Apparent absence of Trypanosoma cruzi in Mexican free-tailed bats (Tadarida brasiliensis) from Texas, USA.

The Mexican free-tailed bat (Tadarida brasiliensis) is one of the most abundant mammals in North America. Mexican free-tailed bats have a wide geographic range stretching from northern South America to the western United States. Bats are theorized to be the original hosts for Trypanosoma cruzi -the causative agent of Chagas disease- and can serve as a source of infection to triatomine insect vectors that feed upon them. Chagas disease is a neglected tropical disease across the Americas where triatomines are present, including the southern United States, where Texas reports this highest number of locally-acquired human cases. To learn more about the role of bats in the ecology of Chagas disease in Texas, we surveyed a colony of Mexican free-tailed bats from Brazos County, Texas, for T. cruzi using carcasses salvaged after an extreme weather event. A total of 283 Mexican free-tailed bats collected in February 2021 were dissected and DNA from the hearts and kidneys was used for T. cruzi detection via qPCR. None of the bat hearts or kidneys tested positive for T. cruzi; this sample size affords 95% confidence that the true prevalence of T. cruzi in this population does not exceed 1%. Future sampling of multiple bat species as well as migrant and resident colonies of Mexican free-tailed bats across different times of the year over a broader geographic range would be useful in learning more about the role of bats in the ecology of Chagas disease in Texas.

Can infection with Trypanosoma cruzi modify the toxicological response of Triatoma infestans susceptible and resistant to deltamethrin?

Chemical control plays a central role in interrupting the vector transmission of Chagas disease. In recent years, high levels of resistance to pyrethroids have been detected in the main vector Triatoma infestans, which were associated with less effectiveness in chemical control campaigns in different regions of Argentina and Bolivia. The presence of the parasite within its vector can modify a wide range of insect physiological processes, including toxicological susceptibility and the expression of resistance to insecticides. This study examined for the first time the possible effects of Trypanosoma cruzi infection on susceptibility and resistance to deltamethrin in T. infestans. Using WHO protocol resistance monitoring assays, we exposed resistant and susceptible strains of T. infestans, uninfected and infected with T. cruzi to different concentrations of deltamethrin in fourth-instar nymphs at days 10-20 post-emergence and monitored survival at 24, 48, and 72 h. Our findings suggest that the infection affected the toxicological susceptibility of the susceptible strain, showing higher mortality than uninfected susceptible insects when exposed to both deltamethrin and acetone. On the other hand, the infection did not affect the toxicological susceptibility of the resistant strain, infected and uninfected showed similar toxic responses and the resistance ratios was not modified. This is the first report of the effect of T. cruzi on the toxicological susceptibility of T. infestans and triatomines in general and, to our knowledge, one of the few on the effect of a parasite on the insecticide susceptibility of its insect vector.

Diagnóstico de la Enfermedad de Chagas congénito: Aspectos relevantes

Introducción: El presente artículo describe aspectos relevantes entorno de la Enfermedad de Chagas congénita, tales como epidemiología, sintomatología, revisión de casos clínicos y las técnicas diagnósticas. Métodos: Se realizó una revisión de la literatura por medio de bases de datos bibliográficas como PubMed, Science direct, Scopus, Plos One, SciELO, teniendo como criterio de inclusión las publicaciones artículos o comprendidos entre enero de 2013 y enero del año 2022 en idioma español e inglés. Resultados: Se determinó que la prevalencia de la Enfermedad de Chagas congénita aún es un problema de salud pública en áreas endémicas y no endémicas, siendo la serología materna indispensable para dar seguimiento oportuno a los casos. Conclusiones: Los seguimientos diagnósticos actuales difieren en los países endémicos y se están aplicando tamizajes en zonas no endémicas donde migran mujeres procedentes de áreas de trasmisión activa de la Enfermedad Chagásica.

Introduction: This article describes relevant aspects of congenital Chagas disease, such as epidemiology, symptoms, review of clinical cases, and diagnostic techniques. Methods: A review of the literature was carried out through bibliographic databases such as PubMed, Science direct, Scopus, Plos One, SciELO, having as inclusion criteria articles or publications between January 2013 and January 2022 in Spanish and English. Results: It was determined that the prevalence of congenital Chagas disease is still a public health problem in endemic and non-endemic areas, and maternal serology is essential for timely monitoring of cases. Conclusions: Current diagnostic follow-ups differ in endemic countries and screening is being applied in non-endemic areas where women from areas of active transmission of Chagasic disease migrate.

Caracterização epidemiológica e distribuição geográfica de potenciais vetores da doença de Chagas na região do Maciço de Baturité, Ceará, Brasil / Epidemiological characterization and geographical distribution of potential vectors of Chagas Disease in Maciço Baturité region, Ceara, Brazil

Objetivo: identificar potenciais vetores da doença de Chagas na região do Maciço de Baturité, Ceará. Métodos: no período de2014 a 2018, foi realizado estudo parasitológico em fezes de triatomíneos para Trypanosoma cruzi, em oito municípios da região do maciço de Baturité. Os triatomíneos foram capturados em ambiente intradomiciliar e peridomiciliar. Resultados: foram examinados 594 vetores, a diagnose revelou infecção natural por Trypanosoma cruzi em 79 (13,3%) espécimes, sendo, 53 machos (8,9%), 25 fêmeas (4,2%) e 1 ninfa (0,2%). Conclusão: os resultados evidenciam a região como endêmica para doença de Chagas com sete casos humanos confirmados em três municípios, existindo vários focos silenciosos em que pode haver a transmissão do agente etiológico.

