Treatment of Trypanosoma cruzi-infected children with nifurtimox: a 3 year follow-up by PCR.

Patients suffering from Chagas' disease, as determined by positive serological results, were tested for further evidence of Trypanosoma cruzi infection by xenodiagnosis and PCR. The patients included 67 children aged from 0 to 10 years and 75 adults. All children were positive by PCR on their pre-therapy sample, while only 69% of the seropositive adults and none of the 78 seronegative control adults were PCR positive. Xenodiagnosis was positive in 79% of the children, but only in 21% of the adults. A group of 66 children was treated with nifurtimox, and followed up every 3 months during the first year and every 6 months during the second and third year post-therapy, by PCR, xenodiagnosis and serology. We concluded that PCR was the most effective test to monitor children for 3 years post-chemotherapy, when all the cases converted from positive to negative. Conventional serology, however, remained positive after that period in most cases. In contrast, conversion to negative xenodiagnosis occurred very early after treatment.

[Imported myiasis: 7 cases of cutaneous parasitism caused by Dermatobia hominis flie larvas]. / Miasis importada: siete casos de parasitación cutánea por larvas de la mosca Dermatobia hominis.

Myiasis is the parasitism of organs and tissues of warm-blooded vertebrates by flies larvae. D hominis is a flie geographically restricted to tropical America from Mexico to northern Argentina. The adult flie, which is not hematophagous, needs to put its eggs on the abdominal surface of hematophagous arthropods which serve as carriers of future larvae which are deposited on the skin of the hosts (mammals, birds and accidentally men) when biting. Seven patients (two females) aged 7 to 35 years old, of different nationalities, recalled receiving mosquito bites, after staying in tropical American areas in the previous forty days. They presented furuncle-like lesions in exposed surfaces of the body. These lesions, 2-3 cm long, pruritic and mildly tender, broke and released a serous or serohematic fluid. Through the resulting opening, it was possible to partially observe the larva. Larvae were extracted by manual pressure (4) or surgical incision (3) and identified as D hominis larvae. Diagnosis of dermatobiasis, an imported myiasis, must be based on the characteristics of lesions and the previous residence in endemic areas of America.

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.

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.

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.

[Comparative study of sensitivity and mortality of Triatoma infestan nymphs III and IV used in the xenodiagnosis of chronic chagasic patients]. / Estudio comparativo de la sensibilidad y mortalidad de las ninfas III y IV de Triatoma infestans usadas en el xenodiagnóstico de pacientes chagásicos crónicos.

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 a satisfactory yield. With the aim of an eventual improving of the yield 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.

[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.

[Comparison of Trypanosoma cruzi infection in less than 10 years old children from the V Región, Chile, 1982-1995]. / Comparación de la infección por Trypanosoma cruzi en niños menores de 10 años de la V región, Chile. 1982-1995.

Evaluation of desinsectation programs carried out in the two Health Services from the V Region, was undertaken by comparing serologic prevalences of T. cruzi infection 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 from 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 cases were detected in the last five years it is possible to assume that vector transmission 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.

[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).

[Environmental contamination with Toxocara sp. eggs in public squares and parks from Santiago, Chile, 1999]. / Contaminación ambiental por huevos de Toxocara sp. en algunas plazas y parques públicos de Santiago de Chile, 1999.

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 microscopically 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.

[Epidemiological status of Chagas disease in the endemic area from Region II of Antofagasta]. / Situación epidemiológica de la enfermedad de Chagas en el área endémica de la II Región de Antofagasta, Chile.

During 1997 a seroepidemiological study on Chagas' disease was carried out in 18 localities of three provinces (Tocopilla, El Loa and Antofagasta) of Region II (20 degrees 56'-26 degrees South Lat.; 70 degrees 38'-67 degrees West Long.), in order to assess the impact of the control program against Triatoma infestans launched in 1988, based on insecticide spraying of dwellings. By means of ELISA and an indirect hemagglutination test for Chagas' disease blood samples from 1,034 children under 10 years of age were examined, arising a 0.5% (3 cases) positivity. Test resulted positive in 2 (0.9%) children from the locality of San Pedro de Atacama and 1 (0.4%) from Calama city, all in the age group 6-10 year-old. However, none of their dwellings were found infested with T. infestants. These results indicate that the control program has a good possibility to prevent new human infections. It is advisable to continue the seroepidemiological and entomological vigilance and remark the necessity of increasing the effort in the study of transmission through other routes, to adopt or reinforce the pertinent preventive measures.

