Illusory parasitosis, better known as delusional parasitosis, is a neuropsychiatric syndrome in which patients have the belief of suffering a parasitic disease, that can not be demonstrated after an exhaustive medical study. These patients are characterized by being polyconsultants in different medical specialties and, many of them, have antecedents of psychiatric disorders, some of them undiagnosed. Knowing the existence of the clinical picture, diagnosing early and empathizing with the patient, could give to clinician some clues for a timely and assertive psychiatric referral, and improve patient adherence to the proposed treatment.

La parasitosis ilusoria, más conocida como delusión parasitaria, es un síndrome neuropsiquiátrico donde los pacientes tienen el convencimiento de padecer una infestación parasitaria, que no puede ser demostrada tras un exhaustivo estudio médico. Estos pacientes se caracterizan por ser policonsultantes en distintas especialidades médicas y, muchos de ellos, poseen antecedentes de trastornos psiquiátricos, algunos de ellos no diagnosticados. Conocer la existencia del cuadro, diagnosticar precozmente y empatizar con el paciente, pueden dar al médico clínico algunas claves para una derivación psiquiátrica oportuna y asertiva, y mejorar la adherencia del paciente al tratamiento propuesto. Se presentan cuatro casos clínicos que consultaron por esta extraña condición.

Human fascioliasis is a parasitic zoonosis that affects the liver of human and herbivorous animals. In chronic cases, its diagnosis is confirmed by direct visualization of parasitic eggs in stool examination, by positive testing for Fasciola hepatica antigens in stools, or by direct observation of parasites by endoscopic retrograde cholangiography or surgery. In acute cases, serological reactions as immunoblothing or detection of parasite antigens in the blood are useful. The treatment of choice is triclabendazole. However, parasite resistance in animals, as well as in man, has been reported to this drug. We report four patients in whom the parasitic infection persisted despite a course of treatment with triclabendazole.

Divers inquires established by chagasic patients in relation to its clinical condition, motivated to a group of parasitologists to design an assistance educative programme. 72 volunteer patients participated, 32 men and 40 women from the high and low chagasic endemic zones of Chile. The educative methodology basically consist in the application of a diagnosis and acquired knowledge tests; theorical sessions of six relationated tematics subjects, tutorial practical activities; use of audiovisual and printed material, personal diligence by a parasitological doctor (after the educative assistance and with the serological, electrocardiographical and parasitological antecedents determinated previously) and evaluation of the educative activity by the patients. A greater previous and acquired knowledge was observed in chronic chagasics patients from endemic zones. All of them demonstrated a high degree of interest and actively participated in the programmed activities. The used methodology, the tutorial work of small groups and the individual attention-orientator by the parasitological doctor, facilitated the teaching-learning process. It is concludes that the educative assistance answer many of the inquires in relation to the disease, allows the patient to recognize the role as protagonist of his own comfort and transforms him in an efficient agent to control Chagas disease

Las diversas inquietudes planteadas por pacientes chagásicos crónicos en relación a su condición clínica, motivaron a un grupo de parasitólogos a diseñar un programa de intervención educativa. Participaron en forma voluntaria 72 pacientes, 32 hombres y 40 mujeres, procedentes de zona de alta y baja endemia chagásica de Chile. La metodología docente consistió fundamentalmente en: aplicación de test diagnóstico y de conocimientos adquiridos; sesiones teóricas que abordaron seis temáticas relacionadas; actividades prácticas tutoriales; utilización de material audiovisual e impreso; atención personalizada por médico parasitólogo (posterior a la intervención educativa y con los antecedentes serológicos, electrocardiográficos y parasitológicos previamente determinados) y evaluación de la actividad educativa por parte de los pacientes. Un mayor conocimiento previo y adquirido se observó en chagásicos crónicos procedentes de zonas endémicas. Todos demos-traron un alto grado de interés y participaron activamente de las actividades programadas. La metodología utilizada, el trabajo tutorial de pequeño grupo y la atención-orientación individual por parte del médico parasitólogo, facilitaron el proceso de enseñanza-aprendizaje. Se concluye que la intervención educativa responde a muchas de las interrogantes respecto de la afección, permite al paciente reconocer el rol que le cabe como protagonista de su propio bienestar y lo transforma en un eficaz agente en el control de la enfermedad de Chagas

Entre novembro de 2001 e dezembro de 2002, 600 amostras de fezes de cão foram coletadas nas principais praças e parques públicos de 13 cidades do Chile, localizadas nas regiões norte ao estremo sul da nação. No laboratório, as amostras foram processadas mediante os métodos de sedimentação por centrifugação e de Harada-Mori. Ovos de Toxocara canis foram encontrados em 12 cidades em freqüências que variaram entre 1,9 a 12,5% por cidade, com média de 5,2%. Sete por cento das amostras apresentaram ovos e 9,5% larvas rabditóides ou filarióides de Ancylostomatidae. Strongyloides stercoralis não foi encontrado nas amostras estudadas. Praças e parques públicos do Chile apresentam riscos potenciais para aquisição de larva migrans visceral, ocular ou cutânea.

Between November 2001 and December 2002, 600 dog fecal samples were collected in main squares and public parks of 13 cities in Chile, from the extreme north to the extreme south of the country. The samples were processed in the laboratory by centrifugal sedimentation and the Harada-Mori methods. T. canis eggs were found in 12 cities. Detection rates ranged from 1.9 to 12.5% with an average of 5.2%. Seven percent of the samples had eggs and 9.5% had rhabditoid and/or filariform larvae of Ancylostomatidae. Strongyloides stercoralis were not found. Squares and public parks in Chile pose a potential risk of exposure to visceral, ocular, and/or cutaneous larva migrans syndromes.

