Other Tick-Borne Diseases
Babesiosis
What is Babesiosis?
Where is Babesiosis Prevalent?
Symptoms
Diagnosis
Treatment
Prevention & Control
How to Remove a Tick
Deer Tick Ecology
Tick species that transmit babesiosis: Deer ticks and other members of the Ixodes genus
What is Babesiosis?
Babesiosis is a malaria-like illness caused by a protozoan parasite (Babesia microti in the U.S.; other members of the Babesia genus in Europe) that invades red blood cells, and is primarily transmitted by the deer tick Ixodes scapularis and possibly other related Ixodid ticks.
In Europe, reported fatal cases of babesiosis have occurred mostly in patients whose spleens have been removed, rendering them more vulnerable to infection. The offending parasite in these cases have been either B. divergens or B. major, to which humans (with spleens intact) are thought to be naturally resistant. In the U.S., reported fatal cases have occurred in patients both with and without spleens; B. microti may be a more virulent agent to which humans are not naturally resistant. However, while many in the U.S. who are exposed to the parasite do suffer severe symptoms, such cases often are self-limiting and are eventually resolved with treatment; fatalities generally are limited to elderly patients with compromised immune systems.
Approximately 200 cases of babesiosis have been reported in the U.S. since the first human case was recognized on Nantucket Island (off the coast of Massachusetts) in 1968.
Where is Babesiosis Prevalent?
The deer (black-legged) tick in the Northeast and upper Midwest, and the Western black-legged tick on the Pacific coast are the primary carriers.
A majority of reported cases occur during the summer months along the immediate coast and off-shore islands of the Northeast.
Symptoms
The symptoms of babesiosis normally begin about a week after a tick bite with a gradual onset of malaise, anorexia and fatigue. This is followed several days later by high fever, drenching sweats, muscle pain and headaches. As with malaria, these symptoms can continue over a protracted period or can abate, then recur.
Diagnosis
Diagnosis involves examining blood smears and recognizing the characteristic "ring" form taken by the Babesia parasite within the red blood cells of the patient.
Treatment
Recommended treatment is a seven-day course of oral quinine plus clindamycin under the careful supervision of a physician. Fatigue, malaise and a low grade fever may persist for weeks or months after treatment has been completed.
