Intradomiciliary and peridomiciliary captures of sand flies (Diptera: Psychodidae) in the leishmaniasis endemic area of Chapare province, tropic of Cochabamba, Bolivia.

In South America, cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis. Bolivia is one of the countries with higher incidence, with 33 cases per 100,000 individuals, and the disease is endemic in 70% of the territory. In the last decade, the number of cases has increased, the age range has expanded, affecting children under 5 years old, and a similar frequency between men and women is found. An entomological study with CDC light traps was conducted in three localities (Chipiriri, Santa Elena and Pedro Domingo Murillo) of the municipality of Villa Tunari, one of the main towns in the Chapare province (Department of Cochabamba, Bolivia). A total of 16 specimens belonging to 6 species of the genus Lutzomyia were captured: Lu. aragaoi, Lu. andersoni, Lu. antunesi, Lu. shawi, Lu. yuilli yuilli and Lu. auraensis. Our results showed the presence of two incriminated vectors of leishmaniasis in an urbanized area and in the intradomicile. More entomological studies are required in the Chapare province to confirm the role of vector sand flies, the intradomiciliary transmission of the disease and the presence of autochthonous cases of cutaneous leishmaniasis.

Tripanosomátidos aislados de mamíferos silvestres en tres departamentos de Bolivia (Cochabamba, Potosí y Santa Cruz de la Sierra) / Trypanosomatidae isolated from wild mammals in three departments of Bolivia (Cochabamba, Potosi and Santa Cruz de la Sierra)

Objetivos: el objetivo de la investigación fue aislar protozoarios kinetoplástidos a partir de mamíferos silvestres en tres departamentos de Bolivia, con la finalidad de identificar reservorios de tripanosomátidos que podrían causar infección en diferentes reservorios y enfermedades en el humano. Métodos: Los mamíferos silvestres fueron capturados en el Chaco, valles interandinos y la zona tropical de Bolivia, utilizando trampas Sherman, Havahard y Tomahawk. Los animales capturados fueron anestesiados para realizar el xenodiagnóstico y la extracción de sangre por punción cardiaca; el aislamiento de tripanosomátidos se realizó por hemocultivo utilizando medios de cultivo NNN y su respectiva identificación por las técnicas de PCR-RFLP en el laboratorio de Biología molecular IIBISMED. Resultados: fueron capturados 236 mamíferos silvestres pertenecientes a 30 especies, de las cuales 7 especies presentaron infección por hemoflagelados. Trypanosoma cruzi fue aislado de Didelphis marsupialis, D. albiventris, Galea musteloides, Graomys domorum y Andalgalomis pearsoni; T.c marinkellei y T. dionisii fueron aislados de Carolia perspicillata (murciélagos) y otros kinetoplástidos no identificados por herramientas moleculares disponibles fueron aislados de mamíferos del género Graomys y Andalgalomys, capturados en las provincias Campero de Cochabamba y Cordillera del departamento de Santa Cruz. Conclusiones: El T. cruzi, T.c. marinkellei, T. dionisii y otros tripanosomátidos se encuentran infectando a marsupiales (Didelphis), roedores (Graomys y Andalgalomys) y cobayos silvestres (Galea) los cuales se encuentran en su ciclo silvestre en las zonas estudiadas.

Objectives: The aim of this research was isolate kinetoplastid protozoan from wild mammals in three departments of Bolivia, to identify Trypanosomatids reservoirs that could cause infection in different reservoirs and disease in humans. Methods: The wild mammals were caught in the Chaco, valleys and the tropical zone of Bolivia, using Sherman, Havahard and Tomahawk traps. Captured animals were anesthetized and xenodiagnosis and blood cardiac puncture was performed; trypanosomatides isolation using blood culture was done in NNN culture media and the respective identification was performed by PCR-RFLP techniques in the molecular biology laboratory of IIBISMED. Results: 236 wild mammals belonging to 30 species were captured, of which 7 species showed infection by hemoflagellates. Trypanosoma cruzi was isolated from Didelphis marsupialis, D. albiventris, Galea musteloides, Graomys domorum and Andalgalomis pearsoni; T.c. marinkellei and T. dionisii were isolated from Carolia perspicillata (bats) and other kinetoplastid not identified by available molecular tools were also isolated from Andalgalomys and Graomys mammals genus, from Campero and Cordillera provinces of Cochabamba and Santa Cruz. Conclusions: The T. cruzi, T.c. marinkellei, T. dionisii and other trypanosomatids are infecting marsupials (Didelphis), rodents (Graomys and Andalgalomys) and wild guinea pigs (Galea) which are found in a sylvatic cycle in the studied areas.

