Rocky Mountain Spotted Fever

• Caused by the bacteria Rickettsia ricketsiae • Carried by Dermacenter (hard or dog) ticks • Untreated, the mortality is very high • The disease is usually characterized by a fine skin

rash, high fever, headaches and muscle pain• Doxycycline and chloramphenicol are very

effective in treating the disease • Is less common on Nantucket than previously,

probably because the dog ticks are less common

Babesiosis

• Caused by the intracellular parasite Babesia microti• Carried by the black legged (deer) tick• The babesia are inoculated into the skin by the bite of the tick and then

get into the bloodstream• The organism multiplies within red blood cells in a manner similar to

malaria• Most cases are self limited in otherwise healthy persons but may be

severe in those who are immunosuppressed or without a spleen• May be life-threatening • Symptoms include fever, chills, muscle and joint pains, nausea,

vomiting and fatigue • Treatment includes atovaquone plus azithromycin or clindamycin plus

quinine

Anaplasmosis(Ehrlichiosis)

• Caused by Anaplasma phagocytophilum• Carried by the black legged (deer) tick • Enters the bloodstream after a tick bite and concentrates in

the neutrophilic white blood cells • Causes fever, nausea, headache, muscle pain, reduced

white blood cells and platelets and liver inflammation • Rarely fatal (<1%) and responds well to treatment with

doxycycline or rifampin• Diagnosed by finding a rise in antibodies to the organism

or rarely by observing the organism in white blood cells

Lyme disease

• Caused by Borrelia burgdorferi • Carried by the black legged (deer) tick • The bacteria are inoculated into the skin by a tick bite,

replicate locally and then disseminate • The organism may localize in joints, the nervous system or

heart causing symptoms in these organs • May cause a skin rash (often a target-shaped lesion),fever,

chills, muscle pains, facial palsy, or heart irregularities• It may also lead to immunologic reactions that can cause

symptoms of arthritis

Lyme disease continued

• The arthritis is rarely if ever destructive • The disease rarely if ever causes mortality • Diagnosis of early disease is usually made by observing the typical

skin rash in the presence of the above symptoms• Antibody titers don’t rise until later in the disease (weeks)• Diagnosis is made by identifying several different antibodies to

bacterial components on a “Western blot test” later in the course• Treatment with doxycycline, amoxicillin or other drugs is highly

effective in early disease.• Ceftriaxone is usually used for disease in the central nervous system

and is often used to treat suspected treatment failures