Objective: to identify potential vectors of Chagas disease in the Baturité Massif region, Ceará Methods: during the period from 2014 to 2018, a parasitological study was performed on triatomine feces for Trypanosoma cruzi, in eight municipalities in Maciço Baturité region. Triatomines were captured indoors and peridomiciliary by endemic agents and population as well. Results: a total of594 vectors were examined, diagnosis revealed natural infection by Trypanosoma cruzi in79 (13,3%) specimens, being, 53 males (8,9%), 25 females (4,2%) and 1 nymph (0,2%). Conclusion: results evidenced the region as endemic to Chagas Disease with seven confirmed human cases in three municipalities with several silent foci where the causative agent might be transmitted.

Pep5, a fragment of Cyclin D2, shows antiparasitic effects in different stages of the Trypanosoma cruzi life cycle and blocks parasite infectivity

Pep5 (WELVVLGKL) is a fragment of cyclin D2 that exhibits a 2-fold increase in the S phase of the HeLa cell cycle. When covalently bound to a cellpenetrating peptide (Pep5-cpp), the nonapeptide induces cell death in several tumor cells, including breast cancer and melanoma cells. Additionally, Pep5-cpp reduces the in vivo tumor volume of rat glioblastoma. Chagas disease, which is caused by the flagellated parasite Trypanosoma cruzi, is a neglected disease that occurs mainly in the Americas, where it is considered an important public health issue. Given that there are only two options for treating the disease, it is exceptionally crucial to search for new molecules with potential pharmacological action against the parasites. In this study, we demonstrate that Pep5-cpp induces cell death in epimastigote, trypomastigote, and amastigote forms of T. cruzi. The Pep5-cpp peptide was also able to decrease the percentage of infected cells without causing any detectable toxic effects in mammalian host cells. The infective, i.e., trypomastigote form of T. cruzi pretreated with Pep5-cpp was unable to infect LLC-MK2 monkey kidney cells. Also, Pep5-binding proteins were identified by mass spectrometry, including calmodulinubiquitin-associated protein, which is related to the virulence and parasitemia of T. cruzi. Taken together, these data suggest that Pep5 can be used as a novel alternative for the treatment of Chagas disease.

Trypanosoma cruzi over the ocean: Insular zones of Chile with presence of infected vector Mepraia species.

Chagas disease is one of the main zoonosis mediated by vectors in America. The etiologic agent Trypanosoma cruzi infects different mammals and is transmitted principally by the subfamily Triatominae. Mepraia is a genus endemic to Chile, responsible for transmitting T. cruzi in the sylvatic cycle. Mepraia includes three species: M. gajardoi and M. parapatrica inhabit coastal areas, while M. spinolai inhabits coastal and interior valleys. Previous studies reported the occurrence of Mepraia in Pan de Azucar Island, currently classified as M. parapatrica, but T. cruzi has not been reported in these insects. It is suggested that this could be due to infrequent insect feeding on mammalian hosts. In order to detect T. cruzi in insects from coastal islands, specimens from Pan de Azucar and Santa Maria Islands were examined. A region of kDNA of T. cruzi was amplified by PCR and hybridization assays were performed for T. cruzi genotyping of insect feces. The presence of infected insect and mixed T. cruzi infections was demonstrated. This is the first report of infected Triatominae in coastal islands in Chile. We discuss T. cruzi detection in insular zones, and the presumptive reservoirs that may participate in maintaining its transmission cycle in this habitat. Mixed and unidentified infections suggest that there are complex and unknown reservoir interactions in these habitats.

Triatominos (Hemiptera: Reduviidae) de la sierra nevada de santa marta, colombia. Aspectos epidemiológicos, Entosmológicos y de distribución / Triatominae (Hemiptera: Reduviidae) in the Sierra Nevada of Santa Marta, Colombia. Epidemiological, entomological and distributional aspects

Se coleccionaron 207 insectos pertenecientes a cinco especies: Triatoma maculata, Panstrongylus geniculatus, Rhodnius prolixus, T. dimidiata y R. pallescens. R. prolixus y T. dimidiata fueron las especies con los indicadores entomológicos de infestación de viviendas, colonización, dispersión e infección triatomínica más importantes; así mismo predominaron en todas las colecciones, considerándose las especies con mayor importancia epidemiológica en la zona de estudio. El 82% de todas las especies de triatominos fueron capturados en ambientes intradomiciliarios. Adicionalmente, se amplía la distribución geográfica de R. pallescens. Conclusiones: Estos hallazgos sumados a la alta seroprevalencia para T. cruzi en la región, permiten concluir que la Sierra Nevada de Santa Marta es una zona de alto riesgo de transmisión de la enfermedad de Chagas.

Objective: To describe tne entomological indexes and epidemiological importance of triatomines (Hemiptera: Reduviidae) of tne north and east slope of Santa Marta's Sierra Nevada. Colombia. Methods: Cross-sectional descriptive study. Sampling was done in 196 indigenous nuts of seven towns. Triatomines collections were done inside nouses and in peridomestic areas. Results: A total of 207 triatomines belonging to five species: Triatoma maculata, Panstrongylus geniculatus, Rnodnius prolixus. T. dimidiata and R. pallescens. was collected. R. prolixus and T. dimidiata was the species witn tne most important entomological indexes of house infestation, colonization, dispersion and infection predominating in all collections, and are considered the most epidemiological important species in the area. 82% of all triatomine species were collected inside houses. Additionally, geographical distribution of R. pallescens is extended. Conclusions: Present reports plus high prevalence found in the zone allow us to conclude that Santa Martas' Sierra Nevada is of high risk for Chaga's disease transmission.