Praziquantel in the treatment of Hymenolepis nana infections in children.

One hundred and fifty-five Hymenolepis nana-infected children were treated with a single oral dose of praziquantel, a new and effective isochinolinpyrazin compound with a broad spectrum of activity against cestodes. The children were distributed in three groups which received different dosages of the drug. Parasitological cures were obtained in 64 (98.5%) of 65 children given 25 mg/kg body weight, in 61 (93.8%) of 65 given 15 mg/kg, and in 19 (76.0%) of 25 given 10 mg/kg. Drug tolerance was good, and no clinical side effects were observed. A series of blood and urine tests performed before and after treatment in 30 patients who received 25 mg/kg remained within normal values.

Evaluation of a Triatoma infestans elimination program by the decrease of Trypanosoma cruzi infection frequency in children younger than 10 years, Chile, 1991-1998.

Chagas disease is widespread in Chile, distributed in rural and periurban areas in the 7 most northern regions of the country. The principal vector of Trypanosoma cruzi is Triatoma infestans. The interruption of the domestic cycle of transmission of T. cruzi has been attempted by health education, human housing improving, and elimination of the vector by means of systematic insecticide spraying of human dwellings. Spraying with insecticides has been supported by Chile's health authorities and has been carried out for the last 12 years. A total of 13,280 children (aged up to 10 years) were randomly selected from 47 counties in the area of Chile endemic for Chagas disease, and blood samples were collected to determine the levels of antibodies to T. cruzi by indirect hemagglutination and enzyme-linked immunosorbent assay tests. The results of the tests were analyzed to determine the changes that occurred after 12 years of insecticide spraying of dwellings to eliminate T. infestans infestation. A total of 142 (1.1%) samples of children showed antibodies to T. cruzi. This rate is significantly lower than the data generated in similar studies conducted in 1982-1985. The following reduction in prevalence rates were observed in each of the 7 endemic regions of the country: region I, 5.5-0.3%; region II, 6.6-0.3%; region III, 9.8-1.0%; region IV, 7.2-2.0%; region V, 5.2-1.9%, Metropolitan region, 1.4-0.6%; and region VI, 1.4-0.4%. Serovigilance of T. cruzi antibodies level represents a novel approach that may allow the evaluation of the impact of the vector elimination program. The results identify regions that need to strengthen the efforts to reduce the insect infestation of dwellings.

Effect of venom gland extracts of the South American brown spider, Loxosceles laeta, on in vitro protein synthesis.

There was no effect of the venom extract on incorporation of phenylalanine into protein from phenylalanyl-tRNA. In contrast, the esterification of amino acids with tRNA was inhibited by the venom extracts in a dose-dependent manner, with an apparent preservation of the covalent structure of aminoacyl-tRNA.

International Commission on Trichinellosis: recommendations on methods for the control of Trichinella in domestic and wild animals intended for human consumption.

This document provides a uniform set of recommendations for the control of Trichinella at all levels (on the farm, at slaughter and in processed meats). These recommendations are based on the best scientific information available and represent the official position of the International Commission on Trichinellosis regarding acceptable control methods. These recommendations are subject to change as new scientific information becomes available.

[Loxoscelism in Chile. Epidemiologic, clinical and experimental studies]. / Loxoscelismo en Chile. Estudios epidemiológicos, clínicos y experimentales.

A panoramic sight of epidemiological, clinical and experimental studies, referring to Loxosceles laeta and loxoscelism, carried out in 1955-1988, in Santiago, Chile is presented. Two-hundred and sixteen cases of loxoscelism were studied. The most relevant features were: 84.3% corresponded to cutaneous loxoscelism (CL) and 15.7% to viscerocutaneous loxoscelism (VCL); 73.6% occurred in hot season; in 86.6% of cases the accident happened in the house, particularly in bedrooms, while the people were sleeping or dressing. The spider was seen in 60.2% of cases and identified in the laboratory as L. laeta in 10.6% of all cases. The sites more frequently bitten were the limbs with 67.6%; a burning-stinging was the most frequent initial symptom. Pain, edema and livedoid plaque, which developed later into a necrotic eschar, were the predominant local manifestations. In VCL, hematuria and hemoglobinuria were constant, while jaundice, fever and sensorial involvement were present in most of the cases. CL patients were parenterally treated with antihistaminic drugs or corticoids, while VCL ones were treated with corticoids by injection. The condition of patients in the last follow up was: complete cure in 75.5%, cure with a scarfed sequela in 8.3%, death in 3.7% (all VCL) and abandonment in 12.5%. Additionally, a series of experimental studies, both in vivo and in vitro, has been performed in order to clarify basic aspects on L. laeta venom and the treatment of loxoscelism.

Congenital Chagas disease of second generation in Santiago, Chile. Report of two cases.

