Caracteristicas clinica y epidemiológica de la Leishmaniasis Visceral canina en Paraguay / Annual reports 1998 / Clinil and epidemiological characteristics of canine Visceral Leishmaniasis in Paraguay

La leishmaniasis visceral es una enfermedad sistémica causada por ls diseminación de parásitos del complejo donovani a través del sistema retículoendotelial. Aparece en las grandes urbes al darse una adecuada combinación de factores, como la adaptación del vector a un nuevo medio ambiente y la presencia del principal reservorio de la enfermedad en las ciudades, el perro doméstico. A raíz del diagnóstico parasitológico que se realizó en una biopsia nasal de un perro de raza en el Instituto de Investigaciones en Ciencias de la Salud en 1994, se inició una intensiva investigación con veterinarios de Hospital de la Facultad de Ciencias Veterinarias y clínicas veterinarias. Desde enero de 1997 hasta agosto de 1998 fueron examinados serológicamente 580 perros con síntomas compatibles con la enfermedad, resultando positivos 198 (34,14 por ciento). Las razas más afectads en orden decreciente fueron la mestiza, ovejero alemán, Dobermann, Boxer y Rottweiler. Los municipios con mayor número de casos fueron Asunción, Lambaré, San Lorenzo, Villa Elisa, Fernando de la Mora, Areguá, confirmándose casos clínicos en 28 barrios de Asunción. El mayor número de casos se encontró en animales de 2 y 3 años, y los síntomas más frecuentes fueron lesiones en las orejas, hocico, ojos, piel, patas, mucosa y cara. También fueron observados pérdida de peso, hipertrofia ganglionar, fiebre y crecimiento de uñas. Este trabajo enfocó animales con síntomas compatibles de infección con L. cvhagasi, por lo tanto no refleja la prevalencia real de la enfermedad. De manera a determinar la dinámica de la infección en Paraguay son necesarios estudios epidemiológicos en nuestras representativas

Caracterización de cepas Paraguayas de Trypanosoma Cruzi aislada de pacientes agudos de la enfermedad de Chagas / Characterization of paraguayan Trypanosoma Cruzi strains isolated from acute patients of Chagas disease / Annual Reports 1992

Six Trypanosoma Cruzi Paraguayan strains, isolated from accute chagasic patients, were studied by their behaviour in Bald/C mice, metacylogenesis, biometry of metaciclic froms and lectin agglutination. Early, intermediate and late parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50 percent in all cases, and there were no big differences inthe biometry and lectin agglutination assays. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological feautures were quite heterogeneous

Especies de moscas flebótomas en Paraguay y su infeción con Leishmania / Annual Reports 1992 / Phlebotomine sandfly species in Paraguay and their infection with Leishamnia

Nine species of sandflies, Lutzomyia. All the species collected were found to be anthropophilic. Hindgut infections with leishmanial promastigotes were observed in only one (0-38 por ciento) of the 266 L. whitmani dissected. No L. intermedia were found infected, giving an overall infection rate of one (0-16 por ciento) of 615 flies dissected. The results indicate a very low rate of natural infection in endemic areas of Paraguay

Reservorios animales de la nfección con Trypanosoma Cruzi aisladas de pacientes agudos de la enfermedad de Chagas / Annual Reports 1992 / Animal reservoirs for Trypanosoma Cruzi infection in an endemic area in Paraguay

Animal reservoirs for Trypanosoma Cruzi infection were investigated in 5 communities in the Departament of San Pedro, currently one of Paraguayïs most hihly endemic areas. A total of 112 domestic animals(37 cattle, 2 horses, 1 ass, 20 pigs, 44 dogs and 8 cats) and 4 wild animals (1 white-eared opossum, 2 yellows armadillos and 1 common long nosed armadillo) were examined. Although trypomastigotes were not found by 2 direct observations, the microhaematocrit method or on giemsa stained thick and thin smears, flegellate parasite morphologically identical to T. Cruzi were detected in the liver infusion tryptose (LIT) medium from a single sample taken from a yellow armadillo

Metaciclogénesis de Trypanosoma cruzi / Metacyclogenesis of Trypanosoma cruzi / Annual Reports 1991

Spontaneous metacyclogenesis in culture of two Paraguayan T. cruzi strains has been studied. T. cruzi JAG and RF, two stains isolated from patients at IICS, maintained through successive cultured in LIT medium and the reference strain, y, were cultured in modified Grace medium (isola et. al. 1986), for the purpose of evaluating their ability to develop into the metacyclic trypomastigote from in vitro. T. cruzi y showed a cosiderable higher yield of metacyclic froms (55 percent), as compared with the JAG and the RF strains did not show a significant difference in terms of their metacyclogenic power. These results will be useful in the characterization of T. cruzi strains isolated in Paraguay

