Enfermedad de Chagas del sistema nervioso central en un paciente con SIDA demostrada por métodos cuantitativos moleculares / Chagas disease affecting the central nervous system in a patient with AIDS demonstrated by quantitative molecular methods

Although infrequent, Trypanosoma cruzi reactivation is possible among patients with HIV/AIDS infection that develop a tumor-like or granulomatous lesion in the CNS. We report the case of a 60 years old male patient with HIV/AIDS and low CD4 lymphocytes count with cerebellar symptoms and mild paresis, associated to supra and infratentorial hypodense lesions and positive serology tests both to T. gondii and Trypanosoma cruzi. Empirical therapy against toxoplasmosis was prescribed together with antiretroviral therapy but without a favorable response. Brain Chagas disease was confirmed by quantitative PCR in the CSF but he died despite nifurtimox treatment. Despite its rare occurrence, Chagas disease affecting the CNS is possible among patients with HIV/AIDS infection. Epidemiological exposure, a positive Chagas serological test and the image pattern of brain lesions support the suspicion. Diagnosis can be confirmed by molecular test in CSF samples, including new quantitative methods. Despite an adverse prognosis, specific therapy can be attempted besides antiretroviral treatment.

La reactivación de la infección por Trypanosoma cruzi es un diagnóstico infrecuente pero posible en pacientes con infección por VIH/SIDA y una lesión de tipo tumoral o granulomatosa en el sistema nervioso central. Presentamos el caso clínico de un paciente de 60 años con VIH/SIDA y recuentos bajos de linfocitos CD4, con síntomas cerebelosos y paresia leve, lesiones hipodensas supra e infratentoriales y serología positiva para Toxoplasma gondii y T. cruzi. Se trató empíricamente como una toxoplasmosis cerebral y con terapia antiretroviral, sin respuesta clínica. La enfermedad de Chagas cerebral se confirmó por RPC cuantitativa en el LCR. El paciente falleció a pesar de recibir terapia con nifurtimox. Apoyan la posibilidad de un Chagas cerebral en pacientes con VIH/SIDA, la exposición epidemiológica, la serología positiva y el patrón de distribución de las lesiones en las imágenes. El diagnóstico puede mejorarse con técnicas moleculares cuantitativas en LCR. A pesar de su mal pronóstico, se puede intentar una terapia específica junto al tratamiento antiretroviral.

Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii / Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii

Introducción. No existen reportes sobre las variaciones en la secuencia de los genes blanco de los medicamentos anti- Toxoplasma en aislamientos provenientes de Suramérica. Objetivo. Clonar y secuenciar los genes de la dihidrofolato-reductasa ( dhfr ) y la dihidropteroato-sintetasa ( dhps ) de la cepa de referencia RH y de dos aislamientos colombianos de Toxoplasma gondii. Materiales y métodos. Se obtuvieron dos aislamientos de T. gondii en líquido céfalorraquídeo de pacientes colombianos positivos para HIV con toxoplasmosis cerebral. Se extrajo el ADN de los genes dhfr y dhps y se amplificaron mediante reacción en cadena de la polimerasa (PCR). Los productos fueron clonados en el vector pGEM-T y secuenciados. Resultados. Se encontró un cambio de adenina por guanina (A « G) en la posición 235 del exón 2 del gen dhps , dos cambios de guanina por citocina (G « C) en las posiciones 259 y 260 y un cambio de timina por guanina (T « G) en la posición 371 del exón 4 del gen dhps. Por análisis bioinformático, en este último exón se identificó un polimorfismo no sinónimo en la región codificante, que podría llevar al cambio de una Glu (CAA o CAG) por una His (codificada por los codones AAU o AAC). Se calculó el modelo estructural de la enzima dihidropteroato-sintetasa (DHPS) de T. gondii y se identificaron las modificaciones en la estructura secundaria ocasionadas por las mutaciones. Conclusiones. La metodología estandarizada puede servir como base para la búsqueda de polimorfismos en muestras de pacientes con diferentes manifestaciones clínicas de toxoplasmosis y para establecer su posible relación con los cambios en la sensibilidad a los antifolatos y la reacción al tratamiento.

Introduction: There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates. Objective: This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . Materials and methods: Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced. Results: One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations. Conclusions: The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.

A Fatal Case of Naegleria fowleri Meningoencephalitis in Taiwan

After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.

Primary amoebic meningoencephalitis due to Naegleria fowleri.

