Common Tick Diseases

Ticks can transmit a variety of diseases. Lyme disease is transmitted to humans and animals by the deer tick (a.k.a. the black-legged tick) and the related Western black-legged tick. It now constitutes more than 95% of all tick-borne diseases in the United States, far outpacing Rocky Mountain spotted fever, tularemia, arboviral encephalitis, plague and has been reported in 49 states and Washington D.C. Let's take a closer look at the most common tick-borne disease: Lyme

Lyme disease

Lyme disease or Lyme borreliosis is the most common tick-borne disease in North America, and the fastest-growing infectious disease in the United States. It is named after the town of Lyme, Connecticut, where a cluster of cases was first identified in 1977, although clinical features of the disease had been described in Europe as early as 1909. Although Lyme disease has now been reported in 49 of 50 states in the U.S, almost all reported cases are confined to just five geographic areas of the country: New England, Mid-Atlantic, East-North Central, South Atlantic and West North-Central.


The cause of Lyme disease is a bacterial infection, brought about by the deer tick. The disease varies widely in its presentation, which may include a rash and flu-like symptoms in its initial stage, followed by musculoskeletal, arthritic, neurological, psychiatric and/or cardiac manifestations. Early detection and prompt antibiotic treatment most often result in an excellent prognosis. However, early detection is difficult when the characteristic rash is not present, and even those who are diagnosed and treated early may remain symptomatic. Delayed or inadequate treatment may often lead to late stage Lyme that is disabling and difficult to treat.

Other associated tick-borne diseases

Babesiosis is a rare and severe tick-borne disease caused by various types of Babesia, a microscopic parasite that infects red blood cells. This disease is seen most often in children under the age of 15, and adults over the age of 50. Individuals who have other illnesses find that it is harder for them to fight off the germs. Babesiosis is spread by the bite of an infected tick – usually the American deer tick. The signs and symptoms are generally flu-like in nature, most often fever and fatigue. Some individuals show no signs of infection. This disease may be treated with antibiotics.

Ehrlichiosis is a relatively new disease and much like other tick borne diseases. This disease is transmitted to humans and animals by the bite of a tick – usually deer ticks. Individuals may become symptomatic and include fever, intense fatigue, muscle and joint pain and chills. This disease is easily treated with antibiotics.

Southern Tick-Associated Rash Illness (STARI) is the name that the Centers for Disease Control and Prevention (CDC) has given to a newly recognized tick-transmitted disease that produces a rash similar to, and often indistinguishable from the rash caused by Lyme disease. The tick which produces this bite is the Lone Star tick. STARI occurs primarily in the Southeastern and South-central United States and is sometimes referred to as "Lyme-like illness." This disease is not yet well-defined.