Cerebral Microsporidiosis Due to Encephalitozoon cuniculi in a Patient with Human Immunodeficiency Virus Infection

Microsporidia are obligate, intracellular, spore-forming protozoa that are parasitic in every major animal group. 1 Cerebral microsporidial infection was first described in 1922 in rabbits with granulomatous encephalitis, 2 and the organism was named Encephalitozoon cuniculi. 3 In 1959 and 1984, two cases of infection in children with seizure disorders were attributed to E. cuniculi. 4 , 5 The diagnosis was based on light-microscopical detection of microsporidial spores in cerebrospinal fluid and urine samples, but the identification of the species remained inconclusive, because immunologic and molecular techniques to distinguish among encephalitozoon-like microsporidia were not available at that time. In recent years, three distinct encephalitozoon species . . .