RESUMO
Species of Naegleria, Acanthamoeba, and Balamuthia are soil amoebae that can cause encephalitis in animals and humans. Of these, Naegleria fowleri is the cause of often fatal primary meningoencephalitis in humans. N. fowleri-associated encephalitis was diagnosed in a cow that was suspected to have rabies. Only formalin-fixed brain was available for diagnosis. There was severe meningoencephalitis involving all parts of the brain and numerous amoebic trophozoites were present in lesions. The amoebae reacted with N. fowleri-specific polyclonal antibodies in an indirect immunofluorescent antibody test. This is the first report of amoebic encephalitis in any host from Costa Rica.
Assuntos
Amebíase/veterinária , Doenças dos Bovinos/diagnóstico , Meningoencefalite/veterinária , Naegleria fowleri/isolamento & purificação , Amebíase/diagnóstico , Amebíase/patologia , Animais , Bovinos , Doenças dos Bovinos/patologia , Costa Rica , Evolução Fatal , Feminino , Meningoencefalite/diagnóstico , Meningoencefalite/patologiaRESUMO
Pulmonary amoebiasis without liver involvement occurs sporadically as a result of haematogenous spread from a primary site, the colon. The case history is presented of a patient who developed superior vena cava syndrome due to a pulmonary amoebic abscess without liver involvement. He was initially suspected of having a neoplasm but a combination of tests including histological examination of the H&E stained excised tissue, immunofluorescence using anti-Entamoeba histolytica antibodies, and serology confirmed the diagnosis of amoebiasis. To our knowledge this is the first description of pulmonary amoebiasis presenting as superior vena cava syndrome.
Assuntos
Amebíase/complicações , Pneumopatias Parasitárias/complicações , Síndrome da Veia Cava Superior/parasitologia , Adulto , Animais , Abscesso Encefálico/parasitologia , Entamoeba histolytica , Humanos , Masculino , Tomografia Computadorizada por Raios X/métodosRESUMO
INTRODUCTION: Infection of the Central Nervous System by free living amebas is an unusual event, 344 cases have been reported to date. The disease becomes evident in two different clinical fashions: Primary Amebic Meningoencephalitis (PAM) caused by Naegleria fowleri and Granulomatous Amebic Encephalitis (GAE) induced by Spp. of Acanthamoeba and Balamuthia. CLINICAL CASES: The authors report three new cases from Venezuela. Case 1. 34 years old man, with a chief complaint of general malaise, headache and fever, a diagnosis of common cold was made and the patient was treated as such, he did not improve and was admitted to the hospital with deterioration of his clinical status; the patient died 10 days after the onset of his illness which was determined to be GAE produced by Balamuthia mandrillaris. Case 2. 8 years old female admitted to the hospital because of fever, headache and generalized seizures of sudden onset; neurocysticercosis was diagnosed and following improvement the patient was discharged and readmitted on two occasions because of relapse and worsening of her illness, she died 2 months after the onset of her disease that was diagnosed by autopsy as GAE due to Balamuthia mandrillaris. Case 3. 16 years old male, previously healthy, who following immersion in a water tank was admitted to the hospital because of meningeal irritation that progressed to coma and death in a 7 day lapse; autopsy revealed PAM by Naegleria fowleri. The two cases of GAE due to Balamuthia mandrillaris occurred in apparently immunocompetent individuals, contrary to the statement that these microorganisms are opportunistic. CONCLUSION: We believe that neurological infection by amphizoic amebas is being underdiagnosed, probably due to ignorance regarding this pathology or because of a very low autopsy rate in most countries.
Assuntos
Amebíase/parasitologia , Granuloma/parasitologia , Meningoencefalite/parasitologia , Naegleria fowleri , Adolescente , Adulto , Amebíase/diagnóstico , Amebíase/epidemiologia , Animais , Criança , Cisticercose/diagnóstico , Diagnóstico Diferencial , Evolução Fatal , Feminino , Água Doce/parasitologia , Granuloma/diagnóstico , Granuloma/epidemiologia , Humanos , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/epidemiologia , Natação , Venezuela/epidemiologiaRESUMO
In this report, we describe four cases of granulomatous amebic encephalitis caused by Balamuthia (Leptomyxid ameba) in four previously healthy Mexican patients. All four cases were characterized by focal neurologic signs, increased intracranial pressure, and cerebral hyperdense lesions in computed tomography scans of the head. These patients underwent craniotomies for evaluation of mass lesions for possible brain tumors. Granulomatous chronic inflammatory reaction and amebic trophozoites were found in brain biopsies. At autopsy, areas of hemorrhagic encephalomalacia were located in both basal frontal lobes, right parieto-occipital lobes, and, less often, in the brainstem and cerebellum. Angiitis, necrotizing granulomatous encephalitis, and large numbers of amebic trophozoites in perivascular spaces were present. Amebic trophozoites were seen in the left adrenal gland in one of the cases. The amebas in all four cases were identified as Balamuthia mandrillaris (Leptomyxiidae) based on their reactivity with the anti-Balamuthia (Leptomyxiidae) serum in an immunofluorescence test.
