Which of the following is the causative agent of Malta fever?
Malta fever is caused by a specific pathogen. The options are probably bacteria like Brucella species, Coxiella burnetii, or maybe something else. Wait, Coxiella burnetii causes Q fever. So if the question is about Malta fever, then the answer might be Brucella. But I need to confirm.
Brucellosis is associated with consuming unpasteurized dairy products or contact with infected animals. The symptoms include fever, sweating, and joint pain. The name "Malta fever" comes from its historical association with the Mediterranean region, including Malta. So the causative agent is Brucella species. Which one specifically? Brucella melitensis is common in the Mediterranean, so that's likely the answer.
The options probably list Brucella melitensis as an option. The other options might include Coxiella burnetii (Q fever), Yersinia pestis (plague), or others. Let me check: Q fever is from Coxiella, brucellosis from Brucella, and Malta fever is another name for brucellosis. So the correct answer is Brucella melitensis.
Now, the incorrect options: Option A might be something like Rickettsia, which causes typhus. Option B could be Coxiella for Q fever. Option C maybe Salmonella. Option D perhaps Yersinia. Each of these is incorrect because they cause different diseases. So the explanation should clarify why each is wrong.
**Core Concept** Malta fever, also known as Mediterranean fever or undulant fever, is a bacterial zoonosis caused by *Brucella* species. It is transmitted to humans via consumption of unpasteurized dairy products or contact with infected animals, particularly goats, sheep, and cattle.
**Why the Correct Answer is Right** The causative agent is *Brucella melitensis*, which is the most virulent species among Brucella for humans. It enters the body through mucous membranes or skin abrasions, leading to systemic infection characterized by fever, sweating, and joint pain. The organism survives within macrophages by inhibiting phagosome-lysosome fusion, evading the host immune response.
**Why Each Wrong Option is Incorrect**
**Option A:** *Coxiella burnetii* causes Q fever, not Malta fever.
**Option B:** *Yersinia pestis* causes plague, unrelated to brucellosis.
**Option C:** *Rickettsia rickettsii* causes Rocky Mountain spotted fever.
**Option D:** *Salmonella typhi* causes typhoid fever, not brucellosis.
**Clinical Pearl / High-Yield Fact** Remember that *Brucella melitensis* is the most common cause of brucellosis in the Mediterranean region (hence "Malta fever"). Diagnosis relies on serology (e.g., Rose Bengal test) and blood cultures. Treatment typically involves doxycycline plus rifampin or streptomycin.