Ticks are parasitic, spider-like pests that typically inhabit wooded areas. They feed on animal blood, attaching to the skin to take a meal. Ticks endanger humans due to the risk of acquiring an infectious disease through a bite. Tick-borne diseases can cause serious illness; some are potentially life threatening. Early diagnosis and treatment helps prevent long-term complications associated with tick-borne diseases.
Rocky Mountain Spotted Fever
Rocky Mountain spotted fever is a serious infectious disease carried by Rocky Mountain wood ticks and American dog ticks. The bacterium Rickettsia rickettsii causes Rocky Mountain spotted fever. Initial flu-like symptoms appear approximately five to 10 days after a bite from an infected tick, including high fever, chills, severe headache, muscle pain, nausea and vomiting. "The Merck Manual for Healthcare Professionals" reports that a rash typically erupts within one to six days after the onset of fever. The rash begins as pink patches, which gradually darken. Purple spots, representing minute blood clots in the skin, develop within the rash-covered skin areas. Rocky Mountain spotted fever infection can spread to the brain, lungs and other body organs. Antibiotics are the mainstay of treatment. According to the Centers for Disease Control and Prevention, the fatality rate for Rocky Mountain spotted fever is up to 20 percent in untreated patients and 5 percent in those who receive treatment.
Lyme Disease
The bacterium Borrelia burgdorferi, carried by black-legged ticks, causes Lyme disease. The course of Lyme disease varies greatly from person to person. The Centers for Disease Control and Prevention reports that 70 to 80 percent of people infected with Borrelia burgdorferi develop a characteristic skin rash termed erythema migrans. The rash begins at the site of the tick bite and expands outward. Flu-like symptoms, including headache, fatigue, low-grade fever, body aches and swollen glands, may accompany the skin rash. Untreated infection may progress with the development of stiff neck, facial muscle weakness, heart rhythm abnormalities and joint pain. Long-term infection with Borrelia burgdorferi can cause arthritic symptoms in the knees, hips and shoulders in up to 60 percent of patients, notes the Centers for Disease Control and Prevention. Antibiotic treatment at any stage of Lyme disease leads to resolution of the illness in the overwhelming majority of patients.
Babesiosis
The microscopic parasites Babesia microti and Babesia divergens cause the tick-borne illness babesiosis. The Centers for Disease Control and Prevention notes that flu-like symptoms, including fatigue, high fever with chills and sweats, headache, muscle and joint aches, nausea and loss of appetite, can occur weeks to months after infection. Babesia parasites infect red blood cells, which can trigger premature destruction of the red blood cells by the liver and spleen, leading to anemia. Prior removal of the spleen, a weakened immune system and chronic liver or kidney disease increase the risk for severe anemia due to babesiosis. Antimicrobial medications are used to clear babesiosis infections.
References
- Centers for Disease Control and Prevention: Rocky Mountain Spotted Fever, Questions and Answers
- Merck Manual for Healthcare Professionals: Rocky Mountain Spotted Fever
- Centers for Disease Control and Prevention, MMWR: Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever, Ehrlichioses, and Anaplasmosis--United States
- Centers for Disease Control and Prevention: Lyme Disease Symptoms
- Merck Manual for Healthcare Professionals: Lyme Disease
