Central Nervous System Infections in HIV Patients

Abstract

Acquired immune deficiency syndrome (AIDS) occurs from human immunodeficiency virus (HIV) infection. Despite the accessibility of highly active antiretroviral therapy (HAART) since 1995 and the use of prophylactic antimicrobial regimens, opportunistic infections continue to have a devastating effect on HIV-infected patients, especially those diagnosed late or inadequately treated. About 1–10 per 1,000 patient–years has CNS opportunistic infections, and less than 5% of patients with AIDS have a normal brain on autopsy. Opportunistic microorganisms are less virulent under normal conditions (immunocompetent hosts), but individuals with immune dysfunction are more susceptible to mycobacterial, viral, fungal, and some parasitic infections. Neuroinfections can occur at any stage and may even precede the diagnosis of HIV infection. Clinically, CNS infections reflect intraparenchymal and leptomeningeal involvement, but clinical signs and symptoms may be blurred owing to alterations of host responses to pathogens, so it is important to preserve a broad perspective in the HIV population. Treatment of these neuroinfections is mainly medical, but neurosurgical consultation is often requested for diagnostic purposes (surgical biopsy), CSF shunting, and surgical resection of some lesions. Difficult-to-treat microorganisms and polymicrobial infections seen in HIV patients are associated with an increased relapse rate, as are a suboptimal choice of antibiotherapy or insufficient duration of treatment. As with other CNS and spinal infectious diseases, early diagnosis and effective management will reduce morbidity and mortality and will improve the patient’s overall quality of life.