Assuntos
Amebíase/patologia , Amoeba/isolamento & purificação , Encefalite/patologia , Adolescente , Adulto , Amebíase/parasitologia , Amoeba/classificação , Animais , Criança , Pré-Escolar , Encefalite/parasitologia , Evolução Fatal , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , MéxicoRESUMO
Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris are known to cause fatal central nervous system (CNS) disease in human beings. N. fowleri causes acute, fulminating primary amebic meningoencephalitis (PAM), which generally leads to death within 10 days. Acanthamoeba spp. and B. mandrillaris cause chronic granulomatous amebic encephalitis, which may last for 8 weeks. Acanthamoeba spp. and B. mandrillaris also cause CNS disease in animals. N. fowleri, however, has been described only in human beings. This report is the first of PAM in an animal, a South American tapir. Dry cough, lethargy, and coma developed in the animal, and its condition progressed to death. At necropsy, lesions were seen in the cerebrum, cerebellum, and lungs. The CNS had severe, suppurative meningoencephalitis with many neutrophils, fibrin, plasma cells, and amebas. Amebas were 6.5 microns to 9 microns in diameter and had a nucleus containing a large nucleolus. Amebas in the sections reacted with a monoclonal antibody specific for N. fowleri in the immunofluorescent assay and appeared bright green.
Assuntos
Amebíase/patologia , Amebíase/veterinária , Meningoencefalite/patologia , Meningoencefalite/veterinária , Naegleria fowleri , Perissodáctilos/parasitologia , Animais , Masculino , Naegleria fowleri/isolamento & purificação , América do SulRESUMO
Granulomatous amebic encephalitis (GAE), or meningoencephalitis due to Acanthamoeba spp. and leptomyxid ameba are uncommon CNS infections that generally occur in immunocompromised hosts. We describe a case of GAE caused by Balamuthia mandrillaris previously designated as a leptomyxid ameba, in an apparently healthy 14-year-old Venezuelan boy. This case was characterized by sudden onset of seizures, focal neurologic signs and by a prolonged clinical course (from November 1992 to March 1993). Neuroimaging studies showed cerebral hypodense lesions in cerebral hemispheres, brain stem and cerebellum. Microscopically, we found a chronic granulomatous inflammatory reaction with necrotizing angiitis, large numbers of amebic trophozoites and few cysts in perivascular spaces and within necrotic CNS tissue. The amebas were identified as B. mandrillaris based on their immunofluorescence reactivity with the anti-B. mandrillaris serum. So far, 30 cases of GAE due to B. mandrillaris have been recognized in humans, two in AIDS patients. No visceral involvement by free-living amebas or any other significant abnormality was observed. This patient developed "spontaneous" GAE, but it remains possible that an undiagnosed abnormality in cell-mediated immunity or a deficient humoral immune response may explain the susceptibility of this patient to this opportunistic infection.
Assuntos
Amebíase , Encefalite/microbiologia , Granuloma/microbiologia , Adolescente , Amebíase/metabolismo , Amebíase/patologia , Cadáver , Encefalite/patologia , Granuloma/patologia , Humanos , MasculinoRESUMO
Five Naegleria strains isolated from patients with primary amebic meningoencephalitis and one strain isolated from the water of an artificial canal were investigated. All strains were pathogenic for mice when instilled intranasally and showed cytopathic effects in Vero cell cultures. Their growth characteristics (isolation and subculture at 45 degrees C), serological results, and isoenzyme patterns permitted us to identify the six strains as Naegleria fowleri. This is the first time that Naegleria fowleri has been isolated from patients with primary amebic meningoencephalitis in Mexico.
Assuntos
Amebíase/epidemiologia , Meningoencefalite/etiologia , Naegleria fowleri , Fosfatase Ácida/análise , Adolescente , Animais , Hidrolases de Éster Carboxílico/análise , Criança , Água Doce , Humanos , Lactente , Isoenzimas/análise , México/epidemiologia , Camundongos , Naegleria fowleri/enzimologia , Naegleria fowleri/isolamento & purificação , Naegleria fowleri/patogenicidade , Células Vero , Virulência , Microbiologia da ÁguaRESUMO
A 29-year-old Haitian man with acquired immunodeficiency syndrome presented with nasal obstruction and epistaxis. A computed tomogram of the head showed thickened nasal and paranasal sinus mucosa. A biopsy specimen of the turbinate disclosed inflammatory tissue containing amoebic trophozoites. The patient was empirically treated with rifampin and ketoconazole. He died four months after biopsy of other complications of acquired immunodeficiency syndrome. At autopsy, the amoebic infection was found only in the paranasal sinuses, a calf nodule, and in an intradermal abscess in the left leg. Pneumocystitis carinii pneumonia, Mycobacterium avium-cellulare in the liver and retroperitoneal lymph nodes, cytomegalovirus infection of the adrenal glands, and Kaposi's sarcoma in the spleen were additionally present. The organism was cultured and studied by electron microscopy, dark-field microscopy, and immunofluorescence.