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Journal of Wildlife Diseases Oct 2023Chagas disease, a significant public health concern in the Americas, is caused by a protozoan parasite, Trypanosoma cruzi. The life cycle of T. cruzi involves kissing...
Chagas disease, a significant public health concern in the Americas, is caused by a protozoan parasite, Trypanosoma cruzi. The life cycle of T. cruzi involves kissing bugs (Triatoma spp.) functioning as vectors and mammalian species serving as hosts. Raccoons (Procyon lotor) and opossums (Didelphis virginiana) have been identified as important reservoir species in the life cycle of T. cruzi, but prevalence in both species in the southeastern US is currently understudied. We quantified T. cruzi prevalence in these two key reservoir species across our study area in South Carolina, US, and identified factors that may influence parasite detection. We collected whole blood from 183 raccoons and 126 opossums and used PCR to detect the presence of T. cruzi. We then used generalized linear models with parasite detection status as a binary response variable and predictor variables of land cover, distance to water, sex, season, and species. Our analysis indicated that raccoons experienced significantly higher parasite detection rates than Virginia opossums, with T. cruzi prevalence found to be 26.5% (95% confidence interval [CI], 20.0-33.8) in raccoons and 10.5% (95% CI, 5.51-17.5) in opossums. Overall, our results concur with previous studies, in that T. cruzi is established in reservoir host populations in natural areas of the southeastern US.
Topics: Animals; Trypanosoma cruzi; Didelphis; Raccoons; South Carolina; Virginia; Chagas Disease; Opossums; Triatoma
PubMed: 37846907
DOI: 10.7589/JWD-D-22-00174 -
PLoS Neglected Tropical Diseases Oct 2023Vector-borne diseases remain a significant public health threat in many regions of the world. Traditional vector surveillance and control methods have relied on active...
Vector-borne diseases remain a significant public health threat in many regions of the world. Traditional vector surveillance and control methods have relied on active and passive surveillance programs, which are often costly and time-consuming. New internet-based vector surveillance systems have shown promise in removing some of the cost and labor burden from health authorities. We developed and evaluated the effectiveness of a new internet-based surveillance system, "AlertaChirimacha", for detecting Triatoma infestans (known locally by its Quechua name, Chirimacha), the Chagas disease vector, in the city of Arequipa, Peru. In the first 26 months post-implementation, AlertaChirimacha received 206 reports of residents suspecting or fearing triatomines in their homes or neighborhoods, of which we confirmed, through pictures or inspections, 11 (5.3%) to be Triatoma infestans. After microscopic examination, none of the specimens collected were infected with Trypanosoma cruzi. AlertaChirimacha received 57% more confirmed reports than the traditional surveillance system and detected 10% more infested houses than active and passive surveillance approaches combined. Through in-depth interviews we evaluate the reach, bilateral engagement, and response promptness and efficiency of AlertaChirimacha. Our study highlights the potential of internet-based vector surveillance systems, such as AlertaChirimacha, to improve vector surveillance and control efforts in resource-limited settings. This approach could decrease the cost and time horizon for the elimination of vector-mediated Chagas disease in the region.
Topics: Animals; Humans; Chagas Disease; Triatoma; Trypanosoma cruzi; Insect Vectors; Peru
PubMed: 37844066
DOI: 10.1371/journal.pntd.0011694 -
Journal of Vector Ecology : Journal of... Dec 2023
Topics: Animals; Triatominae; Triatoma; Trypanosoma cruzi; Brazil; Chagas Disease
PubMed: 37843456
DOI: 10.52707/1081-1710-48.2.138 -
Journal of Vector Ecology : Journal of... Dec 2023Triatominae are associated with various Brazilian habitats, including bird nests, animal burrows, and peridomestic structures. Despite extensive studies on triatomines...
Triatominae are associated with various Brazilian habitats, including bird nests, animal burrows, and peridomestic structures. Despite extensive studies on triatomines in domiciliary environments in Ceará, Brazil, there has been limited research on their presence in the wild. This study focuses on the municipality of Morrinhos in Ceará, which is characterized by a Caatinga biome and riparian forests along the Acaraú River. During the study, a total of 185 nests of were analyzed in rural locations and triatomines were collected in 26 nests from 12 different locations. A total of 117 triatomines was collected, belonging to three species: , , and . was the only species found in a nest inhabited by . Nests of serve as shelters for various animals, providing an ideal environment for triatomines to establish colonies due to their proximity to food sources and their generalist feeding habits. The incorporation of anthropogenic materials by birds in nest construction can indirectly affect the presence of other animals that may serve as food sources for triatomines. Understanding the interactions between triatomines, birds, and their habitats is essential for assessing the risks associated with triatomine infestation in wild ecosystems.
Topics: Animals; Triatominae; Brazil; Ecosystem; Insect Vectors; Triatoma; Rhodnius; Birds; Chagas Disease; Trypanosoma cruzi
PubMed: 37843454
DOI: 10.52707/1081-1710-48.2.124 -
Journal of Vector Ecology : Journal of... Dec 2023Chagas disease is one of the most important vector-borne diseases in Latin America. (Usinger), distributed in western Mexico, is one of the most important vectors of...
