CHAGASIC MENINGOENCEPHALITIS IN AN HIV INFECTED PATIENT WITH MODERATE IMMUNOSUPPRESSION: PROLONGED SURVIVAL AND CHALLENGES IN THE HAART ERA / Meningoencefalite chagásica em paciente infectada pelo HIV com imunodepressão moderada: desafios na era HAART e sobrevida prolongada

The reactivation of Chagas disease in HIV infected patients presents high mortality and morbidity. We present the case of a female patient with confirmed Chagasic meningoencephalitis as AIDS-defining illness. Interestingly, her TCD4+ lymphocyte cell count was 318 cells/mm3. After two months of induction therapy, one year of maintenance with benznidazol, and early introduction of highly active antiretroviral therapy (HAART), the patient had good clinical, parasitological and radiological evolution. We used a qualitative polymerase chain reaction for the monitoring of T. cruzi parasitemia during and after the treatment. We emphasize the potential value of molecular techniques along with clinical and radiological parameters in the follow-up of patients with Chagas disease and HIV infection. Early introduction of HAART, prolonged induction and maintenance of antiparasitic therapy, and its discontinuation are feasible, in the current management of reactivation of Chagas disease.

A reativação da doença de Chagas em pacientes com a infecção pelo HIV apresenta uma alta morbidade e mortalidade. Neste relato, apresentamos caso confirmado de meningoencefalite chagásica, como doença definidora de aids, em paciente com 318 linfócitos T-CD4+/mm3. Após 2 meses de tratamento seguido de um ano de profilaxia secundária com benzonidazol e início precoce de terapia antirretroviral (HAART), a paciente apresentou boa evolução clínica, parasitológica e radiológica. Utilizamos a reação em cadeia da polimerase qualitativa do T. cruzi, para monitorização da parasitemia por T. cruzi durante e após o tratamento. Ressaltamos o valor potencial das técnicas moleculares associadas aos parâmetros clínicos e radiológicos nos pacientes com doença de Chagas e infecção pelo HIV. A introdução precoce da terapia antirretroviral, a terapia antiparasitária prolongada, manutenção e descontinuação da mesma, são desafios atuais, embora possíveis, no manejo da reativação da doença de Chagas na era das terapias antirretrovirais de alta eficácia.

Meningoencefalitis chagásica en un paciente con infección por VIH/SIDA con sobrevida a tres años: caso clínico / Three-year survival of a patient with HIV and chagasic meningoencephalitis: case report

Immunocompromised patients as those with renal transplant, hematological neoplasia or cáncer and HIV/AIDS infection can suffer acute reactivation of Chagas disease. Central nervous system (CNS) evolvement (cerebral tumor or chagoma and diffuse meningoencephalitis) is similar to other opportunistic infections that present with cerebral expansive processes like toxoplasmosis or CNS primary lymphoma. Survival is infrequent, depending on antiparasitic therapy and early starting antiretroviral therapy. The case of an HIV/AIDS positive patient that evolved with a chagasic meningoencephalitis and improved after beginning early antiparasitic therapy and antiretroviral therapy antirretroviral is described.

Los pacientes inmunocomprometidos como los sometidos a trasplantes renales, con neoplasias hemato-oncológicas e infección por VIH/SIDA, pueden desarrollar reactivación aguda de la enfermedad de Chagas. El compromiso del sistema nervioso central-SNC (tumor cerebral o chagoma y meningoencefalitis difusa) es similar a otras infecciones oportunistas que cursan con procesos expansivos cerebrales como toxoplasmosis o linfoma primario del SNC. La sobrevida es poco frecuente, siendo prioritario para la buena evolución, la terapia antiparasitaria y el inicio de terapia antiretro viral. Se describe caso clínico de un paciente con infección por VIH/SIDA que cursó con meningoencefalitis chagásica con evolución satisfactoria tras el inico precoz de terapia antiparasitaria y terapia antiretro viral.

