Arthropodborne bacterial

Question 1

CA - plague

Answer 1

Yersinia pestis
- gram negative bacillus

Question 2

Reservoir - plague

Answer 2

1- rats, wild rodents
2- human

Question 3

Arthropod vector - plague

Answer 3

Rat flea

Question 4

Mode of transmission - plague

Answer 4

Pathogen in rat —> spread to rat flea —> human becomes diseased

Question 5

Bubonic plague - plague

Answer 5

Yersinia pestis grows in phagocytes —> bacteremia —> lymph nodes
- hard and swollen lymph nodes in axilla and groin =buboes
- fever, chills, body ache, bleeding into the skin (which turns black)
- most common plague, 50-75% mortality rate

Question 6

Septicemic plague

Answer 6

Septic shock due to bacteremia

Question 7

Pneumonic plague

Answer 7

Airborne/droplet transmission
- bacteremia —> lungs
- near 100% mortality rate if left untreated

Question 8

Diagnosis - plague

Answer 8

Serology, sputum sample from lung, fluid aspiration from buboes

Question 9

Predisposing factors - plague

Answer 9

Poor sanitation (rats)

Question 10

Prevention - plague

Answer 10

• eliminate the reservoir
• plague vaccine for high risk people; only for bubonic plague

Question 11

Treatment - plague

Answer 11

High dose antibiotics

Question 12

Misc - plague

Answer 12

Endemic to parts of the U.S.

Question 13

CA - Lyme disease

Answer 13

Borrelia burgdorferi
- spiral-shaped bacterium, SPIROCHETE, motile

Question 14

Reservoir - Lyme disease

Answer 14

1- field/deer mice
2- deer

Question 15

Arthropod vector - Lyme disease

Answer 15

Tick

Question 16

Transmission - Lyme

Answer 16

Pathogen in mouse/deer —> spreads to mouse/deer tick —> human becomes diseased

Question 17

Misc - Lyme

Answer 17

• high incidence during summer
• most common tick borne disease in the US

Question 18

Sxs - Lyme

Answer 18

First phase
- bulls-eye rash
Second phase
- flu-like sxs, irregular heartbeat, encephalitis, facial paralysis
Third phase
- arthritis due to an immune response

Question 19

Diagnosis - Lyme

Answer 19

Based clinical sxs, prevalence in geographic area, serology

Question 20

Prevention - Lyme

Answer 20

Wear protective clothing, tick repellant, avoid rodents & deer

Question 21

Treatment - Lyme

Answer 21

Antibiotics (only for early stages)

Question 22

CA - epidemic typhus & Rocky Mountain spotted fever

Answer 22

Genus Rickettsia
- gram negative bacillus or COCCOBACILLUS
- obligate intracellular parasite
- characteristic spotted rash on body (flat rash)

Question 23

Epidemic typhus AKA

Answer 23

Typhus fever

Question 24

CA - Epidemic typhus

Answer 24

Rickettsia prowazekii
- gram negative bacillus or COCCOBACILLUS, obligate intracellular parasite

Question 25

Reservoir - epidemic typhus

Answer 25

Human body louse (lice)

Question 26

Arthropod vector? - epidemic typhus

Answer 26

Louse

Question 27

How? - epidemic typhus

Answer 27

Pathogen in body louse —> spread to human & becomes diseased

Question 28

Transmission - epidemic typhus

Answer 28

Transmitted when louse feces (has pathogen) is rubbed into the bite wound from the louse

Question 29

Sxs - epidemic typhus

Answer 29

Prolonged high fever followed by spotted red rash (due to subcutaneous hemorrhaging) - spotted rash: chest/trunk —> extremities

Question 30

Diagnosis - epidemic typhus

Answer 30

By type of rash (spotted, red, flat) and location, serology

Question 31

Pre-disposing factors - epidemic typhus

Answer 31

Wars, homelessness, crowded jails, concentration camps

Question 32

Prevention - epidemic typhus

Answer 32

Good personal hygiene

Question 33

Treatment - epidemic typhus

Answer 33

Antibiotics

Question 34

Misc - epidemic typhus

Answer 34

High mortality rate if left untreated

Question 35

CA - Rocky Mountain spotted fever

Answer 35

Rickettsia rickettsii - gram negative bacillus or COCCOBACILLUS, obligate intracellular parasite

Question 36

Reservoir - Rocky Mountain spotted fever

Answer 36

Tick

Question 37

Arthropod vector - Rocky Mountain spotted fever

Answer 37

Tick

Question 38

Transmission - Rocky Mountain spotted fever

Answer 38

Pathogen in tick —> spread to human & becomes diseased

Question 39

How is bacteria transmitted by? - Rocky Mountain spotted fever

Answer 39

Transovarian passage - new larvae are already infected upon hatching from eggs

Question 40

Which developmental stage is responsible for Rocky Mountain spotted fever?

Answer 40

Infected nymph

Question 41

Sxs - Rocky Mountain spotted fever

Answer 41

Fever followed by spotted red rash due to subcutaneous hemorrhaging - spotted rash: extremeties (palms & soles) —> chest/trunk

Question 42

Diagnosis - Rocky Mountain spotted fever

Answer 42

By type of rash & location, serology

Question 43

Predisposing factors - RMSF

Answer 43

Outdoors , hiking

Question 44

Prevention - RMSF

Answer 44

Protective clothing, tick repellant

Question 45

Treatment - RMSF

Answer 45

Antibiotics

Question 46

What region is most common for this disease - RMSF

Answer 46

Most common in southeast & Appalachian mountains region