Chapter 2 Flashcards
The unique characteristic of Lyme disease is…
Erythema migrans (a bulls eye rash)
What does a tick bite look like?
It’s typically a circular red area that sometimes clears in the middle, forming a bull’s-eye pattern.
what does “cargo” mean?
pathogen or parasite
Describe “Texas cattle fever, 1889”.
T. Smith was the first to prove a vector (tick) with protozoan parasite (Babesia)
The “Borrelia bacteria associated with Ixodes scapularis ticks that caused Lyme arthritis” discovery was made when?
1981-1982
Ticks must be attached _____-______ (Ave= 48) hours to transmit bacteria
4 – 72 (Ave= 48)
In many counties, ~_____% of nymphal ticks carry bacteria.
20
what stage of ticks cause a majority of lyme disease?
nymphal ticks
when are nymphal ticks are most active?
May - July
When are adult ticks most active?
late October and early November
what is zoonoses?
diseases transmitted by animals
What is the function of the palp?
detection
what is the function of the toothed hypostome?
blood flows through here
what is the function of chelicera?
holds on (grabbing)
what is Transstadial transmission?
occurs when a pathogen remains with the vector from one life stage (“stadium”) to the next
what is Transovarialortransovarian transmission?
transmission from parent to offspring via the ovaries
which tick is bigger, male of female?
female
what is the definition of niche?
an organisms’ occupation
what is the definition of habitat?
an organism’s “address”
Lone Star tick saliva allergy causes what syndrome?
alpha gal syndrome
what is the main vector of Rocky Mountain spotted fever?
Dermacentor andersoni (american dog tick)
what is the most severe rickettsial illness of humans (rocky mountain spotted fever)?
Rickettsia rickettsii
How long is the tick transfer of bacteria in rocky mountain spotted fever?
4-10 hours
What are the 4 stages of life in ticks?
egg, larvae, nymph, adult
when was the agent for rocky mountain spotted fever discovered, and by whom?
1909 - Howard Ricketts
what is the treatment for rocky mountain spotted fever?
antibiotics -> Doxycycline and chloramphenicol used most often
Without treatment for Rocky mountain spotted fever, what is the overall mortality?
20%
With early diagnosis and treatment of rocky mountain spotted fever, mortality rates drop to less than _____%.
5%
what is an amplifying host?
is a host in which the level of pathogen can become high enough that a vectorsuch as a tick that feeds on it will probably become infectious
what is a reservoir host?
- can harbor a pathogen indefinitely with no ill effects
- A single reservoir host may be reinfected several times
- A reservoir host is usually the primary host of a pathogen.
What are the primary vectors for RMSF in the US?
Dermacentor variabilis (the American dog tick) + Dermacentor andersoni (the Rocky mountain wood tick)
what are the early symptoms of RMSF?
high fever, severe headache, myalgia, and gastrointestinal symptoms (quick, acute)
what are the late symptoms of RMSF?
rash, photophobia, confusion, ataxia, seizures, cough, dyspnea, arrhythmias, jaundice, severe abdominal pain
what is the long term sequelae of RMSF?
CNS deficits, amputations
what is typhus?
affects the Rectoendothelial System
Lyme disease is primarily transmitted by ____ _____.
Black-legged (Deer tick)
Lyme disease affect about how many people in the US annually?
500,000
what is the tick species of lyme disease on the west coast?
Ixodes pacificus
Lyme disease was first identified by who?
Willy Burgdorfer
In what state was Lyme disease first recognized?
Conneticut
What animal serves as the principal reservoir of infection of lyme disease?
white-footed mice
How often do the lyme disease ticks feed?
only 3 times -> larvae, nymph, adult
what is the causative agent (pathogen) of lyme disease? (what bacteria leads to lyme disease?)
Borrelia burgdorferi
what is a characteristic of lyme disease genome?
Large microaerophilic spirochete
What are the secondary stage symptoms?
- involve heart + nervous system
- electrical conduction to heart is impaired
- nervous system involvement leads to paralysis of facial muscles + impaired concentration
when does the the secondary stage of lyme disease begin?
2-8 weeks post rash
what are the symptoms of the third stage of lyme disease?
- arthritis
- chronic nervous system impairment
Once the bacteria is in the skin (lyme disease), what occurs?
bacteria migrate outward in radial fashion
what’s the treatment for the early lyme disease stage?
doxycycline
Ehrlichiosis disease is common in ______ locally.
dogs
what is the vector for babesiosis?
loxedes tick
what is the second most commonly reported tickborne disease?
anaplasmosis
what is the vector of Erlichiosis?
lone star tick
what is the treatment for Erlichiosis?
doxycycline
what is the treatment for babesiosis?
atovaquone + azithromycin
______ causes Babesiosis
Babesia
what is the host for Ixodes sp. in the adult tick stage?
white tailed deer
what is the host for Ixodes sp. in the larval tick stage?
white footed mouse
what are the hosts for Ixodes sp. in the nymphal tick stage?
mouse + human
If Lyme disease/babesiosis is suspected, _______/ microscopic examination of blood smears should be pursued.
ELISA
