Malta fever is caused by:
**Core Concept**
Malta fever, also known as brucellosis, is a zoonotic infection caused by bacteria of the genus Brucella. It is primarily transmitted through contact with infected animals, especially those that produce and consume unpasteurized dairy products.
**Why the Correct Answer is Right**
The correct answer is Brucella melitensis, which is one of the most common causes of Malta fever. This bacterium is typically found in goats, sheep, and other small ruminants. Infection occurs when humans ingest contaminated milk, cheese, or other dairy products. Brucella melitensis then enters the body through the gastrointestinal tract and disseminates to various organs, including the liver, spleen, and lymph nodes. The bacteria can also be transmitted through direct contact with infected animals or their tissues.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a known cause of Malta fever. While other pathogens can cause similar symptoms, Brucella melitensis is the primary agent responsible for this disease.
**Option B:** This option is incorrect because it is a different genus of bacteria altogether. While some bacteria in this genus can cause disease in humans, they are not associated with Malta fever.
**Option C:** This option is incorrect because it is a different species of Brucella, which is primarily found in cattle. While Brucella abortus can cause disease in humans, it is not as commonly associated with Malta fever as Brucella melitensis.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that Brucella melitensis is highly contagious and can be transmitted through contact with infected animals or their products. Healthcare workers should take proper precautions when handling patients with suspected Malta fever, including wearing personal protective equipment and following strict infection control measures.
**Correct Answer:** D.