Zoonotic Infections

Question 1

Bartonella henselae, stain/appearance, transmission, CM

Answer 1

Cat scratch dz
Gram neg bacillus (aerobe)
Cat scratches
Papule or lesion at affected site and persists for a few weeks…fever, headache, malaise, and lymphadenopathy develop 2-3 weeks after…lipid A endotoxin triggers inflammation

Question 2

Pasteruella multicoda…staining, transmission, CM

Answer 2

Gram neg bipolar staining facultative
Dog or cat bite/scratch (cat worse)
Pain and swelling at puncture site, localized lymphangitis
Can lead to septic arthritis and osteomyelitis

Question 3

Borrelia burgdorfi…structure, note, 3 phases of CM

Answer 3

Spirochete (use darkfield microscopy)
May not remember being bitten
1) Circular lesion with clear center (erthema migrans) accompanied by flulike symptoms…spreads via blood and lymph to MSK sites, skin, CNS, heart
2) weeks to months, arthritis, arthralgia, cardiac complications, meningitis
3) Chronic arthritis, progressive CNS dz, cardiac dysfunction

Question 4

B burgdorfi virulence

Answer 4

Does very little to stimulate host response
No LPS
Abundant outer surface proteins but the immune stimulatory portions are buried in the outer membrane
Flagella in the periplasmic space

Question 5

RMSF structure and where it infects

Answer 5

Gram neg pleomorph - Rickettsia rickettsii
Obligate intracell
Tropism for vascular endothelium
Mid atlantic and southeast regions

Question 6

RMSF pathophys

Answer 6

Vascular lesions caused by replication in vascular endothelial cells…focal areas or endotheliala prolif and perivascular infiltraation leading to thrombosis and leakacge of RBCs into surrounding tissues

Question 7

RMSF CM

Answer 7

Fever, headaches, rash starts on wrists and ankles and moves to palms and soles

Question 8

Francisella tulerensis, structure, how it is transmitted, what it causes, pathophys

Answer 8

Gram neg coccobacillia (Rabbit Fever)
Contaminated meat, animals, aerosols, vectors
Ulceroglandular tularemia - fever with ulcerative lesion and regional lymphandeopathy
Can cause penumonic tularemia
Reaches regional lymph node after escaping phagosome

Question 9

Yersinia pestis structure, what it causes, trasmission

Answer 9

Gram neg rod (looks like safety pin)
Black death
Dz of rodents trasmitted by fleas

Question 10

CM of yersinia pestis

Answer 10

Intense hemorrhagic inflammation develops in enlarged lymph nodes (buboes)…may undergo necoriss

Question 11

Chikungunya

Answer 11

ssRNA+ env

Acute onset fever with polyarthralgia (bilateral and severe)

Question 12

Zika

Answer 12

ssRNA+ env

Low grade fever with maculopapular rash, arthralgia (especially in joints of hands and feet), conjunctivitis

Question 13

Dengue

Answer 13

ssRNA+ env

Marked muscle and joint pain (Break bone fever), and rash

Question 14

Yellow fever

Answer 14

ssRNA+ env

1) Fever, headache, joint pain
2) Abatement of symptoms
3) Return of fever, nausea, jaundice

Question 15

West Nile

Answer 15

ssRNA+ env

Fever, headache, body aches that become neuro deficitis (encephalitis)

Question 16

Pathogen of zoonotic viruses

Answer 16

Virus injected into cap ciruclation…virus comes into contact with target cells…replicates…secondary viremia breaks out and leads to infection of organs

Question 17

Where does CHIKV replicate

Answer 17

In fibroblasts in the skin and then spreads

Question 18

DENV with Heamorrhagic fever

Answer 18

hemorrhagic will start to affet vascular systems, bleed a ton and use up all platelets (purple fever)

Question 19

West nile pathogen

Answer 19

Begins in keratinocytes and immune cells in epidermis and spreads to lymph nodes…moves from lymph nodes to peripheral organs