Meningoencefalitis Eosinofílica / Eosinophilic Meningoencephalitis

El Angiostrongylus cantonensis es la causa infecciosa más frecuente de meningoencefalitis eosinofílica en el niño en nuestro medio. El huésped definitivo de este nemátodo es la rata y los humanos se infectan por la ingestión de larvas en tercer estadio presentes en huéspedes intermediarios como caracoles terrestres, transportadores como camarones y algunos peces que se ingieren crudos o mal cocinados o en productos vegetales frescos, contaminados por las secreciones de los caracoles. Las larvas ingeridas penetran en los vasos intestinales hasta llegar a las meninges, donde mueren al cabo de poco tiempo y producen una reacción eosinofílica que se manifiesta como meningitis aséptica. De las al menos 20 especies descritas de Angiostrongylus, solo dos afectan al hombre: el nemátodo Angiostrongylus cantonensis, el gusano del pulmón de la rata, es la causa más frecuente de meningitis eosinofílica. Angiostrongylus (Parastrongylus) costaricensis es el agente causal de la angiostrongyliasis abdominal, o intestinal. Se hace una descripción de los síntomas clínicos de la meningitis eosinofílica, causados por la presencia de las larvas en el cerebro y por las reacciones locales del hospedero. En muchas ocasiones los pacientes se pueden recuperar, pero en algunos casos la evolución puede ser fatal, sobre todo en las infecciones masivas.Se hace referencia a las características epidemiológicas de la enfermedad, el diagnóstico y el tratamiento. Se presenta un caso, diagnosticado en el servicio Miscelánea H de nuestro hospital.

The Angiostrongylus cantonensis is the most frequent infectious cause of eosinophilic meningoencephalitis in children in our settings. The definitive host of this nematode is the rat and the humans get infected by ingesting larvae in the third stage that are present in intermediate hosts like snails, carriers like shrimps and several fish that are eaten raw or bad cooked, or in fresh vegetables contaminated by the secretions of the snails. The ingested larvae enter in to the intestinal vases until they arrive to the meninges, where they die soon, producing an eosinophilic reaction, manifested as aseptic meningitis. From the at least 20 species of Angiostrongylus described, only two affect humans. The nematode Angiostrongylus cantonensis , the worm of the rat lung, is the most frequent cause of the eosinophilic meningitis. The Angiostrongylus (Parastrongylus) costaricensis is the causal agent of the abdominal or intestinal angiostrongyliasis. We describe the clinical symptoms of the eosinophilic meningitis, caused by the presence of larvae in the brain and by the local reactions of the host. In many cases, the patient can recover, but in some cases the evolution can be fatal, especially when the infection is massive.

Primary amoebic meningoencephalitis: first reported case from Rohtak, North India

A fatal case of primary amoebic encephalitis (PAM) in a 20 year old boy, a proven case of acute leukemic leukemia (ALL) type L2, in remission is described. No history of swimming could be elicited. The clinical presentation, the isolation of the amoeba from the cerebrospinal fluid (CSF), the poor response to amphotericin B, and the ultimately fatal outcome are all consistent with the diagnosis of PAM. On the basis of its ability to grow at temperature 42ºC and 45ºC, morphology of trophozoite, and the presence of flagellate forms in CSF, the amoeba was identified as Naegleria fowleri. Other drugs used in combination with amphotericin B are tetracycline, rifampicin, and miconazole. A possibility of PAM should always be considered in all cases of acute purulent meningoencephalitis in which no bacteria or fungus are found.

Astrocytic and microglial response and histopathological changes in the brain of horses with experimental chronic Trypanosoma evansi infection / Resposta astrocítica e microglial e alterações histopatológicas no sistema nervoso central de eqüinos infectados cronicamente com Trypanosoma evansi

This study aimed to characterize astrocytic and microglial response in the central nervous system (CNS) of equines experimentally infected with T. evansi. The experimental group comprised males and females with various degrees of crossbreeding, ages between four and seven years. The animals were inoculated intravenously with 10(6) trypomastigotes of T. evansi originally isolated from a naturally infected dog. All equines inoculated with T. evansi were observed until they presented symptoms of CNS disturbance, characterized by motor incoordination of the pelvic limbs, which occurred 67 days after inoculation (DAI) and 124 DAI. The animals in the control group did not present any clinical symptom and were observed up to the 125th DAI. For this purpose the HE histochemical stain and the avidin biotin peroxidase method was used. Lesions in the CNS of experimentally infected horses were those of a wide spread non suppurative meningoencephalomyelitis.The severity of lesions varied in different parts of the nervous system, reflecting an irregular distribution of inflammatory vascular changes. The infiltration of mononuclear cells was associated with anisomorphic gliosis and reactive microglia was identified. The intensity of the astrocytic response in the CNS of the equines infected by T. evansi characterizes the importance of the performance of these cells in this trypanosomiasis. The characteristic gliosis observed in the animals in this experiment suggests the ability of these cells as mediators of immune response. The parasite, T. evansi, was not identified in the nervous tissues.

