Brain abscess in AIDS Coloured computed tomography CT scan of an axial section through the brain of an AIDS patient showing cerebral abscess At top left is the lesion yellow of the abscess with affected and discoloured brain tissue near it At centre are dark ventricles of the brain folds of the cerebrum are seen on the edge of the brain An abscess is a collection of pus due to infection In AIDS Acquired immune deficiency syndrome infections result from the lowered immunity of the patient Cerebral abscess in AIDS patients may be due to infection by bacteria or toxoplasma