DISSEMINATED MICROSPORIDIOSIS ESPECIALLY INFECTING THE BRAIN, HEART, AND KIDNEYS - REPORT OF A NEWLY RECOGNIZED PANSPOROBLASTIC SPECIES IN 2 SYMPTOMATIC AIDS PATIENTS

Microsporidia have emerged as important opportunistic AIDS pathogens o f the alimentary, respiratory, and urinary tracts. Although non-human mammalian microsporidia infections typically include encephalitis, CNS microsporidiosis has not been reported in patients with AIDS, A 33-ye ar-old white male and an 8-year-old black girl presented with seizures and declining mental status. Central nervous system (CNS) imaging stu dies revealed small peripherally and diffusely enhancing lesions prese nt for at least 2 and 4 months before death, respectively. Both patien ts expired despite empirical anti-toxoplasma therapy. Their brains con tained innumerable soft gray matter lesions that consisted of central areas of necrosis, filled with free spores and spore-laden macrophages , surrounded by microsporidia-infected astrocytes. The complete autops y of the child also revealed necrotizing and sclerosing cardiac and re nal microsporidiosis and infection of the pancreas, thyroid, parathyro ids, liver, spleen, lymph nodes, and bone marrow, Infected cells inclu ded astrocytes, cardiac myocytes, epithelium, endothelium, vascular sm ooth muscle cells, hepatocytes, adipocytes, Schwann cells, and macroph ages. Light and electron microscopic studies revealed pansporoblastic development within thick-walled sporophorous vacuoles of parasite orig in. Although most similar to Pleistophora sp and Thelohania sp, this m icrosporidian is different from any known species. Microsporidiosis sh ould be considered as the possible cause of a wide range of diseases i n AIDS patients, including CNS, cardiac, and renal.