Tick Borne Diseases Flashcards
What is the most common tick borne disease in the United States?
Lyme Disease
What bacteria causes Lyme Disease?
Borrelia burgdorgeri
How long must a tick be attached to someone for transmission of Lyme disease to occur?
24 - 36 hours
Where is Lyme Disease most common at in the United States?
Northeast
Most cases of Lyme Disease are transmitted by what tick?
Ixodes scapularis
(Deer Tick)
What are the 3 stages of Lyme Disease?
Stage 1: Early Localized
Stage 2: Early Disseminated
Stage 3: Late Persistent
What rash is the hallmark feature of Lyme Disease
Erythema Migrans
(Bullseye Rash)
How soon after the tick bite does the bullseye rash (erythema migrans) occur?
One Week
What are the signs and symptoms of Lyme disease that is in Stage 1: Early Localized?
Erythema Migrans (Bullseye Rash)
Viral Like Illness
- myalgias
- arthralgia
- fatigue
-headache
- with or without fever
How soon after infection of Lyme disease does Stage 2: Early Disseminated infection start?
Days - Weeks
How does Stage 2: Early Disseminated infection of Lyme disease spread throughout the body?
Hematogenous
(blood)
- causes multiple erythema migrans rash
What is the most common neurological finding in Stage 2 of Lyme disease?
Aseptic Meningitis
What is the most common peripheral neurological finding in Stage 2 of Lyme disease?
CN - VII Palsy
(bilateral facial palsy is pathognomic)
What are the most common cardiac manifestations of Stage 2 of Lyme disease?
Heart Block
Myopericarditis
Arrhythmias
How long does Lyme disease Stage 3: Late Persistent Infection take to develop?
Months - Years
What are the signs and symptoms that are seen in Stage 3 Lyme disease?
Persistent or Intermittent Arthritis (especially knee)
While chronic arthritis is uncommon due to Lyme disease, what might cause it?
Immunologic Cause
(not persistent infection)
Stage 3 Lyme disease rarely presents with neurological symptoms, if it did though, what are some things you might see?
Altered Mental Status
Mood Changes
Sleep Disturbance
How is Lyme disease diagnosed?
Exposure in an endemic area with:
- physician documented erythema migrans rash
(within 30 days of possible exposure)
- or at least one late manifestation of the disease + lab confirmation
What two lab values could be elevated in a patient with Lyme disease?
Liver Enzymes
ESR
What two-test diagnostic approach is recommend for Lyme disease?
ELISA antibody (initial)
Western Blot (confirmation)
What percentage of patients with Lyme disease will be antibody negative in the first few weeks?
Up to 50%
Should patients with non-specific symptoms without objective signs of Lyme disease have serologic testing done?
No
false (+) on screen are more common than true (+)
What is the first line treatment of Lyme disease?
Doxycycline (10 days)
What are two second line treatment options for Lyme disease?
Amoxicillin (14 days)
Cefuroxime (14 days)
What is the first line treatment for Lyme Arthritis?
Doxycycline (28 days)
What is the first line treatment for Cardiac Lyme disease?
Doxycycline - outpatient
Ceftriaxone (IV) - inpatient
Fatigue, myalgia, and cognitive difficulty that continues after the successful treatment of Lyme disease.
Post or Chronic Lyme Syndrome
Should you re-treat patients with Post or Chronic Lyme Syndrome?
No
There is no data to support an ongoing infection as the cause of Post or Chronic Lyme Syndrome. What might you consider in a patient that has successfully been treated but still presents with symptoms?
Co-infection
Misdiagnosis
(don’t retest them either fool - antibodies)
What are the four major criteria for Lyme Prophylaxis?
- Ixodes scapularis attached for 36+ hours
- More than 20% of ticks in the area have Lyme
- No contraindication to Doxycycline
- Prophylaxis can be started within 72 hours of removal
What is the treatment for Lyme disease Prophylaxis?
Doxycycline (200mg)
Single Dose
Illness that comes and goes in discrete episodes over several weeks. Characterized by abrupt onset of fever, chills, tachycardia, nausea and vomiting, arthralgia, and severe headache.
Relapsing Fever
What are some other signs and symptoms of Relapsing Fever?
Hepatomegaly
Splenomegaly
Various Rashes
High Fever + Delirium
How long do Relapsing Fever attacks usually last for?
3 - 10 days
After what time interval does Relapsing Fever occur again?
1 - 2 weeks
(Often more mild)
How many relapses might occur of Relapsing Fever due to tick-borne disease?
3 - 10 relapses
What causes Relapsing Fever?
Spirochete of genus Borrelia
What are the two forms of Relapsing Fever?
Tick-borne
Louse-borne
What form of Relapsing Fever is most commonly seen in the United States?
Tick-borne
What is the main reservoir of Tick-borne Relapsing Fever?
