Scielo RSS <![CDATA[Parasitología al día]]> vol. 23 num. 3-4 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<I>Hemolytic activity of fresh isolates and clones of Trichomonas gallinae</I>]]> In in vitro assay the hemolytic activity of live isolates and clones of Trichomonas gallinae was investigated. The fresh isolates and clones were tested against human erythrocytes of groups A, B, AB, and O, and against erythrocytes of six adult animals of different species (rabbit, rat, chicken, horse, bovine, and sheep). Results showed that each of the isolates and clones tested lysed all human blood groups, as well as rabbit, rat, chicken, horse, bovine and sheep erythrocytes. No hemolysin released by the parasites could be identified. Parasite culture supernatants of hemolysis assays, tested in the presence of human erythrocytes did not induce any hemolytic activity. Trichomonads culture supernatants from 18, 24, and 48 hr extracts of sonicated parasites or cold killed organisms tested with human erythrocytes did not exhibit hemolysis. Although an hemolytic activity of T. gallinae was clearly demonstrated, a relationship between hemolysis and cell pathogenicity is not yet clearly established. <![CDATA[<I>The distribution of Ascaris lumbricoides infection in humans from a rural community in Venezuela</I>]]> A total of 337 persons (86.8%) were examined by faecal egg count and worm burden by counting expelled parasites following anthelmintic treatment (Oxantel Pyrantel PamoateR) in order to study the prevalence and distribution of Ascaris lumbricoides in the human population of a rural locality from Venezuela. The number of positive diagnosis of A. lumbricoides infection by worm collection was higher than by eggs determination and the degree of infection determined by egg counts resulted well associated with the worm burden (P &lt; 0.001) and so it may used with some confidence. The prevalence and intensity of infection were similar in both sexes. In relation to the age, the highest values for prevalence (P &lt; 0.05), relative risk (P &lt; 0.01) and intensity of infection (P &lt; 0.02) were observed in the 5 to 9 year old children. Within the population, few individual (20.19%) harboured more than 6 roundworms and many of the hosts (38.3%) had only a few (1 to 5 worms) or none worm (41.53%). <![CDATA[<I>Ação dos fungos Beauveria bassiana (Balsamo) Vuillemin, 1912 e Metarhizium anisopliae (Metschnikoff, 1879) Sorokin, 1883 sobre larvas do carrapato Anocentor nitens (Acari: Ixodidae)</I>]]> The pathogenicity of isolates Ma959, MaE9, Ma319 from Metarhizium anisopliae and isolate Bb747 from Beauveria bassiana was evaluated using Anocentor nitens larvae under controlled conditions. Four suspensions with different concentrations (108, 107, 106 and 105 conidia/ml) were tested for evaluating the percentage of larvae mortality ten days after the infection and the probit analysis was realized. The mortality average of larvae in treated groups with the isolate Ma959 alternate between 80.8% and 10.2%. The use of isolate Ma319 showed almost 100% of mortality for the 108 conidia/ml concentration. The isolate MaE9 showed the best results of mortality in 108 and 107 concentration. The mortality of the groups treated with Bb747 alternate between 3.6% (105 conidia/ml) to 97.4% (108 conidia/ml). The LC 50 were 1.6 x 106; 1.2 x 106; 1.6 x 107 e 1.8 x 106 for the isolates Ma319, MaE9, Ma959 e Bb747, respectively. The results reveal a susceptibility of Anocentor nitens larvae to these fungus and prove their potential use in integrate control programs.<hr/>A patogenicidade in vitro dos isolados Ma959, MaE9 e Ma319 do fungo M. anisopliae e do isolado Bb747 de B. bassiana foi avaliada em larvas do carrapato A. nitens mantidas em temperatura controlada. Quatro suspensões com diferentes concentrações (105, 106, 107 e 108 conídios/ml) de cada isolado foram testadas para avaliar o percentual de mortalidade das larvas após 10 dias da infecção calculando-se as concentrações letais 50 e 90. A média de mortalidade nos grupos tratados com o isolado Ma959 variou entre 81% à 10%. O uso do isolado Ma319 revelou uma mortalidade de quase 100% das larvas na concentração 108 conídios/ml. Os testes realizados com o isolado Ma E9 revelaram uma maior mortalidade de larvas nas concentrações 108 e 107 conídios /ml. A média de mortalidade nos grupos tratados com o isolado Bb747 variou entre 4% (105 conídios/ml) à 97% (108 