Este estudo objetivou caracterizar a participação astrocítica e microglial no sistema nervoso central (SNC) de eqüinos experimentalmente infectados com T. evansi. O grupo experimental foi formado por machos e fêmeas com vários graus de cruzamentos e idade variando entre quatro e sete anos. Os animais foram inoculados com 10(6) tripomastigotas de T. evansi, originalmente isolada de um cão infectado naturalmente. Todos os eqüinos inoculados foram observados até o aparecimento dos sintomas neurológicos, caracterizados por incoordenação motora dos membros pélvicos, o qual ocorreu entre 67 e 124 dias após a inoculação (DPI). Os animais do grupo controle não apresentaram sinais clínicos e foram observados até o 125º DPI. Para este propósito, foram utilizados os métodos histoquímicos (HE) e imunoistoquímicos do complexo avidina-biotina peroxidase (ABC). A lesão no sistema nervoso central (SNC) dos eqüinos infectados com T. evansi foi caracterizada como meningoencefalomielite não supurativa. A gravidade das lesões variou em diferentes segmentos do SNC, refletindo distribuição irregular das alterações vasculares. Infiltrado perivascular e meníngeo foi associado a gliose anisomórfica e microgliose reativa. A intensidade da resposta astrocítica no SNC dos equinos infectados com T. evansi caracteriza a importância da performance destas células nas tripanossomíases. A gliose observada nos animais deste experimento sugerem a habilidade destas células como mediadoras da resposta imune. T. evansi não foi identificado no parênquima do SNC.

First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Metastrongylidae) in Brazil

Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens), Subulina octona (157), Achatina fulica (45) and Bradybaena similaris (23). Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from São Vicente, state of São Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.

Acanthamoebae presenting as primary meningoencephalitis in AIDS.

A rare case of Acanthamoebae meningoencephalitis is diagnosed in cerebrospinal fluid (CSF) of a 24 years old male suffering from acquired immunodeficiency syndrome (AIDS) patient on the basis of bright field microscopy and culture growth on non-nutrient agar with Escherichia coli. This case illustrates that Acanthamoebae should be considered in the differential diagnosis of meningoencephalitis in AIDS in addition to tuberculosis and cryptococcus infection in tropical areas.

Aspectos clínicos e evolutivos da hidrocefalia na neurocisticercose / Clinical and evolutive aspects of hydrocephalus in neurocysticercosis

Com o propósito de analisar os aspectos clínicos da hidrocefalia (HDC) na neurocisticercose (NCC), realizou-se o estudo retrospectivo de 47 prontuários de pacientes com HDC e NCC. Verificou-se que 70,2 por cento eram homens, entre 21 e 50 anos. A hipertensão intracraniana (HIC) ocorreu em todos os pacientes, cefaléia (CEF) em 89,4 por cento, meningoencefalite (ME) em 80,8 por cento e distúrbios psíquicos (PSI) em 74,5 por cento. A síndrome liquórica da NCC foi detectada em 65,9 por cento pacientes. Além da HDC, as tomografias computadorizadas de crânio (TC) mostraram lesões císticas e edema cerebral difuso em 59,6 por cento cada, calcificações em 55,3 por cento. Dos 41 pacientes (87,2 por cento) com derivação ventriculoperitoneal (DVP), em 22 (53,7 por cento) deles foram necessárias uma a sete revisões/paciente (média=3). A evolução foi satisfatória em 51,1 por cento e fatal em 31,9 por cento. Conclui-se que a hidrocefalia é mais comum no sexo masculino em idade produtiva, tendo a HIC, CEF, MN e PSI como manifestações freqüentes e que, a necessidade de revisões de DVP, piora o prognóstico.