Congenital Chagas disease (CChD) has been reported in different countries, mostly in Latin America. In 1987 a fatal case of CChD of second generation (CChDSG) was published. Within a period of six months--1989-1990--two cases of CChDSG were diagnosed and studied in the city of Santiago. Two premature newborns, sons of two sisters, with moderate liver and spleen enlargement, were found to have positive serology for Chagas disease and xenodiagnoses. The mothers, urban residents all their lives, without antecedents of triatomine bugs contact or blood transfusions, showed positive serology and xenodiagnoses. Their mother (grandmother of the infants), lived 20 years in a Northern rural Chagas disease endemic locality, in a triatomine infested house. Afterwards, she moved to Santiago, where she married and has resided up to now. Serology and xenodiagnoses were also positive. All the Trypanosoma cruzi infected individuals were successfully treated with nifurtimox.

Seroepidemiology of human toxoplasmosis in Chile.

A series of already published and unpublished seroepidemiological surveys for toxoplasmosis, carried out in Chile in 1982-1994, is reviewed, expanded and analyzed. The surveys included 76,317 apparently healthy individuals of different ages (0.57% of the country's total population), from 309 urban and rural-periurban localities. Urban groups were integrated by blood donors, delivering mothers and middle grade schoolchildren, while rural-periurban individuals corresponded to unselected family groups. Blood samples were collected in filter paper. The presence of antibodies to Toxoplasma gondii was determined by the indirect hemagglutination test (IHAT), titers > or = 16 were considered positive. The test resulted positive in 28,124 (36.9%) of the surveyed people. Two hundred and six (0.3%) individuals presented IHAT titers > or = 1000, probably corresponding to acute or reactivated infections. A progressive increase of positive IHAT from northern to southern regions of the country was noted, phenomenon probably related to geographical conditions and to a higher production and consumption of different types of meat in the latter regions. It is postulated that ingestion of T gondii cysts by humans is epidemiologically as important as ingestion of oocysts. The result presented stress the epidemiological importance of toxoplasmosis in humans, and warn about eventual implications in immunocompromised patients and in transplacental transmission, organ transplants and transfusions.

[Cutaneous loxoscelism with edematous predominance]. / Loxoscelismo cutáneo de predominio edematoso.

Loxoscelism is the clinical condition produced by the venom of spiders belonging to the genus Loxosceles. Human cases of loxoscelism have been observed in diverse countries of different continents in temperate and tropical regions. In Chile loxoscelism is caused by Loxosceles laeta, spider with domestic habits. Loxoscelism can be observed into two well definited clinical variants: cutaneous loxoscelism (CL) and systemic or viscerocutaneous loxoscelism (VCL) which occur in around 83.3 and 16.7% cases respectively. Within the universe of CL patients a clinical modality in which necrotic lesion is not present or is insignificant, but presenting a remarkable edema, particularly when the bite is on the face, which has received the name of CL with an edematous predominance (CLEP). In this paper the individual description and the assambled analysis of 10 cases, four males and six females, age ranging from 6 to 68 years, of CLEP are presented. Nine cases occurred in warm periods spring through fall and one in winter. In six cases the accident causing spider was seen and two of these were identified as L. laeta adult females. In all cases the patients went or were transported to emergency medical services 4-24 h after the bite. The predominant initial symptom was a burning stinging sensation at the site of the bite, followed by intensive pain which expanded the neighbour areas concomitantly with the emerging and progressive edema. In four of the nine patients in who the bite was on the face, the edema involved all of it, closed both eyelids and expanded to the neck and upper part of the thorax. In three cases the enormous edema was the only significant clinical manifestation, whereas in the remaining seven conjunctly with the edema, a small violaceous plaque or a blister of serous content gave place to a little livedoid plaque (diameter 0.3-0.8 cm) which evolved to desquamation without leaving any scarring. The edema was characterized by its brilliant rose color, painful and hard which is not accompanied by regional adenopathy. Treatment of the 10 patients depended on the moment in they were seen by us. It consisted on parenteral administration, according to age and weight, of 5-10 mg of chloroprofenpyridamine maleate every 8 hours for be continued every 12-24 hours until the patient was discharged. Parenteral route was preferred in order that it was going to be adequately absorbed. With the beginning of the antihistaminic treatment a clear diminution of pain and edema was obtained, being possible its total disappearance within 4-10 days. CLEP occurs in about 4% of loxoscelism cases, has a benign prognosis and an early response to adequate medical treatment. Without discarding the sensibility factor of the affected individual, there exist the impression that the edema may abort the necrotic process when it dilutes the enzymatic process produced by L.laeta venom. In Chile, the differential diagnosis must be planted with the following clinical entities: bites of hematophagous insects on the face, bee stings, Chagas' disease with facial port of entry and angioneurotic edema.

