Tick Borne Disease

Question 1

Lyme disease

Answer 1

Most common vector-borne disease in the US. Caused by bacterium Borrelia burgdorferi and rarely Borrelia Mayo I. Transmitted to humans through bite of infected black-legged ticks.

Question 2

Ehrlichiosis AND Anaplasmosis-common symptoms

Answer 2

Fever
Headache 
Chills
Malaise
Muscle pain
N/V/D
Confusion
Conjunctival injection (red eyes)
Rash (in up to 60% of children, less than 30% of adults)

Question 3

Ehrlichia and Anaplasma diagnostics and management

Answer 3

• immunofluorescence antibody ( iFA) test for IgG and IgM to Ehrlichia and anaplasma…cross sensitivity among agents, usually requires a confirmatory sample 2-4 weeks after a positive test to confirm results
• PCR IS THE TEST OF CHOICE -most sensitive during the first week of illness

POSITIVE RESULT IS MORE MEANINGFUL THAN A NEGATIVE RESULT-ANTIBODIES frequently negative in the first 7-10 days of an acute illness.

Question 4

Treatment anaplasmosis ehrichiosis and spotted fever:

Answer 4

Doxycycline 100mg BID (adults) weight based for kids (2.2mg/kg, BID). Usually 10-14 days.

Clinical suspicion of any of these diseases is sufficient to begin treatment. Delay in treatment may result in sever illness and even death.

Question 5

Lyme disease background:

Answer 5

Most infections with Borrelia species is not usually transmitted within the first 48-72 hours of tick attachment.
-likelihood of transmission increased if tick engorged and/or has been attached for at least 72 hours.

Often begins with rash then headaches arthritis neurological sequelae

Question 6

Lyme disease diagnostic test

Answer 6

• clinical diagnosis
• false negatives early in disease, false positives in population
• serology is used to confirm antibodies to B. burgdorferi and other species

TWO STEP SEROLOGIC TESTS

1. Enzyme linked immunosorbent assay (ELISA)-IF POSITIVE PROCEED TO STEP 2
2. WESTERN BLOT ASSAY IS CONFIRMATORY.

IgM appears in 2-4 weeks, peaks at 6-8 weeks then declines to low levels in 4-6 months

IgG negative at 2-4 weeks, appears at 6-8 weeks, peaks at 4-6 months, remains elevated but at lower levels.