There are several diseases spread through the bite of a tick. Tick-borne diseases are actually the most common vector-borne disease type in the United States, though they infect relatively few numbers of people per year. Tick-borne diseases occur in every region in the United States and occur primarily in the summer and fall.
Transmission
Ticks must take a blood meal in order to develop properly. When a tick begins to take its meal from an animal or human infected with a pathogenic bacteria, it becomes infected. It transmits the disease to another human or animal with every subsequent blood meal that it takes via its infected saliva.
Symptoms
The symptoms that one presents when infected with a tick-borne disease don't vary much initially. Initial symptoms may be fever, head and body aches and malaise. Some of these diseases also cause vomiting and diarrhea.
Prevention
Tick-infested areas such as wooded and grassy areas should be avoided. Wear long sleeves and pants when venturing into these areas and an insect repellent with 10-30 percent DEET should be worn. When returning from a wooded or grassy area, perform tick checks on yourself and your children.
Ticks can remain on the skin for hours after they first attach themselves; removal is best facilitated with a pair of tweezers or in the shower by rubbing with a washcloth.
Lyme Disease
Lyme disease occurs when a person is bitten by an infected Deer tick. This disease is most likely to be found in the Northeast, North Central and the Pacific Coast regions of the U.S. Lyme disease is the most common tick-borne disease in the U.S. with 29,000 cases reported in 2008, according to the CDC. Initial symptoms include fever, headache and a characteristic rash. If left untreated Lyme disease will cause neurological and cardiac abnormalities sometimes months to years after initial infection.
Rocky Mountain Spotted Fever
Rocky Mountain spotted fever (RMSF) is the most severe tick-borne disease in the United States. RMSF occurs primarily in the Southeast and Atlantic coastal regions of the U.S. There are few cases reported in the Rocky Mountain region where the disease was first discovered. This disease is relatively rare; the CDC receives fewer than 1,200 reported cases each year. A doctor that receives a patient with fever, rash and a tick bite should recognize this combination of symptoms as indicative of RMSF. The disease can be severe and most patients end up hospitalized.
Tick-borne Relapsing Fever
Tick-borne relapsing fever (TBRF) is characterized by recurring (relapsing) episodes of fever. This disease is mainly found in visitors of cabins and vacation homes in forests of the Western U.S. at elevations at and above 8,000 feet. About 25 cases are reported every year. Symptoms include recurring fever, generalized body aches and nausea.
Ehrlichiosis
Ehrlichiosis is a relatively new disease; the first human case was described in the mid-1980s. A bite from an infected Lone Star tick can cause infection. Incidence of this disease primarily corresponds with the geographic distribution of the Lone Star tick, which is found in the eastern, southern and South-Central regions of the U.S. People with this disease may be mildly to asymptomatic.
Agents of Bioterrorism
Two tick-borne diseases have been flagged by the government as potential agents of bioterrorism. Tularemia and Q fever, both of which are normally rare diseases, have been flagged because of their durability and communicability. Tularemia is normally spread via the bite of a tick infected by the bacterium Francisella tularensis. If these bacteria are breathed in through the air, severe respiratory symptoms, including pneumonia and infection, will occur.
Q fever, a category B agent, has been flagged as a potential agent for bioterrorism because of its communicability and durability; it can withstand extremely dry and hot conditions. A single inhaled bacterium can cause infection in a person potentially leading to pneumonia and liver complications.