conídios/ml). As DL 50 foram 1,6 x 106; 1,2 x 106; 1,6 x 107 e 1.8 x 106 para Ma319, MaE9, Ma959 e Bb747, respectivamente. Os resultados obtidos demonstram a susceptibilidade das larvas de A. nitens frente à estes fungos, comprovando seu potencial uso em programas integrados de controle. <![CDATA[PLASMATIC EXOERYTHROCYTIC MEROGONY IN <I>Plasmodium (Novyella) juxtanucleare</I> (APICOMPLEXA: PLASMODIIDAE)]]> A research about plasmatic exoerythrocytic meronts of the Plasmodium juxtanucleare in crossbred fowls from Seropédica municipality, Rio de Janeiro state, Brazil, was made. The hemoscopical exam of fowls with high erythrocytic parasitaemia (&gt;10%) showed free exoerythrocytic meronts with an average size of 7.492 ± 2.308 X 5.926 ± 2.048 µm; containig about 15 ± 16.92 merozoites. The meronts showed to be pleomorphic characteristics from spherical to oval with merozoites of basophilic nucleus. They also showed torn meronts with free merozoites. All the observations reported and discussed about this subject make us conclude that P. juxtanucleare studied strain has a paraerythrocytic merogony. It suggests that P. juxtanucleare is an evolutionary plasmodia species intermediate between the plasmodia of reptiles and the plasmodia of mammals.<hr/>Se realizó un estudio de los esquizontes exoeritrocíticos plasmáticos de Plasmodium juxtanucleare en gallinas sin raza definida, provenientes del município de Seropédica, estado de Rio de Janeiro, Brasil. Al examen sanguíneo se pudo observar en aves con alto índice de parasitémia eritrocítica (&gt; 10%) formas esquizogónicas exoeritrocíticas libres, con un tamaño promedio de 7,492 ± 2,308 X 5,926 ± 2,048 µm; conteniendo una média de 15 ± 16,92 merozoítas. Estos esquizontes se presentaron con características pleomórficas de redondeado a oval, con merozoítos de núcleo basofílico. Se observó también, formas de esquizontes rotos con merozoítas libres. Estas y otras observaciones, reportadas y discutidas, hacen inferir que la cepa de P. juxtanucleare estudiada, realiza un ciclo paraeritrocítico. Se sugiere que P. juxtanucleare es una espécie de plasmodio, evolutivamente, <A NAME="BM_"></A>intermediário entre los plasmodios de reptiles y los de mamíferos . <![CDATA[<I>Strongyloides stercoralis</I> INFECTION IN ALCOHOLIC PATIENTS]]> The infection with Strongyloides stercoralis in 106 chronic alcoholic patients W8S evaluated, using agar plate culture (APC),Baermann method, and microscopic observation of direct smear of feces. Baermann method detected 6 (5.7%) cases: whereas by APC one case W8S not diagnosed (sensitivity of 83.3%), and only 2 were visualized by direct smear (sensitivity of 33.3%). Other intestinal parasites diagnosed were Endolimax nana (16%), Giardia 1amblia (7.3), Entamoeba coli (6.6%), Entamoeba histolytica (4.7%), hookworm (0.9%), Hymenolepis nana (0.9%), and Entamoeba hartmanni (0.9%). The overall prevalence of intestinal parasites in the patients studied was 30%. This value is relatively low. but it is in accordance with the national prevalence of 21% or less than 5% if only helminths are considerd. lt is important the comparison of hookworm and S. stercoralis infection in alcoholic patients, since both parasites have similar infection mechanisms, and our data showed a higher prevalence for the latter, that denote possible increasing risk for this infection.<hr/>Se evaluó la infección con Strongyloides stercoralis en 106 pacientes alcohólicos crónicos, usando el método de Baermann, el cultivo en plato de agar (CPA) y la observación microscópica de frotis de heces. El parásito fue observado en 6 (5,7%) casos. Todos diagnosticados por Baermann, 5 por CPA (sensibilidad = 83,3%), y solo 2 por el frotis directo (sensibilidad = 33,3%). Otros parásitos intestinales diagnosticados fueron Endolimax nana (16%), Giardia lamblia (7,3%), Entamoeba coli (6,6%), Entamoeba histolytica (4,7%), uncinarias (0,9%), Hymenolepis nana (0,9%) y Entamoeba hartmanni (0,9%). La prevalencia global de parásitos intestinales en los pacientes estudiados fue del 30%, un valor relativamente bajo; pero en concordancia con la prevalencia a nivelnacional que fue 21% o menor al 5% si sólo se consideran los helmintos intestinales. Además, es importante la comparación de las infecciones por uncinarias y S. stercoralis en pacientes alcohólicos, porque ambos parásitos tienen mecanismos de infección similares; pero nuestros datos muestran una mayor prevalencia para