Entre novembro de 2001 e dezembro de 2002, 600 amostras de fezes de cão foram coletadas nas principais praças e parques públicos de 13 cidades do Chile, localizadas nas regiões norte ao estremo sul da nação. No laboratório, as amostras foram processadas mediante os métodos de sedimentação por centrifugação e de Harada-Mori. Ovos de Toxocara canis foram encontrados em 12 cidades em freqüências que variaram entre 1,9 a 12,5% por cidade, com média de 5,2%. Sete por cento das amostras apresentaram ovos e 9,5% larvas rabditóides ou filarióides de Ancylostomatidae. Strongyloides stercoralis não foi encontrado nas amostras estudadas. Praças e parques públicos do Chile apresentam riscos potenciais para aquisição de larva migrans visceral, ocular ou cutânea.

Between November 2001 and December 2002, 600 dog fecal samples were collected in main squares and public parks of 13 cities in Chile, from the extreme north to the extreme south of the country. The samples were processed in the laboratory by centrifugal sedimentation and the Harada-Mori methods. T. canis eggs were found in 12 cities. Detection rates ranged from 1.9 to 12.5% with an average of 5.2%. Seven percent of the samples had eggs and 9.5% had rhabditoid and/or filariform larvae of Ancylostomatidae. Strongyloides stercoralis were not found. Squares and public parks in Chile pose a potential risk of exposure to visceral, ocular, and/or cutaneous larva migrans syndromes.

A familiar outbrake of strongyloidosis affected peruvian immigrants who had arrived Chile in november 2001 is reported. In march 2002, Strongyloides stercoralis infection of the index individual was confirmed by the Basic-Clinical Laboratory of Parasitology of the Faculty of Medicine of the University of Chile, in Santiago, Chile. At the Roberto del Río Pediatric Hospital, a 11 years old girl presenting juvenil rheumatoid arthritis and mild abdominal distress was studied. A serial of three stool samples was collected and procesed by ether-centrifugal concentration technique. A plentiful quantity of rhabditoid larvae of S. stercoralis was observed. To detect larvae in the faeces and specific serum antibodies against S. stercoralis by means of ELISA her parents and sister were studied. The mother of the index case and her sister were positive in both test. The father was not infected. The three positive cases were treated with Ivermectine. A control study performed one year later demonstrated a positive ELISA test only in the sister

Se presenta un brote familiar de stron-gyloidosis que afectó a inmigrantes peruanos que habían llegado a Chile en noviembre del año 2001. En marzo del 2002, se confirmó en el Laboratorio de Parasitología Básico-Clínico de la Facultad de Medicina de la Universidad de Chile que el caso índice presentaba infección por Strongyloides stercoralis. Correspondía a una menor de 11 años que estaba siendo estudiada en el Hospital Roberto del Río por artritis reumatoide juvenil. Además de esta patología la niña refería leves molestias abdominales, siendo derivada a nuestra unidad, donde se le efectuó un examen parasitológico seriado de deposiciones (EPSD), observándose abundantes larvas rabditoides de S. stercoralis, por lo cual se procedió a estudiar al grupo familiar integrado por los padres y una hermana. A todos ellos se les efectuó EPSD e inmunodiagnóstico mediante ELISA para detectar anticuerpos anti S.stercoralis. Resultaron positivos para ambos exámenes la madre y las dos hijas. El padre fue negativo. Se decidió tratar con ivermectina y controlar los resultados del tratamiento anti-parasitario al grupo familiar al cabo de un año. Después de ese periodo permanecía positiva serológicamente, solamente la hermana del caso índice debido a que no ingirió los medicamentos de la manera indicada

In may 2003 an epidemiologic-parasitological survey was carried out in 206 pre-school and school-children from San Vicente de Lo Arcaya School in Colina, a semi-rural county of the Santiago Province in the Metropolitan Region of Chile.The most frequent parasitic elements were: Blastocystis hominis - in men and women respectively - 38.8% and 44.4%, Giardia intestinalis with 9.5% and 16.2% and Enterobius vermicularis with 12.9% and 10.0%. It is notewortly that the infected children were asymptomatic Cryptosporidium parvum was not observed and an ELISA test for Strongyloides stercoralis infections was positive in one children.This study confirms that intestinal parasitic infections in children remain with a high prevalence in Chile.

En mayo de 2003 se efectuó una encuesta epidemio-parasitológica en pre-escolares y escolares de la Escuela San Vicente de Lo Arcaya de Colina, comuna semirural de la Provincia de Santiago ubicada en la Región Metropolitana de Chile. Hay que destacar que los niños estudiados eran asintomáticos. Los elementos parasitarios más frecuentemente encontrados fueron: Blastocystis hominis - en hombre y mujeres respectivamente - 38,8% y 44,4%, Giardia intestinalis con 9,5% y 16,2% y Enterobius vermicularis con 12,9% y 10,0%. Cryptosporidium parvum no fue encontrado y ELISA para Strongyloides stercoralis resultó positiva en un niño.

Most of cases of visceral larva migrans syndrome are caused by Toxocara canis larvae. Man acquires the infection by accidental ingestion of ripe eggs of the helminth. In order to find out the frequency of the presence of Toxocara sp. eggs in dog fecal specimens from public places of Santiago city in 1999 july-september a study was carried out in 84 squares and 12 parks from 32 counties. Three fecal samples were collected in each of these places, making a total of 288. Each sample was processed according to a modified Telemann method and three smears of each were microcopically examined. Toxocara sp. eggs were found in 39 (13.5%) fecal specimens. In 28/84 (33.3%) squares and in 8/12 (66.7%) parks these eggs were detected. These results make necessary the control of dogs and cats populations with the aim of reduce the presence of animals without responsible owners. It should be advisable to prevent dogs and cats defecation in public areas grounds, trying to exclude these animals from recreation areas.

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.