Primary amoebic meningoencephalitis (PAM) due to Naegleria fowleri was detected in a 36-year-old, Indian countryman who had a history of taking bath in the village pond. He was admitted in a semi comatosed condition with severe frontal headache, neck stiffness, intermittent fever, nausea, vomiting, left hemiparesis and seizures. Computerized tomography (CT) scan of brain showed a soft tissue non-enhancing mass with erosion of sphenoid sinus. However CSF findings showed no fungal or bacterial pathogen. Trophozoites of Naegleria fowleri were detected in the direct microscopic examination of CSF and these were grown in culture on non-nutrient agar. The patient was put on amphotericin-B, rifampicin and ceftazidime but his condition deteriorated and was taken home by his relatives in a moribund condition against medical advice and subsequently died. A literature review of 7 previous reports of PAM in India is also presented. Four of theses eight cases were non lethal. The mean age was 13.06 years with male: female ratio of 7:1. History of contact with water was present in four cases. Trophozoites could be identified in all 8 cases in this series.

Acanthamoeba encephalitis.

Central nervous system infection with free-living amoebae is rare. We present a fatal case of Acanthamoeba encephalitis in a 63-year-old female from India where acanthamoebae were demonstrated and cultured from CSF. In spite of treatment with amphotericin B, fluconazole and rifampicin the patient did not survive. Amoebic infection should be suspected in a patient of encephalitis of unexplained aetiology as timely diagnosis can lead to a favourable outcome.

Comparison of different techniques for the diagnosis of parasitic infections among leukemic children

Acute lymphocytic leukemia [ALL] is a worldwide problem, and it is more prevalent in children. As the chemotherapy is taken, the host defenses are altered and the patient becomes more liable to infection. This study aimed at determining the frequency of parasitic infections among children with ALL in relation to controls, and to evaluate the different techniques used in the diagnosis of these infections. The study was carried out in Alexandria University Children's Hospital at El-Shatby during one year. The study included 117 children with ALL, and same number of immunocompetent children as a control group. Stool, urine, cerebrospinal fluid [CSF], and blood samples were collected and prepared to be examined by different techniques. The overall percentages of parasitic infections were 90.6% and 58.1% among leukemic children and controls, respectively. Microsporidiosis was the most prevalent infection, and Cryptosporidium parvum was the most common coccidial infection. Microsporidium was the only parasite detected in the CSF of leukemic children. The best technique was modified Ziehl Neelsen to detect coccidia, Trichrome stain for protozoa and Quick-Hot Gram-chromotrope stain for microsporidial infection. There was a high percentage of parasitic infections among Jeukemic children, and the results indicate that the combination of many techniques is more likely to be effective in the diagnosis of these infections

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.

Líquido cefalorraquidiano no diagnóstico da esquistossomose raquimedular / Cerebrospinal fluid in the diagnosis of spinal schistosomiasis

As três espécies de esquistossoma podem comprometer o sistema nervoso. O S. mansoni é responsável pela esquistossomose no Brasil, sendo a mielopatia uma forma grave desta helmintose. O propósito deste trabalho é analisar as alterações do líquido cefalorraquidiano (LCR) para dar mais subsídios para o diagnóstico da esquistossomose raquimedular. Fizeram parte deste estudo 22 amostras de LCR de pacientes com esquistossomose espinal. Os resultados das análises destas amostras mostraram que a associação de alterações do LCR com quadro inflamatório e RIFI-IgM positiva ocorreu em 88 por cento dos pacientes, que o eosinófilo esteve presente em apenas 7 amostras (36,8 por cento), e que 3 dos 22 pacientes estudados apresentaram LCR normal. Conclui-se que o exame de LCR é coadjuvante muito útil para o diagnóstico da neuroesquistossomose.

Prognostic factors relating to outcome of severe malaria among children in Bangladesh.

