Infección pulmonar por Lophomonas sp en una paciente con leucemia mieloide aguda / Lung infection by lophomonas spp. in a female patient with acute myeloid leukemia

RESUMEN Las infecciones por protozoos son prevalentes a nivel mundial, en particular en pacientes inmunosuprimidos. Comunicamos el caso de una paciente procedente de la ciudad de Viña del Mar, Chile, portadora de leucemia mieloide aguda en quiense confirmó una infección por Lophomonas sp. en lavado bronquioalveolar. Se manejó con antibióticos, pero falleció decomplicaciones de su enfermedad de base. Existe poca literatura disponible respecto a este microorganismo. Concluimos que debe considerarse a Lophomonas sp. como posibilidad diagnóstica si se encuentran protozoos en lavados bronquioalveolares de pacientes inmunosuprimidos.

ABSTRACT Protozoic infections are prevalent worldwide, particularly in immunosuppressed patients. We reported the case of a patient from the city of Viña del Mar, Chile, a carrier of acute myeloid leukemia in whom an infection by Lophomonas sp. was confirmed by bronchoalveolar lavage. She was treated with antibiotics but died of complications of the underlying disease. There is little literature available on this microorganism. We conclude that Lophomonas sp. should be considered as a diagnostic possibility if protozoa are found in bronchoalveolar lavage of immunosuppressed patients.

Hallazgos epidemiológicos en infecciones parasitarias intestinales de un grupo de niños ingresados por diarreas / Epidemiological findings in intestinal parasitic infections from a group of hospitalized children with diarrhea

Introducción: la enfermedad diarreica es aún una causa importante de mortalidad en países en desarrollo, en los que afecta principalmente a los niños menores de 5 años de edad. En Cuba, aunque la mortalidad por esta causa se ha reducido, puede ser un importante problema de salud en ciertas épocas del año. Entre los grupos de agentes biológicos que se pueden encontrar en niños con diarreas están los parásitos, de los cuales no siempre se conoce bien su papel como agente causal. Objetivo: determinar algunas características epidemiológicas de las infecciones parasitarias en niños ingresados con diarrea. Métodos: se realizó un estudio observacional descriptivo en niños ingresados con diarrea en la sala de gastroenterología del hospital pediátrico William Soler de La Habana, desde noviembre de 2006 a octubre de 2007. A todos los niños se les recogieron muestras de heces para estudios parasitológicos y se les llenó un cuestionario con datos clínicos y epidemiológicos. Resultados: se encontró una mayor frecuencia de infecciones por protozoos para todas las edades (p< 0,01); el grupo mayor de 2 años resultó el más frecuente infectado en general (68,52 porciento) y el más parasitado por Giardia lamblia (35,18 porciento), mientras que los lactantes presentaron la menor frecuencia de parasitismo intestinal (18,18 porciento). Las infecciones por protozoos en general y por el complejo Entamoeba histolytica/Entamoeba dispar en particular, fueron más frecuentes en la estación de lluvia que en la de seca (p< 0,05). Por último, se encontró que los niños asistentes a círculos infantiles y a escuelas primarias, presentaron una mayor frecuencia de infección con Giardia lamblia que por Entamoeba histolytica/Entamoeba dispar y Cryptosporidium (p< 0,05). Conclusiones: se encontró un predominio de infecciones por protozoos en niños ingresados con diarreas, las cuales se presentaron más frecuentes en los mayores de 2 años y en la estación de lluvia

