Final answer:
In an HIV-positive patient, multiple ring-enhancing lesions on a CT scan are indicative of opportunistic infections such as toxoplasmosis. Treatment includes specific antimicrobials and optimizing antiretroviral therapy to improve immune function and prevent further infections.
Step-by-step explanation:
An HIV-positive patient with multiple ring-enhancing lesions on a CT scan likely signifies the presence of an opportunistic infection such as toxoplasmosis, which is common in patients with a weakened immune system. The standard treatment for cerebral toxoplasmosis includes a combination of antimicrobials such as pyrimethamine, sulfadiazine, and folinic acid to prevent hematologic toxicity. It is also essential to initiate or optimize antiretroviral therapy (ART) to strengthen the immune system and prevent further opportunistic infections.
The presence of these lesions underscores the importance of early detection and treatment of HIV to slow disease progression. Utilization of sensitive tests like flow cytometry to monitor CD4 T-cell counts can inform treatment strategies. If counts fall below 500 cells/μL, it suggests a severe impairment of the immune system, making the patient more susceptible to opportunistic infections, thereby necessitating adjustment in the treatment regimen.