Lyme disease, the infection caused by the spirochete Borrelia burgdorferi, is expected to be more prevalent this coming season—this is especially the case along the Northeastern U.S, where the bacterial organism is known to be endemic. However, it appears that this infection has been spreading more and more westward as time has passed. Data from the CDC between 2001 to 2015 shows how cases of Lyme Disease have become more and more prevalent in areas like western Pennsylvania, Virginia and North Carolina, states that previously were not seeing routine cases of this infection within the general population.

A number of reasons could explain why this infection is continuing to spread westward.  The bacteria that causes Lyme disease resides in black legged (Ixodes species) ticks which tend to be present primarily on two types of mammals—the white-footed mouse and the white-tailed deer. Both of these mammals have been noted to be spreading westward, partially due to human interference resulting in the destruction of their homes along the east coast.

In addition, changes in the weather over the past 15 years or so may also be playing a role in when and where ticks are present throughout the year, and for how long. Warmer weather, which has been more common in the Fall and Winter months as of late, may be increasing the amount of time that humans and ticks interface, which in turn could be increasing the risk for development of Lyme Disease.

In the westernmost parts of the Northeastern U.S, where people may be less savvy of Lyme symptoms, the classic signs of early Lyme disease (rashes, fever) may go unnoticed, leading to progression of the infection and more serious manifestations such as meningitis, carditis and joint swelling and pain. As Lyme disease can be cured once identified and treated, it is becoming more and more important to make sure patients are aware of the early signs of this infection—although these symptoms can often be nonspecific in nature, in the setting of a known tick bite in an area endemic for Lyme, further workup should be considered.

The best ways to minimize your risk for Lyme disease this season (which is classically present in the Spring and Summer months) is to use common sense. In wooded areas or locations with long grass (areas where ticks are more likely to be found), wearing lightweight but long-sleeved clothing will minimize the amount of exposed skin that ticks can latch onto—which in turn can reduce your risk of becoming infected. For people who have prolonged exposure to high-risk environments, using DEET, Permethrin and Picaridin sprays in conjunction with long sleeved clothing can further reduce the risk of infection. All 3 sprays are safe for pregnant women, and can be found in local stores quite readily. Lastly, during high-risk months, checking for ticks in the mirror prior to taking a shower or bath could help detect early exposure. Ticks tend to be found in the groin area, the armpits and back. If a tick is found, the ideal thing to do would be to completely detach the tick using a set of tweezers; if this can’t be done, a medical provider could assist in tick removal. If a patient sees his primary care provider within 72 hours of the tick being removed, a much shorter course of therapy may be needed.

A recent Pittsburgh Post-Gazette article focused on the complex ecosystems that contribute to fluctuations in the disease.  Dr. Neel Shah was quoted in this article. The CDC reports that about 30,000 case of Lyme are present each year in the U.S, however this number could be significantly more, in part due to the spread of the infection that we are seeing towards the west. Imperfect diagnostic tools and lack of awareness of symptoms associated with Lyme are other possible reasons. It will be difficult to predict exactly how many cases will be found this year, however the above data suggests that an increase in cases could continue, something that all physicians should be made aware of.