With the purpose to verify clinical aspects of hydrocephalus (HC) in patients with neurocysticercosis (NCC), a retrospective study of 47 patients was performed. The majority of patients (70.2 percent) were men aging 21-50 years. Intracranial hypertension (ICH) occurred in all patients, headache (HA) in 42 (89.4 percent), meningoencephalitis (ME) in 38 (80.8 percent) and psychiatric disorders (PD) in 34 (72.3 percent). The cerebrospinal fluid syndrome of NCC was detected in 31 patients (65.9 percent). In addition to HC, computed tomography (CT) scans showed cystic lesions in 28 (59.6 percent) patients, diffuse brain edema also in 28 (59.6 percent), and calcifications in 26 (55.3 percent). Shunts were inserted in 41 (87.2 percent) patients and 22 (53.7 percent) of them were submitted to 1-7 surgical revision/patient (mean=3) that were higher (mean=4) in those who died than in survivors (mean=2). Evolution was satisfactory in 24 (51.1 percent) patients and fatal in 15 (31.9 percent). It is possible to conclude that, in patients with NCC, HC occurs predominantly in men in productive life with ICH, HA, ME and PD as common manifestations, and the need for shunt revision makes patient's prognosis worse.

Meningoencefalitis amebiana primaria: comunicacion de dos nuevos casos Venezolanos / Primary amebic meningoencephalitis: two new cases report from Venezuela

La meningoencefalitis amebiana primaria (MAP) es infrecuente. Describimos dos nuevos casos de MAP en pacientes Venezolanos. Caso 1, Varón de 10 años, con fiebre, cefalea, vómitos y debilidad generalizada, y antecedente de inmersión en un estanque de agua días antes del inicio de sus síntomas, falleciendo 72 horas después del ingreso. Caso 2, Varón de 23 años con historia de cefalea, fiebre, vómitos, somnolencia y cambios de conducta. El paciente falleció 40 horas después. El estudio neuropatológico en ambos casos reveló MAP por Naegleria fowleri. La encefalitis por amebas anfizoicas debe sospecharse en casos de meningoencefalitis asépticas.

Primary amebic menigoencephalitis (PAM) is rare. Two cases of PAM in Venezuelan patients are described. Case 1, a 10 year-old male with headache, fever, vomiting. The patient swam in a water reservoir before the onset of his disease. He died during his third hospital day. Case 2, a 23 year-old male with a history of headache, fever, vomiting, drowsiness, and behavioral disturbances. The patient died on his second hospital day. The diagnosis in both cases was PAM due to Naegleria fowleri. Central nervous system infection by free-living amebas should be considered in meningoencephalitides with bacterial-free cerebro-spinal fluid.

sICAM-1 in meningoencephalitis due to Angiostrongylus cantonensis / sICAM-1 en meningoencefalitis por Angiostrongylus cantonensis

INTRODUCTION: Angiostrongylus cantonensis meningoencephalitis is an emergent disease in the Americas. METHOD: Twelve children suffering from eosinophilic meningoencephalitis due to this parasite aged between 6-10 years were studied. Cerebrospinal fluid (CSF) and serum samples were taken simultaneously in the first diagnostic puncture at admission. RESULTS: All cases showed typical findings on the routine CSF and serum analysis: increased CSF total protein, increased Q (CSF/serum) albumin accompanied by eosinophilia in CSF. No intrathecal synthesis of immunoglobulins was found. Mean serum and CSF sICAM-1 values were 337.4 and 3.97 ng/mL. Qalbumin and QsICAM-1 mean values were 4.1 and 6.2 respectively. In 50 percent of the patients an increased brain-derived fraction of sICAM-1 was found. CONCLUSION: It may be suggested that a dynamic of the sICAM-1 brain derived fraction is perhaps associated to the immune response in the evolution of the disease.sICAM-1 may be an agent in negative feedback for eosinophils passage through the blood-CSF barrier into the inflammatory brain response.