Efectos de la infección materna por Trypanosoma cruzi en el desarrollo del embarazo y del recien nacido / Effects of maternal infection with Trypanosoma cruzi in pregnancy development and in the newborn infant

In the endemic regions of Bolivia the infection of the feminine population in fertile age by T. cruzi is frequent (20 to 50 % of the women in fertile age) and the rate of fetal maternal transmission is of approximately 5%. A great percentage of infected women do not transmit the infection to the fetus. The intention of the present study carried out at the Maternal-Infantile Hospital Germán Urquidi of Cochabamba (Bolivia) is to contribute to the knowledge regarding the pregnancy and birth of a newborn of Chagas infected women who do not transmit the infection to the fetus. 2124 mothers and 2,155 newborns were studied. The prevalence of infection by T. cruzi among these pregnant women is of 26,3%. Two groups of mothers were studied: 554 that presented infection by T. cruzi (group M+B-) and 1520 not infected (group control M-B-). Both groups of mothers are comparable in their anthropometric and obstetrical antecedents. The mothers (M+B+) are in average older than those not infected (p<0.05), which will probably have an influence on the number of gestations and abortion antecedents, which were of p<0.05 and p=0.01 respectively. Among the different anthropometric and biological parameters studied in newborns of groups M+B- and M-B -, no statistically significant differences between both groups were found. It can be inferred that the chronic maternal infection by T. cruzi seems to have no clinical influence, neither on the course of the pregnancy nor during birth, if a group of T. cruzi infected mothers is compared to a non infected group.

Estimación de la parasitemia en la infección humana por Trypanosoma cruzi: las altas parasitemias están asociadas con la severa y fatal enfermedad de Chagas congenita / Estimation of the parasitemia in Trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital Chagas disease

The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.

Nivel de endemia de la infección por Trypanosoma cruzi en el lugar de residencia de la madre y desarrollo de la enfermedad de Chagas congénita en Bolivia / Endemic level of congenital Trypanosoma cruzi infection in the areas of maternal residence and the development of congenital Chagas disease in Bolivia

In Bolivia, the prevalence of infection by T. cruzi in women in fertile age can vary between 20 and 60%. The present study made in the Maternity Germin Urquidi of Cochabamba - Bolivia, it has demonstrated, that 19.9% of the mothers who go to this hospitable center to be taken care of in the childbirth, they are carrying of the infection and that 4,6% of them, they are going to transmit, by transplacentaria route, the infection to its babies. Of the 71 children born with congenital Chagas, only 47,8 % present/display some type of alteration or of development(Apgar to 1 minute low, BPN, prematuridad, pathological dismadurez) or signs (SDR, hepatomegalia, esplenomegalia, neurological signs, cardiomegalia, anasarca, petequias). When investigating the effect of the differences in the vectorial density (low, medium and high) of the zone of maternal residence, on the transmission of the infection of the mother infected to the fetus, we concluded that the rate of transmission of the congenital infection of T. cruzi is not modified by the level of endemicidad of the zone of maternal residence. By another infected new born sides whose mothers reside in zones of high endemicidad present/display, most frequently and of significant way, Apgar to 1 minute < to 7, low weight when being born and prematuridad or an association of these alterations with respiratory syndrome of distress or anasarca, when one compares them with new born of resident mothers in the zones of loss or medium endemicidad, mortality in this group is greater. These results suggest calls to account it of the mothers, in areas of high endemicidad, she is associate with a serious increase in the risk of Disease of newborn severe and mortal congenital Chagas in.

Maternal Trypanosoma cruzi infection upregulates capacity of uninfected neonate cells To produce pro- and anti-inflammatory cytokines.

The possibility of maternal in utero modulation of the innate and/or adaptive immune responses of uninfected newborns from Trypanosoma cruzi-infected mothers was investigated by studying the capacity of their whole blood cells to produce cytokines in response to T. cruzi lysate or lipopolysaccharide-plus-phytohemagglutinin (LPS-PHA) stimulation. Cells of such newborns occasionally released gamma interferon (IFN-gamma) and no interleukin-2 (IL-2) and IL-4 upon specific stimulation, while their mothers responded by the production of IFN-gamma, IL-2, and IL-4. Infection in mothers was also associated with a hyperactivation of maternal cells and also, strikingly, of cells of their uninfected neonates, since their release of proinflammatory (IL-1beta, IL-6, and tumor necrosis factor alpha [TNF-alpha]) as well as of anti-inflammatory (IL-10 and soluble TNF receptor) cytokines or factors was upregulated in the presence of LPS-PHA and/or parasite lysate. These results show that T. cruzi infection in mothers induces profound perturbations in the cytokine response of their uninfected neonates. Such maternal influence on neonatal innate immunity might contribute to limit the occurrence and severity of congenital infection.

In vitro promastigote fitness of putative Leishmania (Viannia) braziliensis/Leishmania (Viannia) peruviana hybrids.

In order to initiate studies on the phenotypic properties of hybrids vs. their putative parents, the in vitro growth behaviour of promastigotes was compared for 15 stocks characterised as Leishmania (Viannia) braziliensis, Leishmania (Viannia) peruviana and putative hybrids (isolated from the Eastern Andean valley of Huanuco, Peru). Five sets of three stocks, each set including a L.(V.)braziliensis, a L.(V.)peruviana and a putative hybrid, were constituted randomly and counted daily close to isolation from man (ten to 18 subcultures). Hybrids and L.(V.)peruviana presented similar growth characteristics, and they displayed a growth capacity (growth rate and cell density at stationary phase) significantly lower than the one of L.(V.)braziliensis. Following prolonged in vitro maintenance of one of the sets, the hybrid kept its lower growth capacity. The contrast between the difficulty to grow in vitro these putative hybrids, and their high isolation rate from natural populations is discussed.