Arthropods and Bacteria

Rickettsiae are,,,

intracellular, are transmitted by arthropods, and is most likely to cause rocky mountain spotted fever

Where does Rickettsiae multiply to cause multisystem infections?

the vascular endothelium causing vasculitis in skin, CNS, and liver

Where does Rickettsia rickettsii grow?

in the cytoplasm of the eukaryotic cells

Where is Rickettsia rickettsii maintained?

in the rodent host (RH)

What kind of transmission occurs in ticks of Rickettsia rickettsii ?

transovarian

What 3 hard ticks are associated with Rickettsia ricketsii?

dog tick, brown dog tick, and wood tick

What disease is R. ricketsii most likely to cause?

rocky mountain spotted fever

What is the hallmark disease of R. rickettsii?

macular rash after 3 days (wrist, arms, ankles)

What is the treatment for R. rickettsii?

doxycycline

How is R. rickettsii diagnosed?

microimmunofluorescence

How is Mediterranean spotted fever transmitted and what is it caused by?

it’s transmitted by Rhipicephalus sanguineus (dog ticks) and is caused by Rickettsia conorii

How is Epidemic typhus trasmitted and what is it caused by?

it’s transmitted from person to person by Pediculus humanus and is caused by Rickettsiae prowazekii

Where does Rickettsiae prowazekii multiply?

in the gut epithelium of the louse and is excreted in the feces when louse bite humans

R. prowazekii can’t manifest unless what?

human is infected with lice

Epidemic typhus can cause what kind of clinical features?

flu-like symptoms and neurological involvement (80%)

How is Scrub typhus transmitted and what is it caused by>

transmitted to humans by trombiculid mites and is caused by Orienta tsutsugamushi

What is the clinical symptoms of scrub typhus?

with fever and and eschar (common in vietnam; far east)

Should you culture rickettsiae?

no, it’s dangerous and not attempted; serological test are used

What is the treatment of rickettsiae?

tetracyclines (no vaccine)

What is Francisella tularensis?

very small, strictly aerobic coccobacillus and facultatively intracellular pathogen

Which animals are most commonly associated with type a francisella tularensis infections?

Rabbits and hares

Where is type A F. tularensis restricted to?

North America

What does F. tularensis inhibit?

phagosome-lysosome fusion

What is the most common form of tularemia (F. tularensis)?

Ulceroglandular tularemia

What is oculoglandular tularemia?

inoculation into the eye which causes painful conjunctivitis with regional lymphadenopathy

How is pneumonic tularemia transmitted?

inhalation of infectious aerosols

How is F. tularensis treated?

Gentamicin (no vaccine available)

What is the causative agent of Q fever?

Coxiella burnetii

How does human infection of C. burnetii occur?

after inhalation; ticks don’t transmit disease to humans

What are the symptoms of Q fever in severe cases?

hepatitis, pneumonia, and subacute endocarditis

Detection of immunoglobulins to phase II antigens means?

acute Q fever

Detection of immunoglobulins to phase I and II antigens mean?

chronic Q fever

C. burnetii is diagnosed by ?

serology

What is the treatment for C. burnetti?

Doxycycline; for chronic a combination of doxycycline and hydroxychloroquine (vaccine available by only for those who havent been infected before)

Recommended treatment for RMSF regardless of age or state of pregnancy is always which antibiotic?

doxycycline