INTRODUCCION: La meningoencefalitis por Angiostrongylus cantonensis es una enfermedad emergente en las Américas. MÉTODO: Doce niños con meningoencefalitis eosinofílica por Angiostrongylus cantonensis con edades entre 6 y 10 años fueron estudiados. Se tomaron muestras simultáneas de suero y líquido cefalorraquídeo (LCR) en la primera punción lumbar diagnóstica. RESULTADOS: Todos los casos evidenciaron hallazgos típicos en los análisis de rutina del LCR y suero: incremento de proteínas totales, aumento de la razón albúmina Q (LCR/suero) acompañado de eosinofilia en LCR. No se encontró síntesis intratecal de inmunoglobulinas. Los valores medios de sICAM-1 en suero y LCR fueron de 337,4 y 3,97 ng/mL respectivamente. Los valores medios de Q albúmina y Q sICAM-1 fueron de 4,1 y 6,2 respectivamente. En el 50 por ciento de los pacientes se encontró un incremento de la fracción de sICAM-1 derivado del cerebro. CONCLUSION: Se puede sugerir que la dinámica de la fracción sICAM-1 derivada del cerebro ocurre quizas asociada a la respuesta inmune frente a la enfermedad. sICAM-1 puede ser un agente de retroalimentación negativa para el paso de eosinófilos de la sangre a través de la barrera sangre-LCR en el cerebro inflamado.

Infecciones por amebas de vida libre. Comentarios históricos, taxonomía y nomenclatura, protozoología y cuadros anátomo-clínicos / Infections caused by free-living amebas: historical commentaries, taxonomy and nomenclature, protozoology and clinicopathologic features

Infections caused by free-living amebae constitute one of emergent opportunistic infections with greatest medical interest. Although infrequently, they have been described in almost all world, its diagnosis depends on a high index of suspicion, especially in morpho-pathologic and laboratory studies. Exciting historical features of infections due to free-living amebae, its taxonomy and the present nomenclature are briefly reviewed. An analysis of the protozoology of the most frequent agents is done and, based on the author's own experience and the published one, already established anatomo-clinical entities are described: the primary amebic meningoencephalitis, granulomatous amebic encephalitis, Acanthamoeba keratitis, cutaneous acanthamoebiasis, disseminated infection and other rare isolated locations.

Meningoencefalitis granulomatosa por Balamuthia mandrillaris: Reporte de un caso y revisión de la literatura / Granulomatous amoebic meningoencephalitis by Balamuthia mandrillaris: case report and literature review

Durante los últimos años, otra ameba de vida libre, Balamuthia mandrillaris, ha sido identificada como agente etiológico de meningoencefalitis granulomatosa amebiana (MGA) en humanos. Presentamos el caso de una escolar de sexo femenino, inmunocompetente en quien se realizó el diagnóstico post mortem de MGA por este agente. Consultó por aparición de lesiones eritematosas e induradas que comprometían la zona centro-facial. En biopsia cutánea se evidenció una lesión granulomatosa con RPC positiva para secuencias génicas de Mycobacterium atípico, por lo que se inició tratamiento para micobacteriosis atípica extrapulmonar. Evolucionó con compromiso neurológico progresivo, falleciendo aproximadamente un año después de iniciar los síntomas. La necropsia reveló una MGA, cuyo estudio posterior demostró la presencia de B. mandrillaris. La infección por B. mandrillaris debe ser considerada en el diagnóstico diferencial de una enfermedad granulomatosa crónica que evoluciona con compromiso neurológico.

Meningoencephalitis by Naegleria fowleri: epidemiological study in Anzoategui state, Venezuela

Um caso de meningoencefalite amebiana primária, causada por Naegleria fowleri, foi diagnosticada no município de Independência no Estado de Anzoategui, Venezuela. Este caso motivou a realização deste estudo epidemiológico com o objetivo de identificar amebas de vida livre nessa área. Foram colhidas amostras representativas de água e realizadas análises fisicoquímicas e microbiológicas. Trofozoítos e cistos de Naegleria spp foram detectados em 44,4% (n=4). Verificou-se excelente concordância entre a observação das amebas de vida livre em esfregaços e aquelas de culturas monoxênicas em ágar não nutriente com Klebsiella pneumoniae (Kappa=1; p=0,003). Obteve-se uma carga variável de microrganismos mesófilos aeróbicos. As médias de mofos e leveduras foram de 3,0 CFU/ml (SD+2,0) e 102,9 CFU/ml(SD+32,2), respectivamente. Cem por cento das amostras apresentaram um número maior provável de coliformes totais e fecais de 240.000 NMP/100ml. Naegleria spp estava presente nas águas do município de Independência no Estado de Anzoategui, o que constitui um risco para a população que usa essas fontes.

