Tick lecture Flashcards
what are the general sx of tick-borne diseases?
fever/chills, aches/pains, +/- rash
what tick disease is a multisystem inflammatory disease
lyme disease
how does lyme disease spread
by tick (“Ixodes”) bites via spirochetes (“burrelia burgdoferi”)
what is the preferred host of ticks?
white tailed deer
what is the life cycle of the tick?
egg –> 6-legged larva –> eight-legged nymph –> adult
at which stage of the tick life cycle do ticks feed on humans? what time of year does this occur?
nymph stages - may to july
how long do ticks have to feed on you for to transmit lyme disease?
at least 24 hours
why is it that we don’t discover the tick when it first starts feeding?
small, and ticks have barbed beaks that release anesthetics once they penetrate the skin
what diseases are transmitted by the deer tick (ixodes scapularis)?
anaplasmosis, babesiosis, and lyme disease
when a person is bitten by a tick, what almost always develops and isn’t indicative of a tick-borne disease?
a small raised red itchy bump at the site of the bite
what disease does the agent anaplasma phagocytophilum carry?
anaplasmosis
what is the animal reservoir for anaplasmosis?
deer and white-footed mouse
what is anaplasmosis/HGA?
human granulocytic anaplasmosis - a bacterial infection that infects WBCs (granulocytes)
how long does it take for a tick to transmit anaplasmosis?
24-48 hours
what other disease does anaplamosis very closely mimic?
ehrlichiosis
What is STARI?
southern tick associated rash illness of unknown cause
what are the sx of STARI?
rash similar to lyme disease, but no arthritic, neurologic, or chronic sx
what tick carries STARI and where can it be found?
the lonestar tick - in southeast america
how long is the incubation period for anaplasmosis once contracted?
1-2 weeks
what are the sx of anaplasmosis?
fever/chills, HA, malaise, myalgias, arthralgia. may have cough, stiff neck, GI upset
what lab findings will you find with anaplasmosis?
mild anemia, thrombocytopenia, leukopenia with left shift, elevated LFTs
how do you dx anaplasmosis (and babesiosis)?
PCR
how do you treat anaplasmosis?
doxycycline
what is babesiosis?
a parasitic infection from a tick, caused by protozoa, and infects RBCs and causes hemolysis
what is the reservoir for babesiosis?
rodents and small mammals
where does babesiosis occur?
northeast coast of US
how long is the incubation period for babesiosis?
1-3 weeks.
if from infusion, 6-9 weeks
what are the sx of babesiosis?
fever/chills/sweats, myalgias, arthralgias, fatigue, N/V (surprise!)
what will you find on physical exam of babesiosis?
splenomegaly, hepatomegaly, jaundice
what are the risk factors for babesiosis?
over 50, immunocompromised
how do you treat a person with asx babesiosis?
none, monitor 4-6 weeks if you want
how do you treat babesiosis?
clindamycin/quinine or atovaquone/azithromycin
what are the sx of lyme disease?
erythema migrans (bullseye rash), muscle/joint pain, fatigue, chills/fever, HA, swollen lymph nodes
what is the early presentation of lyme disease in a person who doesn’t have a rash?
arthralgias, HA (occipital), paresthesias
what is lyme carditis?
a fluctuating AV block caused by lyme disease
what neurological sx might you get with lyme disease?
cranial neuritis AKA bell’s palsy,
lymphocytic meningitis,
radiculoneuritis
what sx show up in late lyme disease (> 6 mos)
arthritis and more severe neuro sx
how do you dx lyme disease?
serologic tests - confirm dx;
Elisa and Western blot
what can you give in the early phases of lyme disease that might prevent seroconversion?
abx
what Ab do you look for if
IgM and IgG
what Ab do you look for if >4 weeks of illness?
IgG
how long do lyme Ab stay in blood?
many years - can’t determine relapse vs reinfection
how do you treat lyme disease?
doxycycline
if a person has extremely severe lyme disease sx, what do you treat with?
IV ceftriaxone
what are the 3 long-term sequellae of treated lyme disease?
- persistent arthritis (usually knee) for 4-5 years
- residual neurologic impairment
- post-lyme syndrome for >6 months with MSK pain, cognitive complaints, fatigue
if a person is having lyme symptoms and has a positive lyme titer, does that mean lyme is causing the symptoms?
No. Most people who get lyme have no symptoms. If a person has non-specific symptoms with a + lyme titer, it doesn’t necessarily mean that the person is having these sx due to lyme.
what are the 4 conditions when you would give tick bite prophylaxis (e.g. a person was bitten but doesn’t have lyme sx)
(1) tick has been identified as an engorged deer tick and has been attached over 36 hours
(2) it’s a high exposure area
(3) it has been within 72 hours of the bite
(4) doxy is not c/i in the patient
what does the bacteria rickettsia ricketsiae cause?
rocky mountain spotted fever
what animals carry rocky mtn spotted fever?
dogs
if untreated, what is the prognosis?
high mortality
what are the sx of rocky mtn spotted fever
a fine skin rash, high fever, HA, muscle pain, GI sx
what 2 drugs do you use to treat rocky mtn spotted fever?
doxycycline and chloramphenicol
where is the MC place to get rocky mtn spotted fever?
maryland
what months do cases of rocky mtn spotted fever occur?
april to sept
in what population is rocky mtn spotted fever MC in?
children, males
what are long-term sequellae of rocky mtn spotted fever?
CNS issues, amputations, death
which type of tick transmits tularemia?
american dog tick, lone star tick, and rocky mountain wood tick
how can tularemia be transmitted?
deer fly bites, inhalation, ingestion, skin contact with infected animals
what animals carry tularemia?
rodents
what vectors carry tularemia?
ticks, biting flies, mosquitoes
is tularemia common
no
how can you contract tularemia?
ingestion, inhalation, direct contact, arthropods, animal bites
can you spread tularemia person to person?
no
if this is so rare, why are we talking about it?
HIGHLY infectious; tick-borne; bioterrorism agent
what will you see on PE with tularemia?
ulcers
how do you dx tularemia?
PCR
how do you tx tularemia?
streptomycin, gentamicin, FQs
what is the definition of relapsing fevers?
recurrent cycles of febrile episodes, separated by asx intervals of apparent recovery
what organism causes relapsing fevers?
borellia
what are the 3 main causes of relapsing fever?
(1) louse-borne relapsing fevers
(2) trench fever
(3) epidemic typhus
what are the 3 types of lice?
(1) head lice
(2) body lice* spreads disease!
(3) pubic lice
how do you pull a tick off of the skin?
tweezers, apply antiseptic to the bite
can you touch a tick with your bare hands?
you shouldn’t (even though my mom just picks them off my dogs with her fingers and pops it between her fingernails……. ew)
