Tick-Borne Diseases

Tick-borne diseases are becoming a serious problem in this country as people increasingly build homes in formerly uninhabited wilderness areas where ticks and their animal hosts live. Tick-borne diseases can be caused by viruses, bacteria, or parasites. Most people become infected through tick bites during the spring and summer months.

Rocky Mountain spotted fever, a bacterial disease transmitted by the dog tick, was first identified in 1896. It still exists, although now it can be easily treated. Since then, researchers have identified many new tick-borne diseases.

Tick-borne diseases can be found throughout the United States. For example, Lyme disease, first discovered in Connecticut in the early 1970’s, has since spread to every state except Hawaii.

One of the newest tick-borne diseases to be identified in the United States is called Southern Tick-Associated Rash Illness (STARI). This disease has a bull’s-eye rash similar to that found in Lyme disease, which is caused by bacteria transmitted by the deer tick. Although researchers know that the lone star tick transmits the infectious agent that causes STARI, they do not yet know what microbe (germ) causes it.

Ticks transmit ehrlichiosis and anaplasmosis, both bacterial diseases. Babesiosis is caused by parasites carried by deer ticks. These diseases are found in several states.

Tularemia, a less common tick-borne bacterial disease, can be transmitted by ticks as well as other vectors (carriers) such as the deer-fly. Public health experts are concerned that the bacterium that causes tularemia (Francisella tularensis) could be used as a weapon of bioterrorism.

Tick-borne disease can usually be prevented by avoiding places where ticks often live, such as dense woods and brushy areas. Using insect repellents containing DEET (for the skin) or permethrin (for clothes), wearing long pants and socks, performing tick checks, and promptly removing ticks also will help prevent infection from tick-borne microbes.

Scientists are searching for better ways to diagnose, treat, and prevent tick-borne diseases. They are also looking for ways to control the tick populations that transmit microbes.