Rodents
Where at in the United States is Relapsing Fever most common?
Mountainous West
A CBC of a patient with Relapsing Fever might show what?
Mild Anemia and Thrombocytopenia (common)
- usually normal CBC
What blood smear tests are used to diagnose Relapsing Fever?
Wright-Geimsa Stain
Darkfield Microscopy
If you suspect Relapsing Fever but don’t see any spirochete on a blood smear, what might you do next?
PCR
What is a common sign of Relapsing Fever?
Hematuria
Post-exposure prophylaxis treatment of Relapsing Fever in endemic areas.
Doxycycline (200mg) on the first day
+
Doxycycline (100mg) x4 days
How do you treat Relapsing Fever without central nervous involvement?
Penicillin G (IV)
Ceftriaxone (IV)
- both followed by Tetracycline for 10 days
What reaction is seen in about 50% of patients after starting antibiotics for Relapsing Fever?
Jarisch-Herxheimer Reaction
What is the overall mortality rate of Relapsing Fever?
5%
Illness caused by Rickettsia rickettsii
Rocky Mountain Spotted Fever
How long must a tick remain attached to transmit Rocky Mountain Spotted Fever?
6 - 10 hours
Rocky Mountain Spotted Fever spread via the lymph and blood vessels due to what?
Increased Vascular Permeability
Rocky Mountain Spotted Fever is most commonly seen during what months?
April - September
What is the mortality rate of Rocky Mountain Spotted Fever in treated patients?
10%
Where are most cases of Rocky Mountain Spotted Fever found?
Midwest
How soon do RMSF symptoms start after the tick bite?
2 - 14 days
What are the signs and symptoms of Rocky Mountain Spotted Fever?
Abrupt onset of Fever
Headache
Rash that develops a few days later.
How does a Rocky Mountain Spotted Fever Rash present?
blanching pink Macules that become Petechiae
What is the classic triad of Rocky Mountain Spotted Fever?
History of Tick bite:
Fever
Headache
Rash
How might Rocky Mountain Spotted Fever present in the early stages?
Flu-Like
- fever
- severe headache
- nausea
- vomiting
- myalgia
- malaise
Where and when does the rash occur due to Rocky Mountain Spotted Fever?
Starts at Wrist and Ankles and Spreads Centrally
(2 - 3 days)
Palms and Soles are Characteristic
What is the fatality rate of Rocky Mountain Spotted Fever if left untreated?
Up to 73%
What can Rocky Mountain Spotted Fever cause in pregnant patients?
Spontaneous Abortion
What may need to be done before a diagnosis of RMSF is confirmed?
Empiric Broad Spectrum Antibiotics
How is Rocky Mountain Spotted Fever diagnosed?
Clinically
- skin biopsy or PCR to confirm
What is the drug of choice for treating Rocky Mountain Spotted Fever?
Doxycycline (100mg)
2x a day for 5 - 7 days
What drug is used to treat Rocky Mountain Spotted Fever in pregnant patients?
Chloramphenicol
What is the usual cause of death in patients with Rocky Mountain Spotted Fever?
Pneumonitis with either:
- respiratory or cardiac failure
Are prophylactic antibiotics recommended for Rocky Mountain Spotted Fever?
No
Tick borne illness that infects monocytes or granulocytes
Ehrlichiosis
Where is Ehrlichiosis most commonly found in the United States?
Missouri
Arkansas
Oklahoma
What is the primary reservoir of Ehrlichiosis?
White Tail Deer
Mice
What tick causes Ehrlichiosis?
Lone Start Tick
What are the signs and symptoms of Ehrlichiosis?
Malaise
Rigors
Nausea
High Fever and Headache
- possible pleomorphic rash
What are some rare but serious complications that can result from Ehrlichiosis?
Acute Respiratory Failure + ARDS
Meningoencephalitis
Acute Kidney Disease
Hemophagocytic Syndrome
Multi-organ failure
How is Ehrlichiosis diagnosed?
Clinically
- PCR is sensitive in the first week
- Indirect Fluorescent Antibody from CDC
What is the primary treatment of Ehrlichiosis?
Doxycycline (100mg)
2x a day for 10 - 14 days
What is the alternative treatment for Ehrlichiosis in pregnant women?
Rifampin
What might persist for weeks, despite the appropriate treatment of Ehrlichiosis?
Headache
Weakness
Malaise
An acquired meat allergy from a tick. Results in a delayed form of anaphylaxis caused by red meat consumption.
Alpha-gal Syndrome
What is different about Alpha-gal from other food allergies?
Alpha-gal is a carbohydrate
- most food allergies are to proteins
Where is Alpha-gal syndrome most prevalent?
Midewest
What antibody-mediated allergic reaction occurs in Alpha-gal syndrome?
IgE
How is Alpha-gal diagnosed?
Serologic testing for Alpha-gal specific IgE