Chagas disease is one of the most important vector-borne diseases in Latin America. (Usinger), distributed in western Mexico, is one of the most important vectors of Chagas. Knowing the type and materials used for building homes could lead to improved methods for controlling triatomines by focusing efforts on controlling every species of triatomine in its specific microhabitat. Houses in three studied localities of western Mexico that harbored were characterized, as well as two entomological indices. Infestation Index values varied from 10.8% to 51.9% in the three localities, whereas Natural Infection Index values varied from 18.1% to 35.2%. Characteristics of houses invaded by also varied. In Juan Gil Preciado, with the highest Entomological Index values, most houses were built of adobe walls with a roof of clay tiles and a dirt floor, and included the presence of domestic animals. Our data indicate that the potential risk of infection with differs markedly for inhabitants of the three studied localities, which demonstrates the importance of studying local populations of triatomines. Our study should contribute to decision-making regarding triatomine control efforts by providing profiles of houses that are more susceptible to triatomine invasion.
Topics: Humans; Animals; Triatoma; Trypanosoma cruzi; Mexico; Insect Vectors; Chagas Disease; Ecosystem
PubMed: 37843448
DOI: 10.52707/1081-1710-48.2.66 -
Frontiers in Endocrinology 2023Within insects, corticotropin-releasing factor/diuretic hormones (CRF/DHs) are responsible for the modulation of a range of physiological and behavioural processes such...
Within insects, corticotropin-releasing factor/diuretic hormones (CRF/DHs) are responsible for the modulation of a range of physiological and behavioural processes such as feeding, diuresis, and reproduction. Rhopr-CRF/DH plays a key role in feeding and diuresis in , a blood-gorging insect and a vector for human Chagas disease. Here, we extend our understanding on the role of this neurohormone in reproduction in adult female . Double-label immunohistochemistry displays co-localized staining of CRF-like and the glycoprotein hormone (GPA2/GPB5) subunit GPB5-like immunoreactivity in the same neurosecretory cells (NSCs) in the mesothoracic ganglionic mass (MTGM) and in their neurohemal sites in adult female , suggesting these peptides could work together to regulate physiological processes. qPCR analysis reveals that the transcript for Rhopr-CRF/DH receptor 2 () is expressed in reproductive tissues and fat body (FB) in adult female , and its expression increases post blood meal (PBM), a stimulus that triggers diuresis and reproduction. Using RNA interference, transcript expression of was knocked down, and egg production monitored by examining the major yolk protein, vitellogenin (Vg), the number and quality of eggs laid, and their hatching ratio. Injection of dsCRFR2 into adult females reduces transcript expression, accelerates oogenesis, increases the number of eggs produced, and reduces hatching rate in female . Downregulation of leads to an increase in the transcript expression of in the fat body and ovaries, and increases the transcript level for the Vg receptor, , in the ovaries. A significant increase in Vg content in the fat body and in the hemolymph is also observed. Incubation of isolated tissues with Rhopr-CRF/DH leads to a significant decrease in transcript expression of in the fat body and in the ovaries. In addition, Rhopr-CRF/DH reduces transcript expression of the ecdysteroid biosynthetic enzymes and reduces ecdysteroid titer in the culture medium containing isolated ovaries. These results suggest the involvement of the CRF-signaling pathway in reproduction, and that Rhopr-CRF/DH acts as a gonad-inhibiting hormone in the adult female , as previously shown for the colocalized glycoprotein, GPA2/GPB5.
Topics: Animals; Female; Adult; Humans; Corticotropin-Releasing Hormone; Diuretics; Rhodnius; Ecdysteroids; Gonadal Hormones; Glycoproteins; Gonads
PubMed: 37842303
DOI: 10.3389/fendo.2023.1279929 -
Current Research in Parasitology &... 2023Triatomines (Hemiptera: Reduviidae: Triatominae), commonly called "kissing bugs", are blood-sucking pests and vectors of the protozoan parasite , the causative agent of... (Review)
Review
Triatomines (Hemiptera: Reduviidae: Triatominae), commonly called "kissing bugs", are blood-sucking pests and vectors of the protozoan parasite , the causative agent of Chagas disease (CD). Eleven species of kissing bugs occur throughout the southern half of the USA, four of which are well known to invade human dwellings. Certain kissing bugs in the USA are known to transmit to humans and other animals and their bites can also lead to serious allergic reactions, including anaphylaxis. In Florida, the kissing bug frequently invades homes, bites residents, and has been found infected with , placing humans and companion animals at risk for CD. This review outlines integrated pest management (IPM) strategies for minimizing human exposure to and CD. A comprehensive IPM plan for kissing bugs includes detailed inspections, removal of vertebrate host nesting areas, and kissing bug harborage, home improvements to exclude kissing bugs from entering structures, pest removal, and judicious use of pesticides. This approach can limit or eliminate kissing bug entry into residential structures, thereby preventing kissing bug bites, and CD infections in humans and companion animals.
