Scielo RSS <![CDATA[Boletín chileno de parasitología]]> http://www.scielo.cl/rss.php?pid=0365-940220000001&lang=es vol. 55 num. 1-2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[Natural reservoirs of Trypanosoma cruzi]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100001&lng=es&nrm=iso&tlng=es <![CDATA[Antihelmínticos como factor de riesgo en la obstrucción intestinal por Ascaris lumbricoides en niños]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100002&lng=es&nrm=iso&tlng=es In a retrospective study the authors analyzed the clinical records of 199 children ages one month to 16 years hospitalized, with the diagnosis of intestinal ascariasis, in the Instituto Nacional de Pediatria of Mexico from 1984 to 1999. The purpose of the study was to evaluate the use of anthelmintics drugs as a risk factor of intestinal obstruction by A. lumbricoides. Two groups were made for the study: Group A (n=66) of children who presented intestinal obstruction, Group B (n=133) children with no complications. A comparative analysis of clinical data of both groups was made by means of chi square with Yates correction and a stratified analysis by means of chi square. Possible confusing elements were overcrowding, age and the use of antiparasitic drugs. The calculus of risk factors for intestinal obstruction by A. lumbricoides was done by means of contingency tables of 2 x 2 and odds ratio with an IC of 95%. The significant risk factors were included in a model of logistics regression with an impact variable consting in the presence or absence of intestinal obstruction in order to establish a multivariate model of predictive risk a level of significance of p < 0.05. Twenty seven patients (40.90%) in group A (n=66) were given anthelmintics medications prior to the intestinal obstruction: mebendazol, 14 (51-85%); two, albedazol (7.40%); eigth, a non-specifed anthelmintic (29-62%). In addition, an anthelmintic medication without a specified time of ingestion: two with mebendazol and one with piperazine (11.3%). In the case of mebendazol, the drug most frequently associated with intestinal obstruction, seven patients received it on the same day of the obstruction; five patients received it between one and seven days prior to the obstruction; two received it seven days prior to the complication. In the control group, only 7% had taken the anthelmintic one to seven days before the diagnosis of uncomplicated intestinal ascariasis diagnosis was made. With the step by step (Backward) logistic regression conditioned by the treatment variable with an anthelmintic, an X² = 38.15 gl, p < 0.000 was obtained for which reason it was considered by A. lumbricoides. Of the probable risk factors analyzed in this study, the only one capable of influencing and predicting the presentation of intestinal obstruction by A. lumbricoides in children, was the prior anthelmintic treatment particulary with mebendazol. <![CDATA[<B>Evaluación de las pérdidas producidas por la hidatidosis y análisis del costo/beneficio de diferentes intervenciones estratégicas de control en la Provincia de Río Negro, Argentina</B>.]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100003&lng=es&nrm=iso&tlng=es Los programas de control de la hidatidosis requieren de la elaboración de ecuaciones costo/beneficio para la justificación técnica del mantenimiento de su fuente de financiamiento. Así, el objetivo del presente trabajo es analizar los costos para los servicios de salud de la Provincia de Río Negro, Argentina, la atención médica de los casos económicamente alternativas futuras en las estrategias de control. Para ello se obtuvo información de casos humanos atendidos en tres hospitales, tratados con métodos quirúrgicos convencionales, con quimioterapia y con PAIR (punción, aspiración, inyección y reaspiración), procediéndose a valorizar las prácticas médicas efectuadas. Se estimaron asimismo costos del programa de control basado en la desparasitación de perros y de programas alternativos basados en diagnóstico masivo en personas mediante ecografía y serología, y tratamientos no convencionales. Se estimmó un costo de tratamiento de US$ 4.511 por paciente, US$ 5.936 en cirugía convencional, US$ 1988 en PAIR y US$ 1.350 en quimioterapia con albendazol. Los costos globales de atención médica para 1997 fueron estimados en US$ 293.215, resultando un 77% inferiores a 1980. Se estimaron los costos operativos del programa tradicional de control en US$ 440000 y uno alternativo basado en diagnóstico y tratamiento en US$ 260.218. Se analizan relaciones costo/beneficio para cada una de las estrategias planteadas. <![CDATA[<I>Estudio comparativo de la sensibilidad y mortalidad de las ninfas III y IV de Triatoma infestans usadas en el xenodiagnóstico de pacientes crónicos.