Boletin chileno de parasitologia最新文献

The evolution of the specific treatment of Chagas' disease, including the numerous drugs tested, is briefly summarized. Since 1969 laboratory and clinical studies have persistently demonstrated that nifurtimox (NFX) and benznidazole (BNL) are the best agents for treating Trypanosoma cruzi human infection, even though they cannot be considered ideal drugs. The main indications for NFX and BNL are: acute phase of the infection, congenital form, reactivation associated with immunosuppression, recently acquired infection, mostly in children and young adults, and in transfusions and organ transplant situations. Both drugs may also be indicated for the treatment of some patients in the undetermined asymptomatic form of the chronic infection with mild heart involvement, or in clinical megaesophagus patients who previously need symptomatic treatment to ensure the appropriate absorption of the medication. The most used dosage schedules are: NFX for 60-90 days, 8-10 mg/kg/day in adults and < 15 mg/kg/day in children. BNL, for 60 days, 5 mg/kg/day in adults and < 10 mg/kg/day in children. Both drugs are taken orally and must be given divided into 2-3 fractions after meals. Both drugs are well tolerated by children, and particularly in the acute phase of the disease. Adverse reactions may be observed, i.e. disturbances associated to the digestive tract such as hyporexia, nausea, vomiting and loss of weight with NFX, and dermopathy and polyneuropathy, with BNL. The main limitations of both drugs are in the long course of administration and the occurrence of adverse side effects. A series of promising new drugs for the treatment of human Chagas' disease is being tested. Because the relative lack of interest of the pharmaceutical industry in the research for new drugs for the treatment of the parasitosis--which affects 16-18 million people in Latin America--Universities and Research Governmental Institution should stimulate the investigation for the development of new drugs and the clinical evaluation of drugs experimentally known and not yet tested.

During 1995, we examined 2,666 Graham's tests (five perianal swabs with adhesive cellulose tape) prescribed to ambulatory patients attended in 14 public outpatient clinics and four hospitals from the north section of Santiago. The infection rates found by age groups were the following: 6.1% in infants (< 2 years old), 20.9% in pre-schoolchildren (2 < 6 years old), 35.2% in elementary schoolchildren (6 < 15 years old) and 15.2% in adults (> 15 years old). Similar percentages of E. vermicularis infections were observed in females and males patients. Frequency of infection in each month of the year varied between 17.4 and 26.8%, with no seasonal variation. This study and previous surveys are stressing that E. vermicularis is the most frequent helminthic agent found in Chile, specially in elementary school children.

We report 29 new localities with Triatominae in the Republic of México; these Triatominae belong to 8 different species. Infection by Trypanosoma cruzi in the majority of these localities with high rates of positivity was found. Biological observations concerning the collected Triatominae are given. The necessity of continued work in relation to geographical distribution, ecology, frequency of infection by T. cruzy, and the role played by Triatominae of the Republic of México in the transmission of the infection to the man is stressed.

Chagas' disease is a parasitic zoonosis with high prevalence in Chile. It is distributed in rural and periurban section in the northern most seven out of thirteen regions in which the country is divided, and affects about 142,000 individuals dispersed in most of the 165 counties sited in the chagasic zone. Triatoma infestans--intradomiciliary species--is the main and practically exclusive vector of Trypanosoma cruzi. Diverse tools may be utilized in order to interrupt the domestic cycle of transmission of T. cruzi: health education, housing improvement and elimination of vectors by dwelling insecticide sprayings. This last resource has received priority in Chile in the last 12 years. To evaluate the effectivity of the programs for eliminating T. infestans a serological study for Chagas' disease--comprising 8,767 children less than 10 years old from 27 rural counties insecticide sprayed in the last 12 years--was carried out. A global total of 125 (1.4%) children resulted positive, figure significantly lower than 5.4% found in 1982-1990 in the same age group. Distribution by regions of positive individuals showed a decrease of prevalence in each of them: III Region, from 9.8 to 1.0%, IV Region, 7.2 to 2.0%, V Region, 5.2 to 1.9%, and Metropolitan Region, 1.4% to 0.6. Even though positive children have still been found in 46.7% of localities of the studied counties, it is possible to affirm that the vector control programs have been effective and must be maintained, and increased in those localities with T. cruzi infection in children under 10 years of age, with the general aim of eradicate Chagas' disease transmission in Chile before 2000.

Adult specimens of Camallanus genus (Nematoda, Camallanidae), parasitizing a Hydrodynastes gigas (Serpentes, Colubridae) from Chaco in the North East of Argentina, are described for the first time. The morphologic and morphometric parasitological studies were carried out using diaphanization by lactophenol technique. The specimens described were drawn and photographed. With this investigation the analysis of the reptilian pathologies, the knowledge of which is necessary to make projects, to manage and control the biomedic aspects in breeders, zoos and/or reserves has started. Thus, it enables us to know associated nematofauna providing facts about the biodiversity of nematode parasites of reptiles.

Hydatidosis situation in the General Acha area (La Pampa Province) is described herein. The work comprises a retrospective compilacion of new hydatidosis human cases, the findings in seroepidemiological surveys with enzyme immuno assay (EIA) for hydatidosis in human population, and investigation on dog Echinococcus granulosus infection prevalence carried out on the basis of arecoline bromhydrate application. Sixteen human cases were detected during 1994 (incidence rate: 26.7/100,000), founding a serological prevalence of 1.3%. Studies on dog echinococosis have shown a prevalence rate of 2.3%. The epidemiological situation of hydatidosis is analyzed by comparison with values from other endemic areas. These results suggest the necessity of completing surveys in the whole provincial territory, and the implementation of educational and sanitary measures aimed to controlling this zoonosis.

In order to assess the impact of a control program against Triatoma infestans launched in 1988, based on insecticide spraying of dwellings, a serological survey for chagasic infection was carried out during 1995 in three localities from San Pedro de Atacama County (22 degrees 55' South lat., 68 degrees 12' West long.), II Region of Antofagasta in northern Chile. Blood samples from 531 children and adolescents and 65 dogs were subjected to ELISA test and indirect immunofluorescent test for Chagas' disease respectively. Tests resulted positive in 12 (2.3%) persons, all above 5 years old, in contrast with the 16.8% serological positivity observed in 1985. Three (4.6%) dogs (two 0-12 months old) resulted positive. These results indicate that dwelling sprayings with long-term activity insecticides against T. infestans is a good tool to prevent new human infections with T. cruzi. However, active vector transmission among domestic animals (canines) could be recently acquired.

Control of quality of coproparasitological diagnosis was carried out in the Province "Las Tunas", between January and March 1993, It was found that 72% of coproparasitological microscopists had deficiencies related to the diagnosis, due to several causes: The microscopists did not receive any periodical training, as they did not participate at the parasitological section; the microscopists had no manual of reference; they had less than ten years of experience; they did not know the concentration technics that were established in the country. Between July 1993 and January 1994 two Medical Parasitology Courses were imparted. In July 1994 another quality control was performed. 80% of evaluated microscopists obtained good results. Through this study was established the National Parasitology Quality System Control that supports the National Intestinal Parasites Control Program.