Bartonella henselae causes all except –
**Core Concept**
Bartonella henselae is a gram-negative bacterium that causes a range of infections, primarily transmitted through cat scratch or flea bites. This bacterium is known to cause several diseases, including cat scratch disease (CSD), bacillary angiomatosis, and trench fever.
**Why the Correct Answer is Right**
Cat scratch disease (CSD) is the most common manifestation of Bartonella henselae infection, typically presenting with regional lymphadenopathy, fever, and swelling at the site of the scratch. The bacterium invades the lymph nodes, causing granulomatous inflammation and eventually leading to the formation of a painful, swollen lymph node, known as a cat scratch lymph node. This is a result of the bacterium's ability to evade the host's immune system and survive within the macrophages and endothelial cells of the lymph node.
**Why Each Wrong Option is Incorrect**
**Option A:**
Bartonella henselae is indeed associated with cat scratch disease, which is characterized by lymphadenopathy and fever. Therefore, this option is incorrect as it is a manifestation of B. henselae infection.
**Option B:**
Bartonella quintana, not B. henselae, is the causative agent of trench fever. Trench fever is a vector-borne disease transmitted by the human body louse and characterized by fever, headache, and muscle pain.
**Option C:**
Bartonella henselae is also associated with bacillary angiomatosis, a condition characterized by the formation of vascular lesions in immunocompromised patients. This option is correct, so it will be skipped in the explanations for incorrect options.
**Option D:**
Bartonella henselae is not known to cause endocarditis, which is typically associated with other pathogens such as Staphylococcus aureus, Streptococcus viridans, and HACEK group bacteria. Therefore, this option is incorrect.
**Clinical Pearl / High-Yield Fact**
Bartonella henselae infection can be diagnosed through serological tests, such as indirect immunofluorescence or enzyme-linked immunosorbent assay (ELISA), and PCR. It's essential to consider B. henselae in patients with unexplained lymphadenopathy or fever, especially in those with a history of cat exposure.
**Correct Answer: D. Bartonella henselae does not cause endocarditis.**