Which condition is characterized as an AIDS-defining illness in patients with a CD4 count less than 100?

Which condition is characterized as an AIDS-defining illness in patients with a CD4 count less than 100?

• A. Cerebral toxoplasmosis
• B. Pneumocystis pneumonia
• C. Kaposi's sarcoma
• D. Cytomegalovirus infection

Answer: (A)

Cerebral toxoplasmosis is indeed recognized as an AIDS-defining illness, particularly in patients with a CD4 count below 100 cells/mm³. This condition is associated with infection by the Toxoplasma gondii parasite and typically presents in immunocompromised individuals, such as those with advanced HIV/AIDS. The low CD4 count signifies a weakened immune response, making these patients highly susceptible to opportunistic infections, including cerebral toxoplasmosis. Clinical manifestations often include neurological symptoms such as headaches, seizures, and focal neurological deficits, resulting from the formation of small abscesses in the brain. The diagnosis is commonly confirmed via imaging studies like CT or MRI, which may reveal characteristic ring-enhancing lesions, and serological testing for Toxoplasma antibodies can further support the diagnosis. While other conditions listed are also associated with advanced HIV disease, cerebral toxoplasmosis is specifically noted for its occurrence in individuals with severely compromised immune systems, particularly those with CD4 counts falling below the critical threshold of 100, distinguishing it as an important AIDS-defining illness in this context.

Cerebral toxoplasmosis is indeed recognized as an AIDS-defining illness, particularly in patients with a CD4 count below 100 cells/mm³. This condition is associated with infection by the Toxoplasma gondii parasite and typically presents in immunocompromised individuals, such as those with advanced HIV/AIDS. The low CD4 count signifies a weakened immune response, making these patients highly susceptible to opportunistic infections, including cerebral toxoplasmosis.

Clinical manifestations often include neurological symptoms such as headaches, seizures, and focal neurological deficits, resulting from the formation of small abscesses in the brain. The diagnosis is commonly confirmed via imaging studies like CT or MRI, which may reveal characteristic ring-enhancing lesions, and serological testing for Toxoplasma antibodies can further support the diagnosis.

While other conditions listed are also associated with advanced HIV disease, cerebral toxoplasmosis is specifically noted for its occurrence in individuals with severely compromised immune systems, particularly those with CD4 counts falling below the critical threshold of 100, distinguishing it as an important AIDS-defining illness in this context.