PubMed: 37841307
DOI: 10.1016/j.crpvbd.2023.100144 -
ZooKeys 2023is described. Taxonomic notes on the other species of Barber, 1930, including the description of their male genitalia, are provided. The record of Barber, 1930 from...
A new species of Barber, with a redescription of the genus, taxonomic notes, and a key to the species of the genus (Hemiptera, Heteroptera, Reduviidae, Stenopodainae).
is described. Taxonomic notes on the other species of Barber, 1930, including the description of their male genitalia, are provided. The record of Barber, 1930 from Brazil and information about the female of the species are presented for the first time. A redescription of and a key for its species are provided. Photographs of the holotypes of (Costa Lima, 1941), , and of a paratype of Maldonado & Bérenger, 1996 are presented.
PubMed: 37841028
DOI: 10.3897/zookeys.1181.108463 -
Acta Tropica Dec 2023In the Yucatan Peninsula, Mexico, Triatoma dimidiata is the main vector of Chagas disease. This is a native species in the region that principally inhabits sylvatic...
In the Yucatan Peninsula, Mexico, Triatoma dimidiata is the main vector of Chagas disease. This is a native species in the region that principally inhabits sylvatic habitats. Nevertheless, it shows a tolerant behavior to anthropogenic disturbance, with adult bugs frequently infesting human dwellings, principally during the warm and dry season. Yet, whether the temporal variation of abundance is independent of the habitat and how this is related to the infection rate with Trypanosoma cruzi in Yucatan is still poorly understood. The objective of this study was to simultaneously analyze the temporal variations of T. dimidiata abundance and infection with T. cruzi in domestic and sylvatic habitats from two localities of rural Yucatan (Sudzal, 20°52'19″N, 88°59'20″W and Teya, 21°02'55″N, 89°04'25″W) to help for the further improvement of locally adapted strategies aimed at controlling T. cruzi vector transmission. Using community participation and a combination of different trapping techniques, we collected T. dimidiata bugs during 29 consecutive months within domestic and sylvatic habitats. We then assessed by PCR the infection of the bugs with T. cruzi. Generalized linear models were used to evaluate the effect of climatic variables on the abundance of T. dimidiata and the effect of bug sex, season and habitat on the prevalence of infection with T. cruzi. Overall, 3640 specimens of T. dimidiata were collected. We clearly observed peaks of maximum abundance in both habitats during the warm and dry season and found a negative association of bug abundance with relative humidity. The overall prevalence of infection of the bugs with T. cruzi was 15.2 %. Additionally, bugs collected in domestic habitats displayed a significantly higher prevalence of infection than sylvatic bugs (19.6% vs. 6.1 %, respectively), suggesting an increased risk of T. cruzi transmission related with anthropogenic disturbance. Our study is the first to describe the annual pattern of abundance of T. dimidiata in sylvatic habitats of rural Yucatan and constitutes a contribution to the knowledge of T. dimidiata ecology and of T. cruzi transmission cycle dynamics in the region. In Yucatan, where the use of mosquito nets has shown to be effective to limit human dwelling infestation by T. dimidiata, reinforcing the awareness of local residents about the increased risk of T. cruzi transmission during the warm and dry season when realizing activities in the sylvatic ambient should be, among others, also considered to improve control strategies and limit the risk of vector transmission.
Topics: Animals; Humans; Triatoma; Trypanosoma cruzi; Mexico; Chagas Disease; Ecosystem
PubMed: 37839668
DOI: 10.1016/j.actatropica.2023.107038 -
Acta Tropica Dec 2023The proximity between infectious disease vector populations and human settlements, and the infection prevalence of vector populations can determine the rate of...
The proximity between infectious disease vector populations and human settlements, and the infection prevalence of vector populations can determine the rate of encounters between vectors and humans and hence infection risk. The diet of sylvatic triatomine vectors (kissing bugs) provides evidence about the host species involved in the maintenance of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Here, we characterized the diet of the Chilean endemic triatomine Mepraia spinolai using Next Generation Sequencing (NGS), and evaluated the relation between T. cruzi infection status and proximity to human settlements, with the proportion of human and human-associated (domestic and synanthropic) vertebrates in the diet. We sampled 28 M. spinolai populations, covering a latitudinal range of ∼800 km in Chile. For each population, genomic DNA was obtained from M. spinolai intestinal content. We assessed T. cruzi infection individually, and sequenced vertebrate cytochrome b to characterize the diet from infected and uninfected pooled samples. Human and human-associated animals were present in the diet of both T. cruzi-infected (13.50 %) and uninfected (10.43 %) kissing bugs. The proportion of human and human-associated vertebrates in the diet of infected M. spinolai was negatively associated with the distance from surrounding human settlements, but no relationship was detected for uninfected kissing bugs. This pattern could be related to alterations of kissing bug feeding behavior when infected by the protozoan. Our results highlight the relevance of developing a deeper knowledge of the wild transmission cycle of T. cruzi, thus advancing in the surveillance of vectors present in the natural environment near human settlements.
Topics: Animals; Humans; Chagas Disease; Triatominae; Trypanosoma cruzi; Diet; Triatoma
PubMed: 37839667
DOI: 10.1016/j.actatropica.2023.107039