</I>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100004&lng=es&nrm=iso&tlng=es Triatoma infestans nymphs have shown a good sensitivity for detecting Trypanosoma cruzi in the blood stream of infected hosts when are used in the xenodiagnosis (XD). This method, with its natural limitations, using seven nymphs III of T. infestans, has been routinely utilized with satisfactory yield. With the aim of an eventual improving of the yiel of XD (with 7 nymphs), two series of 54 XD boxes each, containing a total of 378 nymphs III and 378 nymphs IV respectively, were applied - one of each during three consecutive days - to nine chronic chagasic patients. Each of the nymphs was weighted before and after the application of the boxes, and the intestinal content of them was examined 30 , 60 and 90 days later. The main comparative results obtained with nymphs III and IV of T. infestans were: blood ingestion 40 versus 107 mg (2.7 higher), positivity of insects 35.8% versus 50.6% (15.8% higher), positivity of XD boxes (7 nymphs each)46.3% versus 55.6% (9.3% higher), and mortality rates 28,6% versus 12.2% (16.4% lower). All these results demonstrate that nymphs IV of T. infestans, because their higher capacity of ingesting blood and higher tolerance to examination manipulations, are more suitable for been used in XD. <![CDATA[Utilidad diagnóstica de ELISA IgG, IgM, IgA y Elisa avidez de IgG en toxoplasmosis reciente y crónica]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100005&lng=es&nrm=iso&tlng=es Toxoplasmosis, a world-wide zoonotic infection, is generally asymptomatic and benign in immunocompetent individuals, but it can be serious in immunodeficiencies particulary in patients with acquired immunodeficiency syndrome and in children infected in utero. So, it is important to dispose methods which permit discriminate between recent and chronic infections. In order to contribute to improve the diagnosis of toxoplasmosis ELISA IgG, IgM, IgA and ELISA IgG avidity were performed in 15 and 24 sera from patients suspected of having acute and chronic infection respectively, according dye test (DT) titres. ELISA IgG was positive in both groups, ELISA IgM was positive in 78.6 and 58.3% respectively, while ELISA IgA was positive in 85.7 and 33.3% of recent and chronic group respectively. In those sera with low IgG avidity ( 18.8%) we found specific IgM in 71.5 and 4.2% and IgA in 78.6 and 0.0% of recent and chronic groups respectively. Parallely, 208 sera samples were clasified according to the results of DT, indirect hemagglutination and complement fixation tests in the following groups: acute (97), intermediate (36), chronic (35) and negative (40). The results were: acute (96.9-64.9-55.6 and 65.9%); intermediate (97.2-63.8-44.4 and 47.2%); chronic (45.7-42.8- 5.7 and 34.3%) for IgG, IgM, IgA and low IgG avidity respectively. The use of both acute markers, IgA and low IgG avidity in the diagnosis of toxoplasmosis is discussed. <![CDATA[Tributo a la memoria del Prof. Dr. Amador Neghme (1912-1987)<A NAME="Sintesis1"></A>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100006&lng=es&nrm=iso&tlng=es Toxoplasmosis, a world-wide zoonotic infection, is generally asymptomatic and benign in immunocompetent individuals, but it can be serious in immunodeficiencies particulary in patients with acquired immunodeficiency syndrome and in children infected in utero. So, it is important to dispose methods which permit discriminate between recent and chronic infections. In order to contribute to improve the diagnosis of toxoplasmosis ELISA IgG, IgM, IgA and ELISA IgG avidity were performed in 15 and 24 sera from patients suspected of having acute and chronic infection respectively, according dye test (DT) titres. ELISA IgG was positive in both groups, ELISA IgM was positive in 78.6 and 58.3% respectively, while ELISA IgA was positive in 85.7 and 33.3% of recent and chronic group respectively. In those sera with low IgG avidity ( 18.8%) we found specific IgM in 71.5 and 4.2% and IgA in 78.6 and 0.0% of recent and chronic groups respectively. Parallely, 208 sera samples were clasified according to the results of DT, indirect hemagglutination and complement fixation tests in the following groups: acute (97), intermediate (36), chronic (35) and negative (40). The results were: acute (96.9-64.9-55.6 and 65.9%); intermediate (97.2-63.8-44.4 and 47.2%); chronic (45.7-42.8- 5.7 and 34.3%) for IgG, IgM, IgA and low IgG avidity respectively. The use of both acute markers, IgA and low IgG avidity in the diagnosis of toxoplasmosis is discussed. <![CDATA[Infestación de los párpados de un niño por Phthirus pubis]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100007&lng=es&nrm=iso&tlng=es A clinical case of Phthirus pubis infestation of the eyelids in an eight -year-old boy is presented. He complained of a bilateral eyelids inflammation for the last two weeks which had not healed with a daily application of a collyrium. Physical examination showed the presence of small dark spheres, of approximately 1 mm, attached to the proximal extreme of the eyelashes. A microscopical examination of these elements permitted to identify adults and eggas of P. pubis. Neither insects nor eggs were found in the scalp of the patient. Treatment consisted in the extraction of the parasite elements by means of a fine forceps after the application of liquid vaseline in the eyelashes. A total of 23 adult insects and 32 eggs was removed. The boy proceeded from a boarding school, - where none of the other 27 children was found infested- and stayed there from Monday to Friday, going home for week ends. It was impossible to contact the mother, the most probable source the patient infestation, for epidemiological and prophylactical purposes. <![CDATA[Comparación de la infección por Trypanosoma cruzi en niños menores de 10 años de la V Región, Chile. 