WBR0464
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Microbiology |
| Sub Category | SubCategory::General Principles, SubCategory::Infectious Disease |
| Prompt | [[Prompt::The plague epizootic is a severe infectious disease characterized by high mortality. It is due to a bacterial infection that cycles between flea and, wild rodents, squirrels, prairie dogs or cats. What is the bacterial organism that causes the plague?]] |
| Answer A | AnswerA::Francisella tularensis |
| Answer A Explanation | AnswerAExp::Francisella tularensis is the organism that causes tularemia. |
| Answer B | AnswerB::Ehrlichiosis chaffeensis |
| Answer B Explanation | AnswerBExp::Ehrlichiosis chaffeensis is the organism that causes ehrlichiosis. |
| Answer C | AnswerC::Yersinia pestis |
| Answer C Explanation | AnswerCExp::Yersinia pestis is the organism that causes the plague. |
| Answer D | AnswerD::Chlamydophila psittaci |
| Answer D Explanation | AnswerDExp::Chlamydophila psittaci is the organism that causes psittacosis. |
| Answer E | AnswerE::Borrelia recurrentis |
| Answer E Explanation | AnswerEExp::Borrelia recurrentis is the organism that causes recurrent fever. |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The plague epizootic is a high-mortality infectious disease that is due to an infection by Yersinia pestis, a gram negative bacterium. The organism;s natural reservoir includes flea, wild rodents, squirrels, prairie dogs, and cats. Transmission of the disease requires a bite by any of the abovementioned natural reservoirs. Although the plague is caused by only one organism, manifestations of the plague can be different.
Bubonic plague: Most common form that manifests are large tender lymphadenopathy. Pneumonic plague: Most severe forms that infects the lungs. Septicemic plague: Rarest form that causes bacteremia and disseminated intravascular coagulation (DIC). In USA, the plaque is extremely rare. Less than 20 cases are reported each year, mostly in Southwest USA. Educational Objective: The plague is caused by the gram negative bacterium Yersinia pestis. It is transmitted by flea bite, or bite of wild rodents or squirrels, or other animals like prairie dogs and cats. There are 3 types of plague: Bubonic, pneumonic, and septicemic. Reference:
Perry RD, Fetherson JD. Yersinia pestis – etiologic agent of plague. Clin Micriobiol Rev. 1997;10(1):35-66 |
| Approved | Approved::No |
| Keyword | WBRKeyword::Yersinia, WBRKeyword::pestis, WBRKeyword::plague, WBRKeyword::rodent, WBRKeyword::prairie, WBRKeyword::dog, WBRKeyword::prairie dog, WBRKeyword::cat, WBRKeyword::yersinia pestis |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |