Arthropodborne bacterial Flashcards
CA - plague
Yersinia pestis
- gram negative bacillus
Reservoir - plague
1- rats, wild rodents
2- human
Arthropod vector - plague
Rat flea
Mode of transmission - plague
Pathogen in rat —> spread to rat flea —> human becomes diseased
Bubonic plague - plague
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
Septicemic plague
Septic shock due to bacteremia
Pneumonic plague
Airborne/droplet transmission
- bacteremia —> lungs
- near 100% mortality rate if left untreated
Diagnosis - plague
Serology, sputum sample from lung, fluid aspiration from buboes
Predisposing factors - plague
Poor sanitation (rats)
Prevention - plague
- eliminate the reservoir
- plague vaccine for high risk people; only for bubonic plague
Treatment - plague
High dose antibiotics
Misc - plague
Endemic to parts of the U.S.
CA - Lyme disease
Borrelia burgdorferi
- spiral-shaped bacterium, SPIROCHETE, motile
Reservoir - Lyme disease
1- field/deer mice
2- deer
Arthropod vector - Lyme disease
Tick
Transmission - Lyme
Pathogen in mouse/deer —> spreads to mouse/deer tick —> human becomes diseased
Misc - Lyme
- high incidence during summer
- most common tick borne disease in the US
Sxs - Lyme
First phase
- bulls-eye rash
Second phase
- flu-like sxs, irregular heartbeat, encephalitis, facial paralysis
Third phase
- arthritis due to an immune response
Diagnosis - Lyme
Based clinical sxs, prevalence in geographic area, serology
Prevention - Lyme
Wear protective clothing, tick repellant, avoid rodents & deer
Treatment - Lyme
Antibiotics (only for early stages)
CA - epidemic typhus & Rocky Mountain spotted fever
Genus Rickettsia
- gram negative bacillus or COCCOBACILLUS
- obligate intracellular parasite
- characteristic spotted rash on body (flat rash)
Epidemic typhus AKA
Typhus fever
CA - Epidemic typhus
Rickettsia prowazekii
- gram negative bacillus or COCCOBACILLUS, obligate intracellular parasite
Reservoir - epidemic typhus
Human body louse (lice)
Arthropod vector? - epidemic typhus
Louse
How? - epidemic typhus
Pathogen in body louse —> spread to human & becomes diseased
Transmission - epidemic typhus
Transmitted when louse feces (has pathogen) is rubbed into the bite wound from the louse
Sxs - epidemic typhus
Prolonged high fever followed by spotted red rash (due to subcutaneous hemorrhaging)
- spotted rash: chest/trunk —> extremities
Diagnosis - epidemic typhus
By type of rash (spotted, red, flat) and location, serology
Pre-disposing factors - epidemic typhus
Wars, homelessness, crowded jails, concentration camps
Prevention - epidemic typhus
Good personal hygiene
Treatment - epidemic typhus
Antibiotics
Misc - epidemic typhus
High mortality rate if left untreated
CA - Rocky Mountain spotted fever
Rickettsia rickettsii
- gram negative bacillus or COCCOBACILLUS, obligate intracellular parasite
Reservoir - Rocky Mountain spotted fever
Tick
Arthropod vector - Rocky Mountain spotted fever
Tick
Transmission - Rocky Mountain spotted fever
Pathogen in tick —> spread to human & becomes diseased
How is bacteria transmitted by? - Rocky Mountain spotted fever
Transovarian passage
- new larvae are already infected upon hatching from eggs
Which developmental stage is responsible for Rocky Mountain spotted fever?
Infected nymph
Sxs - Rocky Mountain spotted fever
Fever followed by spotted red rash due to subcutaneous hemorrhaging
- spotted rash: extremeties (palms & soles) —> chest/trunk
Diagnosis - Rocky Mountain spotted fever
By type of rash & location, serology
Predisposing factors - RMSF
Outdoors , hiking
Prevention - RMSF
Protective clothing, tick repellant
Treatment - RMSF
Antibiotics
What region is most common for this disease - RMSF
Most common in southeast & Appalachian mountains region
