Ehrlichiosis, Anaplasmosis, Rocky Mountain Spotted Fever Flashcards
Ehrlichiosis
Usually found in the southeast and south central US from the Eastern Seaboard to Texas
Lone Start Tick has been implicated in transmission
Upper midwest is associated with the Ixodes scapularis tick for transmission
Transmission through blood transfusions and possibly transplants
Symptoms develop 1-2 weeks after tick bite, 50% do not recall bite
Can be fatal if not properly treated even in previously healthy people.
Usually receiver quickly on outpatient abx. Severe infections may require IV ABC, prolonged hospitalization and ICU. Severity increases with immunocompromised patients.
Ehrlichiosis Clinical Presentation
Difficulty breathing or bleeding disorders in severe cases. Mortality rate is 1.8%.
Fever, chills, headache, malaise, myalgias, GI symptoms, confusion, conjunctival injection, rash (usually in children)
Ehrlichiosis Lab Testing
Findings- thrombocytopenia, leukopenia, anemia (later in illness), mild to moderate elevated LFTs
Detection of DNA via PCR is most sensitive during the 1st week of illness, sensitivity decreased after administration of tetracycline antibiotics
Ehrlichiosis Treatment
Doxycycline 100mg BID until 3 days after fever resolves and until evidence of clinical improvement, minimum 5-7 days- may treat only based on clinical suspicion.
Anaplasmosis
Usually in upper midwest and northeast US in areas with Lyme disease
Similar presentation to Ehrlichiosis, but transmitted by two different species of ticks and usually occur in different geographic areas.
Anaplasmosis Symptoms
Fever, shaking chills, severe headache, malaise, myalgia, GI symptoms, cough, rash (rare)
Anaplasmosis Lab Findings
Mild anemia Thrombocytopenia Leukopenia Mild to moderate LFT elevations May see in blood smear
Detection of DNA in PCR most sensitive in 1st week of illness, sensitivity decreases after antibiotics are started.
Anaplasmosis Treatment
Clinical suspicion is enough to treat disease, do not wait for labs to return if disease is strongly suspected.
Doxycycline 100mg BID x 10-14 days (Adults)
Children 2.2mg/kg/day, max dose 100mg BID, given twice daily
May give if under age 8 due to higher risk of death.
Rocky Mountain Spotted Fever
Rare in NY
Spread by American dog tick, rocky mountain wood tick, brown dog tick.
Can be spread through blood transfusions or organ transplant
May through August
Most severe rickettsiosis in US
Rapidly progressing and can be fatal in days
RMSF Symptoms
3-12 days after tick bite, many patients do not recall bite.
Early symptoms (1-4 days)- fever, headache, GI symptoms, and pain, myalgia, rash (after fever), edema around eyes and back of hands.
Late Illness (Day 5 or later)- AMS, coma, cerebral edema, respiratory compromise, necrosis, amputation, multiorgan system damage.
RF for severe illness- delayed treatment, children <10, G6PD deficiency
<50% of patients develop rash in the first 3 days of illness
RMSF Lab Results
Thrombocytopenia, hyponatremia, elevated LFTs
RMSF Vasculitis
Bacterial infects the endothelial cells that line the blood vessels causing vasculitis. Bleeding/clotting may occur.
Long term health problems may occur- neurological deficits, internal organ damage, vascular damage requiring amputation
RMSF Treatment
Should not delay treatment for laboratory confirmation- treat if suspected
Treatment is doxycycline for all ages. Most effective if started in the first 5 days of illness.
Fever will usually subside 24-48 hours after treatment is started.
Adults- doxy 100mg BID, children under 45kg 2.2mg/kg/day bid
Minimum 5-7 days, at least 3 days after fever subsides.
Chloramphenicol is only alternative drug- higher risk of death.
Sulfa drugs may worsen course and increase likelihood of death.
No prophylaxis is recommended.
RMSF Prevention
Walk in center of trails
Treat clothing/gear with 0.5% permethrin
Always check clothing, tumble dry on high heat x10 minutes after coming inside.
Shower within 2 hours of coming indoors, body checks.
Remove and dispose of any ticks immediately.
