An HIV patient complains of visual disturbances. Examination of fundus of the eye bilateral retinal exudates and perivascular haemorrhages. Which of the following virus is the most likely causative agent?
**Core Concept**
Retinal exudates and perivascular hemorrhages in an HIV patient suggest a viral infection that affects the retina, leading to inflammation and damage. The most likely causative agent is a virus that replicates in the retinal cells, causing immune-mediated damage.
**Why the Correct Answer is Right**
The correct answer is **Cytomegalovirus (CMV)**. CMV is a member of the herpesvirus family and is a common opportunistic pathogen in HIV-infected individuals. CMV retinitis occurs when CMV infects the retinal cells, leading to inflammation and damage. This results in retinal exudates and perivascular hemorrhages, as seen in the patient's examination. CMV retinitis is a classic example of an opportunistic infection in HIV/AIDS patients, which can lead to vision loss if left untreated.
**Why Each Wrong Option is Incorrect**
* **Option A:** Herpes simplex virus (HSV) is a common cause of ocular infections, but it typically causes keratitis or uveitis rather than retinitis in HIV patients.
* **Option B:** Varicella-zoster virus (VZV) can cause ocular complications in HIV patients, but it typically causes retinitis in immunocompromised individuals, particularly those with CD4 counts < 100 cells/μL.
* **Option D:** Epstein-Barr virus (EBV) is a common cause of infectious mononucleosis and is associated with various malignancies, but it is not typically associated with retinitis in HIV patients.
**Clinical Pearl / High-Yield Fact**
CMV retinitis is a medical emergency in HIV/AIDS patients, as it can lead to rapid vision loss if left untreated. Early diagnosis and treatment with antiviral medications, such as ganciclovir, can prevent vision loss and improve outcomes.
**Correct Answer:** C. Cytomegalovirus (CMV)