Lyme disease poses its greatest risk to those on the Northeastern U.S. coast, a new study from the Yale School of Medicine said.
Lyme disease comes from tick bites that spread the Borrelia burgdorferi bacteria and causes flu-like symptoms along with a telltale bull's-eye rash. If not treated, Lyme disease can cause nerve damage, memory loss and paralysis of the face.
The new study focused on transmission rates in the Eastern U.S., where the disease is most prevalent, to pinpoint exactly where the greatest risk is.
Turns out the coastal region bears the brunt of disease transmission, an observation researchers hope will help in disease prevention.
There is Lyme in the west coast, mostly just some areas in [California], but it the prevalence is very low, Maria Diuk-Wasser, the study's lead author, wrote in an email. In addition, it's transmitted by another (but very similar) species of tick, Ixodes pacificus. The ecology of this tick is very different (different habitats, hosts, etc). For these 2 reasons (prevalence and ecology), we decided to focus on the east, [where] the risk is higher.
The American Journal of Tropical Medicine and Hygiene published the study in its February edition.
The study took place over three years between 2004 and 2007. Researchers dragged sheets of fabric through wooded areas in order to collect ticks. One in five collected sheets harbored ticks infected with Lyme disease.
The researchers mapped the Lyme disease prone regions in an effort to help improve prevention, diagnosis and treatment. Previously, disease cartographers created maps based on infection reports, according to the study, an approach impacted by under and over diagnosis of the disease.
The study authors said that though they collected the data several years ago, the high-risk areas likely have not changed and could be used as a baseline for future research.
The key value is identifying areas where the risk for Lyme disease is the highest, so that should alert the public and the clinicians and the public health agencies in terms of taking more precautions and potential interventions, Wasser told The Associated Press. In areas that are low risk, a case of Lyme disease is not impossible but it's highly unlikely, so the clinician should be considering other diagnoses.
The map produced by Wasser and her team shows the greatest risk for Lyme disease to be around Maryland and stretch along the coast through Maine. In addition, there is a high-risk area throughout Wisconsin and into upper Minnesota.
Lyme disease, transmitted by deer ticks, is named for Lyme, Conn., where the disease was first identified in 1975. There are a variety of symptoms, such as fever, headache and fatigue, but the classic sign is a bull's-eye rash, which can occur anywhere between three and 30 days after the tick bite. If left untreated, symptoms could progress to neurological problems, such as impaired muscle movement, inflammation of the membranes surrounding your brain, and temporary facial paralysis.
The best prevention against Lyme disease is wearing protective clothing when walking through areas where Lyme disease is prevalent; according to the Mayo Clinic. Protective clothing includes hats, long-sleeved shirts and long pants. Light colors are recommended so ticks are more visible. Lyme disease is treated with antibiotics such as doxycycline and amoxicillin for 10 to 28 days. If treated early, Lyme disease is usually curative. If left untreated, the disease can be more stubborn, and may require an antibiotic that has the ability to cross the blood-brain barrier.
The Centers for Disease Control and Prevention counted more than 30,000 confirmed cases of Lyme disease in 2010, 90 percent of which fell in the high-risk areas indicated by this study's map.