el último, lo que denota un posible incremento en el riesgo para esta infección en pacientes alcohólicos. <![CDATA[PARASITES OF THE COTTON RAT <I>Sigmodon hispidus </I>FROM ALAJUELA, COSTA RICA]]> Cotton rats (Sigmodon hispidus) from a pineapple plantation in Costa Rica were studied searching for parasites. Seventy four animals were trapped, sex and pregnant condition determined and dissected to study all their organs. The presence of nematodes and protozoa was determined and classification of these parasites was performed. Eimeria oocysts were kept in presence of 2.5% potasium dichromate for sporocyst and sporozoites development. Most of the organisms were intestinal parasites and all the rats have at least one nematode, wihle 57.4% presented some protozoa. The parasites found were: Longistriata adunca (95.9%), Angiostronylus costaricensis (42.3%), Eimeria sigmodontis (28.4%), Trichomonas sp. (23.0%), E. tuskegeensis (10.8%), E. roperi (5.4%) y E. webbae (1.4%). There was a significative difference between protozoa infection in pregnant female rats (60.5%) as compared with non-pregnant animals. This study is a contrtibution to the knowledge of the parasitological fauna of S. hispidus in Costa rica.<hr/>El interés de los investigadores por el uso del roedor Sigmodon hispidus como modelo experimental ha incrementado en los últimos años. Por ello y dado el poco conocimiento de las poblaciones de parásitos de las ratas de la región estudiada, se analizó la prevalencia de endoparásitos en ratas procedentes de zona de cultivo de piña de Alajuela. A 74 ratas capturadas se les registró el sexo, y a las hembras se les determinó su estado de gravidez. Se realizó una disección completa de los animales con revisión meticulosa de todos los órganos. Los contenidos intestinales fueron analizados al fresco y a los que resultaron positivos por ooquistes de Eimeria sp., fueron colocados en una solución de dicromato de potasio al 2,5% para la maduración de los ooquistes. El 51,2% de las ratas estaban parasitadas por protozoarios y el 100% por helmintos, (nemátodos). Las prevalencias encontradas fueron: Longistriata sp, 95,9%, Angiostrongylus costaricensis 42,3%; Eimeria sigmodontis 28,4%; Trichomonas sp 23,0%; Eimeria tuskegeensis 10,8%; Eimeria roperi 5,4% y Eimeria webbae 1,4%. La prevalencia de protozoarios fue menor de la que ha sido informada en estudios anteriores, posiblemente porque la zona analizadas está en vías de desarrollo urbano-industrial. La prevalencia de A. costaricensis, agente etiológico de la angiostrongiliasis abdominal y de Longistriata sp fue muy elevada. Se notó una mayor prevalencia de protozoarios en hembras no embarazadas (60,5%) que en las embarazadas lo cual pareciera indicar una mayor resistencia de las madres ante estos parásitos en los períodos de desarrollo del feto. <![CDATA[TREATMENT OF CHAGAS DISEASES]]> Up to day, it is accepted that human Chagas disease must be treated in any of its evolution periods , with the only exception of the chronical terminal phase In the acute clinical period infection of less than two months and in the biological period with demonstration of parasites in fresh blood smears, stick drop, with positive conventional serology and positive IgM. Treatment is with nifurtimox (NF) 8-10 mg/kg per day in adults and 15 mg/kg per day in children for 60-90 days. The dosis is given in three daily intakes. The clinical and serology cure 60%. In Brazil where this drug is not used benznidazol (BNZ) is prescribed at dosis of 5 mg/kg per day for adults and 5-10 mg/kg per day in children during 60 days. In congenital infection therapy must be applied as soon as the dignosis is confirmed by clinic and demonstration of parasites at fresh blood, smear microstraut, etc. In the new born often the dignosis is done when he has the chronic period of the infection by persistence of the conventional serology for more than 6 months. In these cases a clinical, serological and parasitological follow up have to be performed. Accidental infections must receive treatment during 10 days. In organ transplant with a chagasic recipient or donor treatment is indicated with NF or BNZ in the same dosis and time as was written above. Reactivations in chronic cases, example persons who acquire AIDS, or present a depresion of cellular immunity like leukemia, Hodgkin, etc. must be treated as acute cases with NF or BNZ for 5 or more months. In these cases prevention is