Diseases Transmitted by Arthropod Vectors

Question 1

Plague

Answer 1

Yersenia pestis
G(-) coccobacilli
- zoonosis; spread from infected rodents (prairie dogs in W. Texas)
2 forms:
1. Bubonic - w/in a week of being bitten - sudden headache, fever, weakness; “bubo” (swollen, painful lymph nodes). If gets into bloodstream, can cause septicemia. “black death” = subcutaneous hemorrhage. Can turn into Pneumonic Plague
2. Pneumonic plague - if bacteremia occur & bacteria travel to lungs, then becomes communicable via respiratory droplet. Shorter IP & higher mortality (90%) rate. Cough w/bloody sputum.
- Ring around the Rosy….”
- treat w/cipro, streptomycin

Question 2

Brill Zinsser

Answer 2

Rickettsia prowazekii

• recurrence of epidemic typhus
• disease has milder symptoms, shorter in duration, often does not cause skin rash
• caused by reactivation of latent microorganisms harbored in lymph nodes