Vector-borne and zoonotic bacterial infections Flashcards
Rickettsia species causes
Spotted fevers and typhus
Erlichia chaffeensis causes
Human monocytic ehrlichiosis
Anaplasma phagocytophilum causes
Anaplasmosis
Borrelia burgdorferi causes
Lyme disease
What does borrelia burdorferi look like?
Spirochete, hard to visualize with gram stain because it’s so small.
Lyme disease rash called
Bulls eye or erythema migrans
Can lyme disease affect the heart?
Yes causes heart block.
What is the vector for B. burgdorferi?
Ixodes scapularis (blacklegged tick).
Where is B. burgdorferi common?
Northeast
Reservoir for burgdorferi?
White footed mice, which are bitten by Ixodes scapularis
Why are deer significant in lyme disease?
Because they keep adult ticks (that are carrying Borrelia burgdorferi) alive
What stage of ixode development is most significant for causing disease?
Nymph
Phases of lyme disease
Early localized: characterized by erythemia migrans and mild systemic symptoms (fever, chills).
Early disseminated: Meningitis, Bell’s Palsy, heart block, rash.
Late disease: Arthritis on knees, chronic neurological problems
How to diagnose?
Clinical picture, IgG and IgM antibody tests.
How to treat lyme disease
Oral doxycycline (amoxicillin in children), or if it gets serious, cefriaxone.
Leptospirosis caused by
Leptospira species. Comes from raccoon urine that is picked up by dogs, can be transmitted to humans.
Diagnosis of leptospirosis?
Serology, look for serum antibodies
Treatment of leptospirosis
Penicillin
Symptoms of leptospirosis
Hematogenous spread causing fever and headache. Then full blown disease occurs causing meningitis, nephritis, hepatitis, rash.
Rickettsia Rickettsii causes
Rocky Mountain Spotted Fever
Rickettsia Rickettsii gram stain?
None.
Reservoir?
Hard ticks, also the vector
Why is it so important?
23% mortality
How is R. rickettsii pathogenic?
Obligate intracellular organism
Where does R. rickettsii occur?
Southeast
What are the symptoms of rocky mountain spotted fever?
Fever, headache, spotted rash.
How does R. rickettsii enter the cell?
At endothelial cell! Induces its own phagocytosis, releases phospholipase to escape from the phagosome and propels itself by using host cell actin.
Ehrlichiosis caused by?
Ehrlichia chaffeensis
What happens in ehrlichiosis?
Monocytes are invaded
What causes anaplasmosis?
Anaplasma phagocytophilium
What happens in anaplasmosis?
Granulocytes invaded.
Where do ehrlichiosis and anaplasmosis occur?
E: Southeast
A: Northeast
How to treat rickettsia, ehrlichiosis, and anaplasmosis?
Immediate doxycycline.
