Scientists predict the number of people suffering from a little-understood type of Lyme disease could spike to almost 2 million in 2020.
The most common vector-borne illness in the U.S., Lyme disease is caused by the Borrelia burgdorferi bacterium, which is spread by infected ticks. Sufferers can have a fever, headache, chills, fatigue, joint and muscle ache and swollen lymph nodes. In many cases, patients experience an erythema migrans rash that can grow up to 12 inches around the area of the tick bite. Around 329,000 cases are thought to occur each year, although the true number of infections is thought to be higher.