[Longitudinal study, by xenodiagnosis, of parasitemia in patients with chronic Trypanosoma cruzi infection]. / Estudio longitudinal, mediante el xenodiagnóstico, de la parasitemia en pacientes con infección por Trypanosoma cruzi crónica.

A 2-5 years follow-up of parasitemia, by the use of xenodiagnosis (XD) was carried out in nine patients with chronic T. cruzi infection who proceeded from chagasic endemic areas of Chile. The patients (mean age 55 years) were hospitalized in the chronic section of a psychiatry institution sited in a permanent triatomines free urban area. Clinical examination, X-rays images (cardiovascular, esophagus and colon) and electrocardiogram resulted normal in all the patients. Basic study unit of parasitemia was a XD box which contained 7 nymphs III of Triatoma infestans which was used in a serial XD consisting in the simultaneous application of a pair of boxes a day during three consecutive days, making a total of six boxes (42 nymphs). The minimal time of duration of infection (M.D.I.) for each patient was estimated that this was adquired close to hospitalization. The M.D.I. varied between 6 and 45 years. The global positivity of XD boxes ranged between 6.3 and 84.7%, being in three patients lower than 12% and in six patients higher than 52%. In considering the yield of XD it is important to stress that during all the study of the nine patients with chronic chagasic infection 1282 XD boxes were applied resulting positive 582 (45.4%). At the end of the follow-up all patients received specific treatment for chagasic infection with nifurtimox at the daily dose of 10 mg/kg of body weight during 60 days. According to the result, two main conclusions arise: 1.--Serial XD has a high efficiency for detecting, evaluate and evolve parasitemia in patients with chronic chagasic infection. 2.--Parasitemia may present low, medium or high levels in different individuals and has a variable and fluctuating character.

[Human hydatidosis in Chile. Seroprevalence and estimate of the number of infected people]. / Hidatidosis humana en Chile. Seroprevalencia y estimación del número de personas infectadas.

Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising) and austral (sheep raising). Population (June 1999) 15,017,760 (14.6% rural). Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human hydatidosis in Chile, a series of serosurveys was carried out in 1988-1997 throughout the total country. By using the indirect hemagglutination reaction and ELISA for hydatidosis (tests with good sensibility and specificity) 60,790 unselected apparently healthy persons: 41,399 from urban areas (16,428 blood donors, 13,894 delivering mothers and 11,077 middle grade schoolchildren) and 19,361 from rural areas--from randomly selected family groupings--were studied. A total individuals 82 (136/100,000) resulted positive: 36 (87/100,000) urban and 46 (241/100,000) rural, being the prevalence higher in rural areas, particularly in the southern austral zone (mean 1068/100,00). These figures agree with those observed in clinical epidemiological studies. In conformity with the present results, in the whole country 17,002 individuals should have hydatidosis: 10,318 urban and 6,784 rural. All these possible infected people, not necessarily should present pathology in the future, as it has been observed in autopsies from unselected individuals, performed at the Medico-Legal Service in Santiago, in whom 71.3% of diagnosed hydatosis with hydatid cysts in many different locations, was an autopsy finding.

[Epizootic outbreaks of trichinosis in 2 pig farms from the Metropolitan Region of Chile]. / Brotes epizoóticos de triquinosis en dos criaderos de cerdos de la Región Metropolitana, Chile.