Actividad tripanocida de productos naturales contra formas sanguineas tripomasrigotes de Trypanosoma Cruzi / Trypanocidal activity of natural products against blood Trypomastigote forms of Trypanosoma cruzi / Annual Reports 1991

Blood trnasfusion is the second most importnatmechanism of transmission of Chagas'disease in both endemic and non-endemic areas. In Latin America, more than 20,000 cases of transmission of the disease, trough blood transfusion, may be occurring. Gentian Violet is currently the only available trypanicidal agent used for treating blood before transfusion. The main disadvantages of this treatment are the time required to allow drug action before transfusion and the coloring of the blood. In vitro trypanocidal effect of plant extracts and that of pure compounds are assessed against trypomastigote blood forms of T. cruzi. The induction of sister chromatid exchange (SCE) in human lypocytes was performed to evaluate mutagenic effects of these compounds. Eight compounds had a high activity against blood forms of T. cruzi at a concentration of 250 mg/ml; namely, daphnandrine, limacine, pheantine, daphnoline and cocsuline. Plumbagin (a naphthoquinone) also showed high trypanicidal activity and has previously been recognized as a leismaniacidal, bactericidal and fungicidal, compound. Daphnoline showed low values for both LC50 (8mg/ml) and LC90 (50mg/ml) and was the only tested compound which did not induce sister chromatid exchange below 10 mg/ml. Therefore, deeper evaluations of these compounds should be considered

Infección experimental de monos Cebus apella con Trypanosoma cruzi: Datos preliminares de parasitemia / Annual Reports 1991 / Experimental infection of Cebus apella monkeys with Trypanosoma cruzi. Preliminary data on parasitemia

Three Cabus apella monkeys were infected with 3.5 x 10 sobre 5 cells of Trypanosoma cruzi Y strian in order to evaluate the parasitemia and to study the behavior of the parasites in the mammalian host for a one-year period. The parasitemia was determined by hemoconcentraction. In the there monkeys, circulating parasites were detected in blood one week after infection. Parasitemia persisted in two monkeys one year after infection, but not continuously. Cyclic peaks of parasitemia were not detected

Tratamiento con ivermectina de Cebus apella con Dipetalonema gracile / Annual Reports 1991 / Treatment of dipetalonema gracile in Cebus apella by invermectin

The microfilaricidal effect if invermectin was studied on Cebus apella infected with dipetalonema gracile in Paraguay. Nine monkeys were treated with ivermectin at the dosage of 200 ug/kg boby wieght by single subcutaneous injection. The significant reduction in microfilarial count after treatament with ivermectin was recognized (p<0.01). The change of blood picture of 9 monkeys infected with Dipetalonema gracile following treatment of ivermectin was also studied. The total WBC count was found to be significantly increased at 1 day after treatment. Differential count study showed that neutrphlilis increased in most menkeys. On the other hand, the significant change in eosinophil and lynphocite count was not observed

Clave gráfica para indentificación de flebótomos paraguayos / Graphic key for the identification of paraguayan phebotomines / Annual Reports 1991

A graphic key for the identification of male and female phlebotomines caught in Paraguay was prepared. The objective of this work is to facillitate the identification of these insects by health workers interested in leihmaniasis control

Phlebotomes of Paraguay species identification in 3 endemic areas: diptera, psychodydae, and phlebotominae

In an attemp to contribute to a better knowledge of the leishmania-transmitting insect species in endemic areas of Paraguay, phlebotomes were collected by night catch. In this way, species of insects could be identified and natural infections could also be discovered. Six-hundred and six females bugs were examined, from among which the following species were identified: Lutsomia migonei (11%), L. shannoni (13.6%, L. intermedia (20.3%), L. wakeri (0.2%), L. whitmani (60.4), L. fisheri (2.6%), L. longispinosa (0.7%), and L. cortelezzi (0.2%). The last three species were first described in Paraguay. L. whitmani was the most frequently found species. Insect catch was performed in four Paraguayan localities in three endemic areas, using Shannon light traps and human bait, Leishmania promastigotes were found in the Malpighi tubes of a specimen of L. whitmani. All the other species mentioned above are also considered as vectors for Leishmania. Very little study has been performed on Phlebotomines in Paraguay. In 1955, González y Arce Queirolo collected 5401 specimens in endemic areas, Nad identified the following species: Ph. whitmani, Ph. migonei, Ph. intermedius, Ph. monticulosus, dnd Ph. pessoai (3). These species were cited by Barreto (1950) in his report on the distribution of phlebotomines in America (1). Between 1984 and 1985, A. de Arias performed an epidemiological survey in Tavapy (Alto Paraná), collecting the following species: L. intermedie, L. migonei and L. whitmani (6). Although all the species quoted by the different authors are considered vectors for Leishmania, they failed to find specimens infected with the parasite. In the present work we report some data on the species found in three endemic zones as well as the method of catch employed, and finally we mention some aspects of the natural infection