what type of bacteria are borrelia?
spirochetes
what is the difference in appearance between treponema and borrelia?
borrelia are large enough to see with standard microscopy
what organism causes lime disease? what is its vector?
b burgdorferi
vectored by deer ticks
what is the downside of serology testing for b burgdorferi?
serology can confirm exposure but not disease and not promptly after infection?
how much time does lyme take to transmit from the vector?
24 hours
what are the three stages of lyme disease?
1) flu like with erythema migrans rash
2) musculoskeletal and/or neurologic symptoms
3) additional neurologic symptoms and arthralgias
what is post lyme syndrome? what is it caused by?
lingering fatigue, joint pain and mental status changes. caused by damage, not lingering bacteria
how is lyme disease treated?
with amoxicillin or doxycycline. give ceftriaxone if in child or pregnant woman. treat for 10-30 days only
what vectors carry relapsing fever bacteria?
louse or tick borne.
louse are more severe but tick borne are most likely seen in the US
what is relapsing fever?
high fevers with well periods in between.
what two pathogens cause relapsing fever?
borrelia recurrentis (louse) and hermsii (soft ticks)
what is the lifecycle of relapsing fever in the human body?
immediately enters the blood stream from the bite site. there is repeated rounds of bacteremia and clean up by neutralizing antibodies
why can’t the immune system immediately terminate relapsing fever?
because there is antigenic variation by the spirochetes
how is relapsing fever diagnosed?
by peripheral blood smear during febrile periods
how is relapsing fevers treated?
with tetracyclines (doxycycline)
how are relapsing fever and lyme disease avoided?
use protective clothing and deet. perform daily tick checks in at risk areas during the tick seasons
what is the Jarisch Herxheimer reaction?
a reaction following the successful treatment of any spirochete infection. It is an endotoxin response resembling septicemia
how are Rickettsia, Ehrlichia and Anaplasma transmitted? what shape are they?
transmitted through arthropod vectors
they are small cocci to short rods
how are reckettsia, ehrlichia and anaplasma treated?
with tetracycline (doxycycline)
what is a nuance of the life cycle of the rickettsia, erlichia and anaplasma?
they are obligate intracellular parasites that can only be grown in vitro in tissue culture
how do the rickettsiae diseases present?
headache, fever and body aches. may also cause a rash or eschar
what is the proper removal of a tick?
should be done with tweezers while wearing gloves. done promptly because bacteria take time to transmit
what rickettsial disease has humans as the proper host? how does this differ from others?
epidemic typhus
other rickettsial diseases are accidental transmissions to humans by vectors
where do rickettsia divide?
throughout the cell
where do ehrlichia and anaplasma divide?
they form morulae in phagocytic vacuoles
how are rickettsial bacteria identified?
all are difficult to stain and require microimmunofluorescent assay to visualize
what treatment is used for rickettsial illnesses?
tetracyclines used for adults and children, but not for pregnant women. alternately treated with chloramphenicol (rickettsia) or fluoroquinolones (ehrlichia and anaplasma)