A farmer from central asia persents with an acute onsetr of swinging pyrexia, rigor sweating and monoartucular arthritis of the hip. He also complained of headache and insommia On examination he is found to have a small firm splenomegaly and hepatomegaly. His counts showed leucopenia with relative lymphocytosis The most likely diagnosis is –
**Core Concept**
The patient's presentation is suggestive of a systemic infection, likely caused by an intracellular pathogen, which has led to a chronic inflammatory response. This condition is characterized by fever, arthritis, and organomegaly, with a notable decrease in white blood cell count and an increase in lymphocytes.
**Why the Correct Answer is Right**
The patient's symptoms are indicative of Brucellosis, a zoonotic infection caused by Brucella species, which are typically acquired through contact with infected animals or their products. The presentation of swinging pyrexia, rigor, sweating, and monoarticular arthritis, along with hepatosplenomegaly and leucopenia with relative lymphocytosis, is classic for Brucellosis. The infection is thought to occur when Brucella bacteria are ingested through the gastrointestinal tract, leading to an intracellular infection that triggers a chronic inflammatory response.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not match the patient's presentation. The symptoms described are not typical of Tuberculosis, which usually presents with chronic cough, weight loss, and night sweats.
**Option B:** This option is incorrect because it is not consistent with the patient's laboratory findings. The patient's leucopenia with relative lymphocytosis is not typical of Typhoid fever, which usually presents with leucocytosis.
**Option C:** This option is incorrect because it does not account for the patient's symptoms and laboratory findings. The patient's presentation is not typical of Rheumatoid Arthritis, which usually presents with polyarticular joint involvement and systemic symptoms.
**Option D:** This option is incorrect because it does not match the patient's geographical location. The patient is from Central Asia, where Brucellosis is more common than in other parts of the world.
**Clinical Pearl / High-Yield Fact**
Brucellosis is a zoonotic infection that can be prevented through proper handling and cooking of animal products, as well as vaccination of livestock. Healthcare workers should be aware of the risk of transmission through contact with infected animals or their products.
**Correct Answer:** D.