In Chile swine trichinosis has presented a progressive decreasing in the last two decades of XX century. T. spiralis pig infection descended from an average of 0.683 per 1000 in 1980-1984 to 0.315 in 1985-1989 and to 0.115 in 1990-1996. In the particular case of Metropolitan Region this decreasing has been more marked: from an average of 0.058 per 1000 in 1990-1994 to 0.003 in 1995-1999. Between the end of June 1999 and middle January 2000 in Metropolitan Region abattoirs T. spiralis was detected in 15 (4.9%) out of 306 swine from two pigsties located in El Monte (E.M.) and Padre Hurtado (P.H.) 45 and 30 km south-west from Santiago. In the same period another four pigs from the same premises were found infected in abattoirs of other regions. During inspection visits it was stated that both pig farms had deficient sanitary conditions. Phototrichinoscopy was positive in three out of five Rattus norvegicus collected in E.M. In pigsty PH the examination of diaphragm samples of 25 dogs and 17 cats resulted negative. In the premises originating T. spirali infected swine the Metropolitan Environmental Health Service Abattoirs Program carries out an epidemiological vigilance consisting in the follow-up of animals destined for slaughtering in order to initiate prophylactic actions oriented to eliminate eventual sources of trichinosis infection for human and rearing pigs.

[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.

[Yield of xenodiagnosis and PCR in the evaluation of specific chemotherapy of Chagas' disease in children]. / Rendimiento del xenodiagnóstico y el PCR para evaluar el tratamiento quimioterápico específico de la enfermedad de Chagas en niños.

Amplification by the polymerase chain reaction (PCR) of Trypanosoma cruzi kinetoplastic DNA was used to enhance sensitivity in the detection of the parasite in blood, with the ultimate goal of improving the parasitological diagnosis of Chagas' disease in 0-10 year-old infected children. Twenty eight children were evaluated by using xenodiagnosis (XD) and PCR. Whereas XD detected 75.0% of the cases PCR was positive in 96.8%. The usefulness of the PCR was further investigated in the 28 children who have received specific treatment with nifurtimox. Negativation of XD after three and six months post treatment was observed in all the cases, but only 21.4% and 35.8% negativation of the PCR after three and six months post treatment respectively. These observations suggest that PCR is the most sensitive and quick technique available for direct detection of T. cruzi in chagasic children and that it can be a very useful tool for the follow-up of infected subjects after specific chemotherapeutical treatment.

[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.

[Scorpion stings outbreaks in recently constructed urban dwellings inhabitants]. / Brotes epidémicos de picaduras de escorpión en habitantes de viviendas urbanas de construcción reciente.

Scorpion stings are unfrequent in Chile. Most of cases occur in rural areas during the warm season. Clinical manifestations have a low to moderate intensity and consist in local pain and inflammation, sometimes associated with headache and hyperthermia. Two autbreaks of scorpion stings--affecting six and five adult residents (18-42 years old) of recently built urban dwelling complexes--have been recorded in Chile in summertime of 1957 and 1998. The first took place in the town of Maipú and the second in Villa Alborada sites respectively 10 and 150 km South of the city of Santiago. The Maipú dwelling complex was constituted by 112 one story houses in which lived 504 people. In Villa Alborada live 1,050 persons distributed in 158 apartments, 86 of which are in the main floor and in 26 of these last the occupants have observed scorpions inside. All the 11 cases occurred into the dwelling: four when sleeping at night, three performing different activities (trying to find a tool, searching a kee, housekeeping), two when putting their shoes, and two walking with bare feet in dormitory. In all the cases the causative scorpion was observed, captured or destroyed. Identification of six specimens from Maipú corresponded to Brachistoternus ehrenbergi and of two from Villa Alborada to Bothriurus borrelianus. All the patients presented mild to moderate symptomatology. Treatment consisted basically in oral antihistamanic and/or antinflammatory tablets. Recovery was observed within one to seven days with a mean of three days. Prophylactic measures consisted in health education and physical destruction of scorpions in Maipú and insecticide spraying on floors of basement apartments and surrounding areas in Villa Alborada. Though the majority of accidents by scorpion stings happens in rural areas, also may occur in urban areas--rural in the near past--where dwellings have been constructed in fields which in not to much preterit times constituted the habitat of the referred arthropod, phenomenom that have occurred in summertime in the two dwelling complexes described in the present communication.

[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.