1982-1995]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100008&lng=es&nrm=iso&tlng=es Evaluation of desinsectation programs carried out in the two Health Services from the V Region, was undertaken by comparing serologic prevalences of T. cruzi in age groups exposed to the risk of infection in rural areas during the antivectorial campaign activities. (1982 vs 1995). Thus, were studied 2,193 blood samples from children under 10 years of age, proceeding rfrom six chagasic endemic provinces in which antitriatomic domiciliary insecticide sprayings had been performed. Indirect hemagglutination and ELISA tests were carried out to each of the blood samples. A total de 42 (1.9%) children resulted positive. As in five counties no positive case were detected in the last five years it is possible to assume that vector trasmission of T. cruzi should have been interrupted in them. When comparing prevalences existing in 1982 with the present ones, it is possible to observe a 63.5% of reduction of transmission in the V Region, been this reduction higher in the Aconcagua Health Service with 79.6% and lower in the Viña del Mar - Quillota Health Service with 55.6%. According to these results, comparison of prevalence of T. cruzi infection in children less than 10-year-old in diverse periods, allows evaluate the vectorial control of Triatoma infestans programs <![CDATA[Infección por helmintos parásitos en salmón coho, Oncorhynchus kisutch, durante su retorno al río Simpson, Chile]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100009&lng=es&nrm=iso&tlng=es Between may and july 1994, 17 adult returning salmons, Oncorhynchus kisutch, were collected in the River Simpson, Chile. All fishes showed infection by plerocercoids of Diphyllobothrium sp. in different locations: stomach, spleen, liver, mesenteries and gonads. Infection with larval cestodes of an unidentified species of Phillobothriidae was determined in the intestine of seven (41.2%) salmons and its prevalences of infection showed significant differences between female and male salmons. The 94.4% of total plerocercoids of Diphyllobothrium were isolated from the stomach wall. Prevalence and mean intensity of infection by Diphyllobothrium sp. did not show significant difference between fishes of different sex. <![CDATA[Efectos producidos por Spinitectus jamundensis (Nematoda, Cystidicolidae) en el estómago del sábalo, Prochilodus lineatus (Pisces, Prochilodidae)]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100010&lng=es&nrm=iso&tlng=es The presence of the nematode Spinitectus jamundensis in cardial and pyloric regions of the stomach of Prochilodus lineatus is observed. Samples of the parasitated stomach were analyzed by histological techniques using Hematoxilin-Eosin and Mallory (Azan) Heidenhain's stainnigs. The macroscopical description of the inner surface of the stomach showing damages in the parasites penetration sites, were observed. Histological observations show that the parasite enters the mucous membrane reaching muscular mucous membrane of the cardial region or the epithelial plaits in the pyloric region reaching up to the muscular layer without crossing it. In this way, the parasite reamins confined by a thin layer of connective tissue and in almost direct contact with tissue liquids. Sometimes, in host tissues as responde to the parasite presence, an increased level in the amount of lymphocytes in the surrounding tissues is observed. <![CDATA[Efecto in vitro del suero de la trucha Arco Iris (Oncorhynchus mykiss) sobre metacercarias del género Tylodelphys (Trematoda, Diplostomatidae).]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100011&lng=es&nrm=iso&tlng=es Here, it has been described that normal fresh sera from rainbow trout (Oncorhynchus mykiss) were able to lyse Tylodelphys sp. metacercariae isolated from Galaxias maculatus (Jenyns, 1842) (Teleostei, Galaxiidae) brain. This effect was time dependent, and progressively increased since 1 h up to 18 h incubation. There were oscillations in the ability of different sera samples to lyse these parasites. Similar values were achieved with other salmonid sera, and also with normal human sera pool. The lytic activity was abolished by heat-inactivated sera, by zymosan treatment and by incubation in the presence of EDTA. However, the mean values obtained in the presence of EGTA-Mg++ did not significantly differ from those found with sera as a source of complement. The results of this study suggested the role of complement alternative pathway on Tylodephys sp. in vitro lysis, under our experimental conditions. <![CDATA[Nota sobre Dujardinascaris cybii Arya and Johnson, 1978 (Nematoda: Heterocheilidae) de un nuevo huésped, Mugil cephalus (Linnaeus)]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-94022000000100012&lng=es&nrm=iso&tlng=es D. cybii fue obtenido del intestino de M. cephalus, pez de agua dulce, constituyendo el registro de un nuevo huésped. Papilas caudales invisibles en la especie descrita vs 13 pares de papilas caudales sésiles en descripción original.