[Human infection by Trypanosoma cruzi in Chile: epidemiology estimates and costs of care and treatment of the chagasic patient]. / Infección humana por Trypanosoma cruzi en Chile: algunas estimaciones epidemiológicas y de los costos de la atención y tratamiento del paciente chagásico.

According to the gathered information from the 1992 Chile census and an extensive epidemiological field study of Chagas' disease in rural-periurban sections of the seven most northern regions where this malady is endemic, the following epidemiological outline arises: Total population in the country 13,348,401. Population in endemic regions 8,824,205 (urban 8,050,700, rural 773,505). Number of infected 142,000 (16.7%). Total number of cardiopathies 26,554 (18.7%). In considering the regime of fees for health attentions of the National Health Funds--including hospitalization, laboratory tests and surgical interventions--in its minimal prices plus the value of medicaments, it is possible to produce some estimates on the cost of attention and treatment, in U.S. dollars, of the chagasic patient. Average annual cost of a patient with chronic chagasic cardiopathy U.S. $439.29 to U.S. $584.25 If these values are multiplied by 26,554 give rise to a figure ranging from U.S. $11,644,906 to U.S. $15,514,474.

[Special program on research and training in tropical diseases]. / Programa especial para investigación y adiestramiento en enfermedades tropicales (TDR).

A description of the six tropical diseases involved in this programme and the achievement of research goals are evaluated. The author points out the important accomplishment of these aims in the impact in the malaria and filiariasis control, in the elimination of leprosy and the future eradication of Chagas disease in the Americas. At the same time the relevance of the manpower training were emphasized in the strengthening on the research infrastructure of the member countries.

[Parasitology and entomology in the 29th century in Latin American narrative]. / La parasitología y la entomología en la narrativa latinoamericana del siglo XX.

In the present review of twelve pieces produced by distinguished 20th century Latin American writers--Jorge Luis Borges from Argentina, Jorge Amado and João Ubaldo Ribeiro from Brazil, José Donoso from Chile, Gabriel García Márquez from Colombia, Alejo Carpentier from Cuba, Miguel Angel Asturias from Guatemala, Octavio Paz from Mexico, Mario Vargas Llosa from Perú, Horacio Quiroga and Mario Benedetti from Uruguay and Arturo Uslar-Pietri from Venezuela--paragraphs or parts of paragraphs in which parasitological or entomological situations of the most varied hues are referred to or described, have been extracted in a selective form. Sometimes in these descriptions appear, local or regional expressions, without ignoring colorful folklore representations. For a easier interpretation these or part of these paragraph sentences have been arranged by thematic similarities. In a varied and kaleidoscopic vision, it will be possible to find protozoiasis (malaria, Chagas disease, leishmaniasis, amebiasis), helminthiases (ascariasis, hydatidosis, trichinosis, schistosomiasis, cysticercosis, onchocerciasis), parasitoses produced by arthropods (pediculosis, scabies, tungiasis, myiasis), passing progressively to hemaphagous arthropods (mosquitoes, gnats, horse flies, bedbugs, ticks), venomous arthropods (Latrodectus spiders, scorpions, wasps, bees), mechanical vectors (flies and cockroaches), culminating with a conjunction of bucolic arthropods (butterflies, crickets, grasshoppers cicadas, ants, centipedes, beetles, glow worms, dragonflies).

[Eyelids infestation by Phthirus pubis in a boy]. / Infestación de los párpados de un niño por Phthirus pubis.

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 eggs 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.

[Diagnosis in 1348 patients which consulted for a probable spider bite or insect sting]. / Diagnósticos hechos a 1384 pacientes que consultaron por probable mordedura de arañas o picaduras de insectos.

Accumulate experience, from 1955 to 1995, in an outpatient university parasitology clinic in Santiago, with 1,384 patients referred from diverse public and private medical institutions because of a probable spider bite or insect stings, is presented. It is noteworthy that only 618 (44.7%) of consultations corresponded to clinical conditions originated by arthropods, whereas from the remaining 766, 612 (44.2%) were due to a bacterial, viral or parasitic etiology and 154 (11.1%) were caused by physical or chemical agents. Frequency of diagnosis was: loxoscelism 16.6%, spider bites (excluded Loxosceles laeta) 1.3%, scorpion sting 0.9%, tick stings 2.2%, insect bites 23.7%, impetigo 6.6%, folliculitis 11.3%, boil 22.7%, erysipelas 0.1%, pustula maligna 0.3%, herpes simplex 2.5, palpebral herpes zoster 0.3%, acute Chagas' disease 0.4%, angioneurotic edema 0.1%, ecchymosis 3.0, contact dermitis 7.8% and chemical dermitis 0.2%. These frequencies do not indicate the real occurrence of the diagnosed nosologies, but what happened in a specialized outpatient clinic dealing cheaply with parasitic diseases and arthropod envenomations. Description of relevant clinical features and epidemiological considerations of pathology observed, conjointly with differential diagnosis are presented.