Introduction: acute diarrhea is a major cause of mortality in developing countries, and children aged less than five years are the most affected. Despite of decreasing mortality rates in Cuba, this illness may be an important health problem in some periods of the year. Among the groups of biological agents found in children with diarrhea are the parasites but their role as etiological agent is not always well recognized. Objective: to determine some epidemiological characteristics of parasitic infections in hospitalized children due to diarrhea. Methods: an observational descriptive study was performed on children who had diarrhea and were admitted to the gastroenterology service ward in William Soler pediatric hospital in Havana from November 2006 to October 2007. Their stool samples were collected for parasitological studies, and some questionnaires were filled out with corresponding clinical and epidemiological data. Results: the frequency of protozoan infections was higher than that of helminthic ones for all the age groups(p< 0.01), and children aged over 2 years was the most frequently infected with all types of parasites in general (68.52 percent), and with Giardia lamblia (35.18 percent) in particular whereas the infant group was the less frequently infected with intestinal parasites (18.18 percent). The infections caused by protozoa and by Entamoeba histolytica/Entamoeba dispar were more frequent in the rainy season than in the dry season (p< 0.05). Finally, a higher prevalence of infections with Giardia lamblia than with Entamoeba histolytica/Entamoeba dispar or Cryptosporidium was found in day care and primary school children (p< 0.05). Conclusions: a higher prevalence of protozoan infections was observed and they occur more frequently in children aged more than two years old and during the rainy season

Infección por entamoeba histolytica / E. dispar determinada por dos métodos en vendedores de mercados, Honduras / Entamoeba histolytica/E. dispar infection determined by two methods in market vendors, Honduras

Antecedentes: Existe dificultad laboratorial para reconocer infecciones por Entamoeba histolytica en Honduras. El objetivo de este estudio fue comparar dos métodos de examen de heces para identificación de E. histolytica/E. dispar y determinar frecuencia de otros parásitos intestinales entre vendedores de dos mercados capitalinos. Sujetos y Métodos: A través de una organización no gubernamental que atendía una población de 322 vendedores (Agosto 2005), se les invitó a participar en el estudio previo consentimiento informado. Se examinó una muestra de heces de cada participante por microscopía y por prueba inmunoenzimática colorimétrica (ELISA) para identificar infección por Entamoeba histolytica. Se identificaron otros parásitos intestinales. Resultados: Se estudiaron 117 participantes, 88.8% mujeres y edad media de 37 años. No se reconoció casos de amebiasis invasora aguda por E. histolytica. Del total de treinta y cuatro (29.0%) infeccionespor E. histolytica/E. dispar, 11 (9.4%) se diagnosticaron por microscopía (quistes tetranucleados >10pm de tamaño), 10 (8.5%) por ELISA y13 (11.0%) infecciones adicionales con ambas pruebas. La prueba de ELISA utilizada no diferenció entre especies patógena (E. histolytica) y comensal (E. dispar); su sensibilidad fue 54% con especificidad de 86%. Noventa y siete (82.9%) participantes estaban multiparasitados detectados por microscopía, con especies de helmintos o protozoos patógenos y/o comensales, reflejo de ambiente insalubre. Conclusiones: Se necesitan pruebas confiables de tecnología adecuada aplicables en laboratorios de salud pública para determinar la distribución e importancia de infecciones por E. histolytica y por E. dispar en países en desarrollo como Honduras...

Detection of Cryptosporidium spp and other intestinal parasites in children with acute diarrhea and severe dehydration in Rio de Janeiro

The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3 percent) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7 percent) samples examined via the direct or Ritchie methods. Other parasites identified were Ascaris lumbricoides (4.2 percent), Blastocystis hominis (1.4 percent), Entamoeba coli (0.9 percent), Entamoeba histolytica/Entamoeba dispar (0.5 percent), Endolimax nana (0.5 percent), Trichuris trichiura (0.5 percent) and Enterobius vermicularis (0.5 percent).

O objetivo do presente estudo foi estimar a freqüência das infecções por Cryptosporidium spp e outros parasitas intestinais em crianças desidratadas com gastroenterite, internadas em um hospital pediátrico. Exames de fezes de 218 crianças foram realizados. Cryptosporidium spp foi detectado em 18 de 193 (9,3 por cento) amostras fecais submetidas à coloração pela safranina/azul-de-metileno. Giardia lamblia foi detectada em dez de 213 (4,7 por cento) amostras submetidas ao exame direto ou ao método de Ritchie. Também foram identificados Ascaris lumbricoides (4,2 por cento), Blastocystis hominis (1,4 por cento), Entamoeba coli (0,9 por cento), Entamoeba histolytica/Entamoeba dispar (0,5 por cento), Endolimax nana (0,5 por cento), Trichuris trichiura (0,5 por cento) and Enterobius vermicularis (0,5 por cento).

