Zoonotic and Vector-borne Bacterial Infections II Flashcards
Borrelia: Gram stain Shape Aerobic ability Diseases caused (2)
- Neither gram positive nor negative
- Long Spirochete
- Microaerophilic
- Causes Lyme disease and Relapsing Fever
What species of borrelia causes Lyme Disease in U.S.?
Borrelia burgdoferi
What is major vector for Lyme Disease?
Lxodes spp. of ticks
Stages of Lyme Disease (3)
Early stage 1 develops rapidly- localized infection
Stage 2- Disseminated infection
Chronic stage 3 develops 2-3 years after primary infection (persistent infection)
Early infection, stage 1 of Lyme disease:
Lesion
Symptoms (6)
Bulls-eye rash
Malaise, fever, HA, fatigue, myalgia, and lymphadenopathy
Stage 2 Lyme Disease symptoms and timing
- Begins 3-5 weeks after bite
2. Arthralgia, myalgia, cardiac dysfunction, CNS symptoms, meningitis, and encephalitis
Late, Stage 3 Lyme Disease
Symptoms
- One or more joints affected with arthritis
- Skin discoloration and swelling
- Neurological complaints
Lyme disease diagnosis
Diagnosis is based on symptoms, physical findings, and history.
Serology and culture are of limited use
Lyme disease treatment (DAC)
- Early stages
- Late Stage
- Early: doxycycline, amoxicillin, or cefuroxime
2. Late: doxycycline, amoxicillin, or ceftriaxone
Relapsing Fever:
Gram stain
Shape
Types (2) and cause of that type
- Poor staining, gram negative
- Spirochetes
- Epidemic Type (louse borne)
Endemic Type (tick borne)
How does relapsing fever evade the immune system?
Antigenic variation
Epidemiology:
Endemic relapsing fever
Epidemic relapsing fever
Endemic is tick borne, zoonotic, and prevalent in Africa
Epidemic is NOT zoonotic and is transmitted from human to human via louse. Restricted to North Africa and South America
Relapsing fever clinical progression and presentation
Presents as flu-like, possibly with splenomegaly and hepatomegaly.
Symptoms last 3-7 days, resolve, and return after 7 days due to antigenic variation
Relapsing Fever diagnosis and treatment
Diagnosis: microscopy, culture, and/or serology
Treatment: tetracycline or erythromycin
Rickettsia:
Gram stain
Shape
Cellular location
Very small gram negative coccobacilli (difficult to stain)
Obligate intracellular pathogens
Rickettisa manifestations
Skin
Systemic
Skin- inflammation, thrombosis, rash, petechial lesion
Systemic- vascular lesions throughout the body
Rocky Mountain Spotted Fever
Causative agent
Vectored by (2)
Rickettsia rickettsii
Dog tick (east of rocky mountains and pacific coast)
Rocky Mountain Wood Tick (rockies)
When do most cases of RMSF occur?
Where do most cases of RMSF occur?
> 90% of cases reported between April and September
>50% in South Atlantic
RMSF presentation:
Initially presents with fever then 2-5 days later, rash shows up and it is ready to party
Untreated RMSF symptoms (6)
DIC, thrombocytopenia, pulmonary edema, renal failure, GI hemorrhage, and shock
So hell basically…an actual real hell
RMSF Diagnosis (2)
Clinical presentation and hx
Serology
RMSF treatment
Doxycycline is the drug of choice…boom…micro’ed
Ehrlichiosis
Gram stain
Shape
Cellular location
Small, gram negative intracellular pathogens that parasitize monocytes and granulocytes
Ehrlichiosis:
Replicate and form colonies within vacuoles known as…
MORULAE
