showing an increase in Lyme cases is that health professionals must be vigilant in examining patients and not discount symptoms of Lyme just because their state is not historically one of the areas where cases have always been high. Also, not every case of Lyme presents the same way. While the bullseye rash near a tick bite is a classic sign of Lyme, a patient can still have the disease without the rash.
The higher incidence of Lyme in humans coincides with the amount of I. scapularis ticks, which carry the disease. These ticks have been found in states as far south as Florida, so it's definitely on the move. Wherever you live, it's important to take precautions in wooded areas and around marsh areas and areas with tall grass. Covering up well, including long pants and socks is a good idea, to keep ticks off the skin. Always check children and pets as well for ticks. The video below has further information; take a look and be careful out there. A map indicating high incidence states and neighboring states can be found here in Figure 2