the best to perform : Chagas serology to patiens with AIDS, etc. In the chronic period there is consensus in the treatment due that either in the indeterminate or in the recent chronic period therapy has compliance since there are always tissue parasites demonstrated by PCR.In children less than 10 years of age with chronic recent infection, treatment with NF during 60 días or BNZ at dosis of 5 mg/kg per day in children with the indeterminate phase has given good results. In adults itraconazol at dosis of 6 mg/kg per day during 120 days, in twc daily intake a 60% of cure is obtained. With BNZ at a dosis of 5 mg/kg per day during 30 days a decrease of the new electrocardiographic in chronic cardiophats has been observed. It is important to point out that generally in the chronic period there is no negativation of conventional serology and the criteria of cure is based in others parameters , such as negativization of xenodiagnosis or hemocultures, change positive PCR to negative.<hr/>En la actualidad se acepta que la enfermedad de Chagas humana debe ser tratada en cualquier período de su evolución con la única excepción del período crónico terminal. En el período agudo clínico, infección de menos de 2 meses así como en el biológico: pesquisa de parásitos al fresco, frotis, gota gruesa y con serología convencional positiva e IgM(+). El ideal de tratamiento es con nifurtimox (NF) 8-10 mg/kg día en adultos y 15 mg/kg día en niños por 60-90 días. La dosis se reparte en tres tomas. La curación clínica y serológica es de un 60%. En Brasil donde no se utiliza este fármaco se trata con benznidazol (BNZ) 5 mg/kg día (adultos) y 5-10mg/kg día en niños por 60 días. En las infecciones congénitas la terapia debe ser precoz en cuanto se realice el diagnóstico por clínica y pesquisa del parásito al fresco, frotis, microstraut etc. Muchas veces el diagnóstico se efectúa por persistencia de la serología por más de 6 meses y el recién nacido ya esta en etapa crónica de la infección. Es necesario efectuar seguimiento clínico serológico y parasitológico de los casos. Las infecciones accidentales deben ser tratadas por 10 días. En los trasplantes de órganos en que el receptor o dador es chagásico se debe indicar terapia con NF o BNZ a igual dosis y tiempo que la señalada anteriormente. Las reactivaciones en los casos crónicos ejem: que adquieren un SIDA o que presentan depresiones del sistema de inmunidad celular como leucemias, Hodgkin, etc se deben tratar como cuadros agudos con NF ó BNZ por periodos prolongados de 5 ó más meses. En estos casos obviamente la prevención es lo ideal: hacer serología para Chagas a los pacientes con SIDA, etc. En el período crónico hay consenso en el tratamiento debido a que tanto en la forma indeterminada como en el período crónico inicial la terapia tiene rendimiento ya que siempre hay parásitos tisulares demostrados por PCR aunque el microscopio óptico no los visualice. En niños menores de 10 años con infección crónica reciente el NF durante 60 días ha dado buenos resultados al igual que en el BNZ a dosis de 5mg/kg día por 60 días en niños de 6-12 años con la forma indeterminada. En adultos el itraconazol a dosis de 6 mg/kg al día por 120 días, repartido en dos dosis ha permitido una curación del 60%. El BNZ a dosis de 5mg/kg día por 30 días ha demostrado disminuir las alteraciones electrocardiográ-ficas nuevas de los cardiopatas crónicos. Es importante señalar que por lo general en el período crónico no hay negativización de la serología convencional y el criterio de curación se debe basar en dos o más de los siguientes parametros, que se deben mantener así por varios años y siempre que no exista posibilidad de reinfección: 1) Negativización del xenodiagnóstico 2) Negativización de los hemocultivos 3) Viraje del PCR de (+) a (-) 4) Viraje de los anticuerpos líticos de (+) a (-) 5) Mejoría clínica y del ECG. Especialmente en cardiopatías recientes. <![CDATA[TOXOCAROSIS IN CHILE: CLINICAL SERIE IN A PEDIATRIC AMBULATORY CENTER]]> Between january and august 1997 a study of toxocarosis by ELISA was done in 364 children which had a hemogram done. Twenty four of them had eosinophilia (range: 400-9135 eos/mm) (6.6%) and 8 patients from this group (8/24) showed a seropositive reaction against somatic antigens of Toxocara. <![CDATA[COMPARISON BETWEEN THE MC MASTER AND VISSER FILTER TECHNIQUES FOR COUNTING EGGS OF GASTRO INTESTINAL HELMINTHS OF HORSES]]> Fifty horse faeces samples were analysed five times by each proposed technique. After being processed, the results showed that the Visser Filter is more indicated for the counting of eggs of horses' gastrointestinal helminths.