Intestinal protozoal infestation profile in persistent diarrhea in children below age 5 years in western Nepal.

Unlike acute diarrhea, the role of pathogens in persistent diarrhea in children in Nepal is unclear. Protozoal parasites are suspected to be a major cause. The study was carried out to find the association between protozoal agents and persistent diarrhea in children below age 5 years from western Nepal. Stool samples were collected from 253 children with persistent diarrhea, from 155 children with acute diarrhea (disease controls) and from 100 healthy children from the community (normal controls). Of 253 children with persistent diarrhea, 90 (35.5%) had protozoal infections, 63 (24.9%) helminthic infections, 32 (12.6%) had bacterial infections and 16 had mixed infections. Giardia lamblia was the most prevalent (67.7%), followed by Entamaeba histolytica (27.7%). HIV infection and severe malnutrition were associated with Cyclospora cayetanensis and Cryptosporidium spp causing persistent diarrhea. We conclude that stool microscopy should be routinely performed in children with persistent diarrhea since protozoal infections can be cured with effective treatment and control can be achieved by proper health education.

Protozoan enteric infection in AIDS related diarrhea in Thailand.

The aim of this study was to determine the prevalence of enteric protozoa and other pathogens in AIDS patients with diarrhea in Bangkok, Thailand. Of 288 consecutive patients screened in the 10 month period between November 1999-August 2000 inclusive, 55 (19.2%) had Cryptosporidium spp, 13 (4.5%) had Isospora oocyst, 11 (3.8%) had Giardia lamblia, 3 (0.9%) had Entamoeba histolytica, and 1 (0.3%) had Iodamoeba butschlii infection. The prevalence of microsporidia was 11% in this study. Of 251 patients for whom stool culture for bacteria was performed, enteric bacterial pathogens isolated were Campylobacter spp in 18 (7.1%), Salmonella spp in 11 (4.3%), and Shigella spp in 1 (0.5%). Other pathogens found in these patients were Clostridium difficile in 16/102 (15.6%). Mycobacterium spp in 18/287 (6.2%), and Strongyloides stercoralis in 23/288 (8.0%). Overall, parasitic and bacterial pathogens were identified in 140 (48.6%) patients. These pathogens were identified by the routine simple wet smear technique in 32, formalin-ether concentration method in 46, culture for S. stercoralis in 5, and culture for bacteria in 30. Additional test, using modified Ziehl-Neelsen staining, identified cryptosporidial oocyst, isospora oocyst, and Mycobacterium spp in 72. The microsporidia, initially identified by modified trichrome blue staining, all were then determined to be Enterocytozoon bieneusi by thin sectioning electron microscopy. Protozoan and bacterial pathogens were confirmed to be important etiologic agents in diarrhea in AIDS in Thailand. They were all associated with increased mortality. Routine stool examination by simple wet smear detected only one-fourth of these pathogens. Therefore all diagnostic techniques for these organisms should be made more widely available in Thailand.

Parasitoses intestinais no período infantil / Intestinal parasitoses in childhood

Os autores atualizam os aspectos mais importantes das parasitoses intestinais que ocorrem na infância, subdividindo-as em dois grandes grupos: helmintíases e protozooses. Em cada caso discorre sobre o agente etiológico, quadro clínico e diagnóstico, detendo-se particularmente no estudo da terapêutica, em que säo relacionados os medicamentos utilizados em cada uma das parasitoses, pela denominaçäo genérica do sal e as denominaçöes comerciais dos produtos correspondentes disponíveis no mercado farmacêutico.