Prolonged survival and immune reconstitution after chagasic meningoencephalitis in a patient with acquired immunodeficiency syndrome

Relatamos um caso de meningoencefalite devida ao Trypanosoma cruzi em um paciente com síndrome de imunodeficiência adquirida. O paciente apresentou convulsões e sinais neurológicos focais. O diagnóstico definitivo de meningoencefalite chagásica foi feito pela demonstracão de formas tripomastigotas livres no líquor. Foi iniciado benznidazol com melhora clínica e neurológica. As drogas antiretrovirais melhoraram a imunidade celular e três anos mais tarde o paciente tinha uma boa condicão clínica com reconstituicão imunológica e carga viral indetectável. A meningoencefalite chagásica tem um prognóstico ruim quando o tratamento específico não é iniciado ou quando há demora para substituí-lo. É necessário um alto índice de suspeita para o diagnóstico e tratamento precoces, especialmente em áreas endêmicas para a infeccão pelo Trypanosoma cruzi.

Primary amebic meningoencephalitis

This is the first case description of primary amebic meningoencephalitis [PAM] in an Iranian child. The patient was an eighteen months old boy referred to the hospital with signs and symptoms of acute meningitis. Cerebrospinal fluid [CSF] examination indicated pleocytosis with predominance of neutrophils, low sugar and high protein. Gram staining and culture of CSF for bacteria were negative. Microscopic examination of CSF revealed the motile amebae with pseudopodia. In Giemsa staining of CSF, the trophozoites of amebae were observed. The initial response to a six-week treatment course with amphotericin B, rifampin and chloramphenicol was satisfactory, but in the follow-ups the patient regressed neurologically. Although PAM is a rare and fatal disease, it should be differentiated from bacterial meningitis and treatment must be promptly carried out

Reactivation of Chagas' disease leading to the diagnosis of acquired immunodeficiency syndrome

Reactivation of chronic Chagas' disease is a rare condition and occurs only in immunosuppressed patients. We report a case of a patient with a rapid and fatal reactivation of Chagas' disease, manifested by meningoencephalitis, which lead to a diagnosis of acquired immunodeficiency syndrome (AIDS). We believe there is sufficient evidence to include the reactivation of Chagas' disease among the diagnostic criteria of AIDS in Human Immunodeficiency Virus (HIV) infection.

Meningoencefalites toxoplásmica e chagásica em pacientes com infecção pelo vírus da imunodeficiência humana: diagnóstico diferencial anatomopatológico e tomográfico / Toxoplasmic and chagasic meningoencephalitis in patients with human immunodeficiency virus infection: anatomopathologic and tomographic differential diagnosis

Em 22 pacientes com sorologia positiva para o vírus da imunodeficiência humana, com ou sem síndrome da imunodeficiência adquirida, dos quais 7 com meningoencefalite toxoplásmica e 15 com meningoencefalite chagásica associadas, procuraram-se dados diferenciais, entre as duas encefalopatias, tanto à anatomia patológica quanto à tomografia computadorizada do crânio. Os resultados observados e os dados da literatura nos permitiram concluir que enquanto na meningoencefalite necrosante focal por Toxoplasma gondii o acometimento dos núcleos da base é freqüente, na meningoencefalite necrosante focal causada pelo Trypanosoma cruzi, lesões dessas estruturas parecem não ocorrer ou ser excepcionais. De outro lado, o acometimento da substância branca parece nitidamente maior na meningoencefalite chagásica que na meningoencefalite toxoplásmica, ao passo que o parasitismo e a hemorragia do tecido nervoso, bem como as lesões das bainhas de mielina são mais freqüentes e intensos na meningoencefalite causada pelo Trypanosoma cruzi que naquela por Toxoplasma.

Twenty-two HIV+ patients with encephalitis were studied. Of these, 7 had meningoencephalitis due to Toxoplasma gondii (MT) and 15 due to Trypanosoma cruzi (MC). Pathologic and computerized axial tomography (CAT) changes were compared. We found that focal necrotizing encephalitis due to Toxoplasma involved the cerebral cortex and the basal ganglia, whereas lesions due to Trypanosoma cruzi were centered in the white matter, sometimes extending into the cortex. Hemorrhages, myelin lesions and organisms were more pronounced in chagasic than in toxoplasmic encephalitis. These findings are consistent with the literature reviewed.