<hr/>RESUMO Foram analisadas fezes de 50 eqüinos adultos segundo cada técnica proposta. Para cada animal foram feitas 5 repetições de exames em ambas as técnicas. Após processadas, os resultados demonstraram que a técnica do Filtro de Visser é a mais indicada para a contagem de ovos de helmintos de eqüinos. <![CDATA[<I>Modification and adaptation in semi-defined media for cultivation of flagellate Tetratrichomonas didelphidis (Trichomonadidae trichomonadinae) from the Didelphis marsupialis</I>]]> Tetratrichomonas didelphidis (Hegner and Ratcliffe, 1927) Andersen and Reilly, 1965 is a flagellate protozoan from the intestine, cecum, and colon of Didelphis marsupialis Linnaeus, 1758. The parasite was found and isolated in the rectal glands in Pavlova starch-containing media in Florianópolis, SC, Brasil from D. <![CDATA[OCCURRENCE OF BOVINE FASCIOLOSIS IN ITAGUAL, RIO DE JANEIRO, BRAZIL]]> The registration of the fasciolosis was accomplished in Itaguai, Rio de Janeiro, Brazil. The verification of the presence was accomplished through coprologics and clinical exams and necropsias in bovine. The installation of the natural focus was verified through the encounter of the larval forms in Lymnaea columella captured in the farm. This registration, the first in the municipal district, is considered epidemiologically important due to the factors imposed by the socioeconomic conditions presented in the area in study.<hr/>Foi realizado o registro de ocorrencia de foco natural de fasciolose em Itaguai, Rio de Janeiro, Brasil. A constatcao de presencia foi realizada através de exames clínicos, coprológicos e de necrópsias realizadas em bovinos. A instalacao do foco natural foi constatada através do encontro das formas larvares em moluscos da espécie Lymnaea columella capturados na fazenda. Este registro, o primeiro no município, é considerado epidemiológicamente importante devido aos fatores impostos pelas condicoes socio-economicos apresentadas na área em estudo <![CDATA[USE OF A QUESTIONNAIRE TO IDENTIFY BLOOD DONORS OF NONENDEMIC AREA, POTENTIALY INFECT WITH Trypanosoma cruzi]]> Large numbers of immigrants from endemic areas for Chagas' disease resided in Maule Region and transmission can occur by blood important evaluated the usefulness of a questionnaire for identifying Trypanosoma cruzi infected blood donors in nonendemic area. In this work participate blood donors of 7 hospitals of the Region. During the 6-month period, 1.581 blood donors were asked and their samples were analysed for T. cruzi antibodies.The effectiveness of the questionnaire was evaluated by comparing donor's answers about their risk for Chagas' disease with the result of testing with an enzyme-linked immunosorbent assay. Positives samples were confirm by: indirect immunofluorescence, and polymerase chain reaction. Only one donor was positive to Chagas' disease. This donors reported no risk factors. Therefore blood donors seropositive for T. cruzi are presente in donors population of nonendemic area without the usual identifiable risk factors<hr/>Un número importante de inmigrantes provenientes de áreas endémicas para enfermedad de Chagas viven en la VII Región. Dado que una de las formas de transmisión del Chagas es por transfusión sanguínea, es importante evaluar , en zonas no endémicas, la utilidad de una encuesta de predonación para identificar donantes de sangre infectados con Trypanosoma cruzi. En este trabajo participaron 7 hospitales de la Región, durante un período de 6 meses, 1.581 donantes de sangre fueron encuestados y sus sueros analizados para detectar la presencia de anticuerpos anti-T.cruzi. La efectividad del cuestionario empleado fue evaluada, correlacionando las respuestas a las diferentes preguntas sobre la enfermedad, con el resultado del ensayo inmunoabsorbente ligado a enzima. Las muestras positivas fueron confirmadas por: inmunofluorescencia indirecta y reacción en cadena de la polimerasa. Solamente un donante fue positivo para enfermedad de Chagas. Este dador no reportó factores de riesgo. Por lo que, donantes de sangre seropositivos y parasitémicos para T. cruzi, están presentes en la población de donantes de sangre de zonas no endémicas, sin tener los usuales factores de riesgo.