Infections by protozoa in immunocompromised hosts

Protozoa are among the most important pathogens that can cause infection in immunocompromised patients. They infect particularly individuals with impaired cell immunity, such as those with hematologic neoplasias, those submitted to transplant of solid organs, those under high-dose corticosteroid therapy, and carriers of the human immunodeficiency virus. Among the protozoa that most commonly cause disease in immunocompromised individuals are Toxoplasma gondii, Trypanosoma cruzi, Cryptosporidium parvum, Isospora belli, Cyclospora cayetanensis and microsporidia; the former two cause severe encephalitis and myocarditis, and the others cause gastrointestinal infections. Early diagnosis and prompt institution of specific therapy for each of these organisms are basic measures to decrease morbidity and mortality associated with these infections

Atualizaçäo terapêutica nas parasitoses intestinais no período infantil / Therapeutic review of intestinal parasitoses in childhood

Os autores procedem a uma revisäo minunciosa do tatamento das helmintíases e protozooses intestinais prevalentes na infância, apresentando os mais recentes avanços no campo do diagnóstico e da terapêutica

Opportunistic intestinal protozoal infections in immunocompromised children

One hundred immunocompromised children and 100 house contact controls were chosen for this study. Patients included 52 nephrotic syndrome children receiving corticosteroids for more than one month [age 5.28 +/- 2.32 years], 14 protein-calorie malnutrition [PCM] patients [8 cases of marasmus aged 6 +/- 2.27 months and 6 cases of marasmic kwashiorkor aged 1.39 +/- 0.88 years] and 34 lymphomas patients [22 cases of Hodgkin's disease and 12 cases of non-Hodgkin's lymphoma aged 4.5 +/- 3.54 years]. Examination of concentrated stool was done using iodine stain of fresh mounts and modified Ziehl-Neelsen [cold acid-fast] to fixed smears. T-cell subsets were counted after staining with mouse monoclonal antibodies against CD4 and CD8 labeled with fluorescein. Both nephrotic syndrome and lymphomas groups showed affection of cellular immunity in the form of significant decrease in T-helper and H/S ratio and significant increase in suppressor T-cell subsets. Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum and Blastocystis hominis were the most frequent in patients group and were significantly more prevalent among patients than controls. No significant difference in the prevalence of Entamoeba coli and Chylomastix mesnili between the two groups was observed. C. Parvum infection was strictly confined to groups with T-cell subsets abnormalities [i.e. nephrotic syndrome and lymphomas groups]

Vacunas contra parasitosis humanas / Vaccines again human parasythosis

A pesar del notorio avance en el conocimiento de la respuesta inmunológica que se genera contra protozoarios y helmintos parásitos, así como en la clonación molecular de genes que codifican para las proteínas de esos organismos, las cuales resultan potencialmente protectoras, todavía no se ha logrado la producción de vacunas operacionales contra las enfermedades parasitarias humanas más importantes (leishmaniasis, enfermedad de Chagas, toxoplasmosis, filariasis, triquinelosis, esquistosomiasis y cisticercosis). De hecho, no existe una sola vacuna inocua y eficaz de uso corriente que permita la protección específica de los individuos que viven en zonas endémicas. Las vacunas contra parásitos constituyen una imperiosa necesidad de salud pública, ya que constituyen causas muy importantes de morbilidad en prácticamente todos los países en vías de desarrollo. La complejidad molecular y estructural de los parásitos y de su relación con el hospedero ha dificultado la producción de vacunas equivalentes a las que están en uso contra virus y bacterias. En este capítulo se revisan los avances que se han generado en el conocimiento de la inmunología de algunas parasitosis propias de los seres humanos -que por razones obvias se han analizado con mucho más detalle con el uso de modelos animales y en el desarrollo de varios tipos de vacunas, desde vivas hasta moleculares, que también han siodo evaluadas sólo en el nivel experimental. Por último, en este capítulo se incluye una sección que analiza por qué para algunas parasitosis ha sido (y probablemente será) muy difíicil el desarrollo de vacunas para su control, que sean eficaces y de uso común

Immunodiagnosis in clinical practice.

Although the definitive diagnosis of diseases caused by worms and protozoa depends upon the demonstration of adult parasite or its ovum in excreta, blood and tissue biopsies of the patient, immunological methods can be of help in the identification of associated immunological syndromes, pathogeneses of these infections in man and as a guide to therapy. However, the non-availability of pure antigens is a limiting factor in effective application of these tests. The present paper describes the immunological syndromes associated with these diseases as well as some of the in-use immunodiagnostic tests.