This study was done in the Paediatric in-patient department of Chittagong Medical College Hospital (CMCH), Chittagong, Bangladesh to identify and quantify the prognostic factors associated with increased mortality in severe malaria (SM) cases. All the patients with parasitologically confirmed clinical syndromes of SM, admitted between June 1997 and May 1998, were included. A total of 53 consecutive cases were studied. Cerebral malaria (CM) was the commonest type of SM, observed in 36(68%) cases, second commonest type was severe anaemia 13(25%). More than one type of severe manifestations were present in 23(44%) cases. Overall case fatality rate (CFR) was 17% and it was 30% among those who had multi-organ manifestations. Important poor prognostic clinical variables were Blantrye coma score (BCS) score of 0 and 1 on day 1 (OR = 7.78) and day 2(OR = 40.0), multi-organ manifestations (OR = 6.8) and in-hospital complications (OR = 5.18). Important poor prognostic laboratory variables were day 2 parasite count > 50,000/cmm (OR = 5.5), blood glucose < 2.2 mmol/l (OR = 21.5) and raised CSF protein > 50 mg/dl (OR = 7.0). It can be concluded that certain clinical variables e.g. low BCS on day 1 & 2, multi-organ manifestations, in-hospital complications; and laboratory variables e.g. high parasite count, low blood glucose level, raised CSF protein levels are associated with increased mortality rate in SM cases.

Polymerase chain reaction for the laboratory diagnosis of aseptic meningitis and encephalitis

A protocol for testing cerebrospinal fluid specimens using a range of PCR assays for the diagnosis of central nervous system infection was developed and used to test prospectively 383 specimens. PCR assays were used for the detection of adenovirus, Borrelia burgdorferi, enteroviruses, Epstein Barr virus, cytomegalovirus, herpes simplex virus, human herpes virus type 6, JC virus, Leptospira interrogans, Listeria monocytogenes, lymphocytic choriomeningitis virus, measles virus, mumps virus, Mycobacterium sp., Mycoplasma pneumoniae, Toxoplasma gondii and varicella zoster virus. Of the 383 specimens tested in this study, 46 (12.0 percent) were found to be positive. The microorganisms detected were CMV, enterovirus, Epstein Barr virus, herpes simplex virus, human herpes virus type 6, JC virus, L. monocytogenes, Mycobacterium genus, Toxoplasma gondii and varicella zoster virus. The introduction of the PCR protocol described has improved the diagnosis of a range of central nervous system infections in our laboratory. We believe however that further evaluation of these assays in immunocompromised patients is necessary to better determine the predictive value of positive PCR results in these patient groups

Cisticercosis cerebral. Elevación de la inmunoglobulina G y su correlación clínica / Cerebral cysticercosis: the clinical correlation of immunoglobulin G levels

La cisticercosis cerebral es una enfermedad pleomórfica y heterogénea. El diagnóstico se realiza mediante métodos de imagen y por estudios inmunológicos. La severidad de la reacción inflamatoria se mide a través de los estudios en LCR. Realizamos un estudio prospectivo en 44 pacientes con cisticercosis cerebral, con la finalidad de evaluar la elevación de la inmunoglobulina G en el LCR. Los pacientes con cisticercosis mixta, parenquimatosa y subaracnoidea (Grupo III) tuvieron un promedio mayor de inmunoglobulina G, que aquellas con cisticercosis parenquimatosa (Grupo II) o con calcificaciones (Grupo I) (p< 0.001). Pensamos que la IgG puede ser un parámetro clínico) más para valorar el curso de la enfermedad.

El micrometodo de concentracion para diagnostico de la borreliosis / Concentration micromethod for the diagnosis of borreliosis

Las fiebres recurrentes son producidas por espiroquetas del genero Borrelia y transmitidas a otros por garrapatas y piojos. Nosotros hemos estudiado la sensibilidad y especificidad de un micrometodo de concentracion para el diagnostico de la Borreliosis en sangre. Se tomo sangre de ratones que fueron inoculados previamente con una cepa de Borrelia de origen humano. Tubos de micro-hematocrito fueron llenados con sangre, centrifugados y observados a traves del microscopio. La observacion se realiza en la interface de los globulos rojos y el plasma. El micrometodo se muestra mas sensible cuando los niveles de bacteremia son bajos

Primary amoebic meningoencephalitis: a first reported case in Thailand.

A case of primary amoebic meningoencephalitis caused by Naegleria, from Sisaket province of Thailand is first reported. A 5-year old Thai with boy a history of swimming in a pond along a rice field before the onset of this illness, was admitted to the provincial hospital for chief complaints of headache, high fever, vomiting and drowsiness for 4 days. On admission he had convulsions and became comatosed with signs of meningeal irritation. The cerebrospinal fluid was similar to pyogenic meningitis but numerous amoebae were found and identified as Naegleria sp. Unfortunately, specific treatment was not administered promptly, the patient died 3 days after admission.