scholarly journals Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi , the aetiological agent of Chagas disease

2015 ◽  
Vol 282 (1810) ◽  
pp. 20142807 ◽  
Author(s):  
Michael Z. Levy ◽  
Aaron Tustin ◽  
Ricardo Castillo-Neyra ◽  
Tarub S. Mabud ◽  
Katelyn Levy ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Guinea Pig ◽  
Chagas Disease ◽  
Domestic Animal ◽  
Infection Prevalence ◽  
Aetiological Agent ◽  
Force Of Infection ◽  
Animal Populations ◽  
Triatomine Bugs ◽  
High Infection

Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out.

Trypanosoma cruzi Infection Prevalence and Bloodmeal Analysis in Triatomine Vectors of Chagas Disease From Rural Peridomestic Locations in Texas, 2013–2014

2016 ◽  
Vol 53 (4) ◽  
pp. 911-918 ◽  
Author(s):  
Rodion Gorchakov ◽  
Lillian P. Trosclair ◽  
Edward J. Wozniak ◽  
Patricia T. Feria ◽  
Melissa N. Garcia ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Disease Surveillance ◽  
Public Awareness ◽  
Parasite Burden ◽  
Etiologic Agent ◽  
Infection Prevalence ◽  
Transmission Cycle ◽  
High Infection ◽  
History Of

Abstract Protozoan pathogen Trypanosoma cruzi (Chagas, 1909) is the etiologic agent of Chagas disease, which affects millions of people in Latin America. Recently, the disease has been gaining attention in Texas and the southern United States. Transmission cycle of the parasite involves alternating infection between insect vectors and vertebrate hosts (including humans, wildlife, and domestic animals). To evaluate vector T. cruzi parasite burden and feeding patterns, we tested triatomine vectors from 23 central, southern, and northeastern counties of Texas. Out of the 68 submitted specimens, the majority were genetically identified as Triatoma gerstaeckeri (Stal, 1859), with a few samples of Triatoma sanguisuga (LeConte, 1855), Triatoma lecticularia (Stal, 1859), Triatoma rubida (Uhler, 1894), and Triatoma protracta woodi (Usinger, 1939). We found almost two-thirds of the submitted insects were polymerase chain reaction-positive for T. cruzi. Bloodmeal sources were determined for most of the insects, and 16 different species of mammals were identified as hosts. The most prevalent type of bloodmeal was human, with over half of these insects found to be positive for T. cruzi. High infection rate of the triatomine vectors combined with high incidence of feeding on humans highlight the importance of Chagas disease surveillance in Texas. With our previous findings of autochthonous transmission of Chagas disease, urgent measures are needed to increase public awareness, vector control in and around homes, and Chagas screening of residents who present with a history of a triatomine exposure.

scholarly journals Dispersal patterns of Trypanosoma cruzi in Arequipa, Peru

2019 ◽  
Author(s):  
Alexander S.F. Berry ◽  
Renzo Salazar-Sánchez ◽  
Ricardo Castillo-Neyra ◽  
Katty Borrini-Mayorí ◽  
Claudia Arevalo-Nieto ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Causative Agent ◽  
Animal Movement ◽  
Protozoan Parasite ◽  
Domestic Animal ◽  
Urban Environments ◽  
Urban Landscapes ◽  
Population Genomic ◽  
The City

AbstractAnthropogenic environmental alterations such as urbanization can threaten native populations as well as create novel environments that allow human pests and pathogens to thrive. As the number and size of urban environments increase globally, it is more important than ever to understand the dispersal dynamics of hosts, vectors and pathogens of zoonotic disease systems. For example, a protozoan parasite and the causative agent of Chagas disease in humans, Trypanosoma cruzi, recently colonized and spread through the city of Arequipa, Peru. We used population genomic and phylogenomic tools to analyze whole genomes of 123 T. cruzi isolates collected throughout Arequipa to determine patterns of T. cruzi dispersal. The data show significant population genetic structure within city blocks-parasites in the same block tend to be very closely related - but no population structure among blocks within districts - parasites in neighboring blocks are no more closely related to one another than to parasites in distant districts. These data suggest that T. cruzi dispersal within a block occurs regularly and that occasional long-range dispersal events allow the establishment of new T. cruzi populations in distant blocks. Movement of domestic animals may be the primary mechanism of inter-block and inter-district T. cruzi dispersal.Author SummaryUrbanization creates environments that are ideal for some human pests and pathogens. As the number and size of urban environments increases globally, it is becoming vital to understand how human disease-causing pathogens, their vectors, and their non-human hosts disperse through urban landscapes. Here we study a population of Trypanosoma cruzi – the protozoan parasite and causative agent of Chagas disease in humans – that recently colonized the city of Arequipa, Peru. We use population genomic and phylogenomic tools to understand how this parasite population dispersed through the city to achieve its current distribution and abundance. We show that T. cruzi collected from the same city block tend to be very closely related, while those from neighboring blocks are often as distantly related as those from blocks in distant districts. The data suggest that vectors facilitate frequent within-block dispersal of the parasite, while domestic animal movement may facilitate the relatively infrequent inter-block and interdistrict dispersal.

scholarly journals The control of Latin American trypanosomiasis

1997 ◽  
Vol 30 (6) ◽  
pp. 521-527 ◽  
Author(s):  
Philip D. Marsden
Keyword(s):  
Latin America ◽  
Trypanosoma Cruzi ◽  
Disease Control ◽  
Chagas Disease ◽  
Latin American ◽  
Present Situation ◽  
Point Of View ◽  
American Trypanosomiasis ◽  
Triatomine Bugs ◽  
Latin America Countries

The author presents his personal point of view on the present situation of Chagas' disease control in Latin America countries. He compares the situation with African trypanosomiasis. He comments on the existence of cases in other Continents. He emphazises the success of the fighting against domiciliated triatomine bugs by using residual inseticides. He discusses other forms of Trypanosoma cruzi transmission.

scholarly journals Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease. 1 - Comparative xenodiagnosis with nine triatomine species of animals with acute infections by Trypanosoma cruzi

1982 ◽  
Vol 77 (1) ◽  
pp. 37-53 ◽  
Author(s):  
Alina Perlowagora-Szumlewicz ◽  
Carlos Alberto Muller
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Acute Infection ◽  
Geographical Area ◽  
Close Correlation ◽  
Triatoma Infestans ◽  
Infection Rates ◽  
Vector Species ◽  
Triatoma Sordida ◽  
High Infection

In search of a suitable vector species for xenodiagnosis of humans and animals with chronic Chagas' disease we first investigated the reactions of different vector species to acute infection with Trypanosoma cruzi. Vector species utilized in this study were: Triatoma infestans, Rhodnius prolixus and Triatoma dimidiata, all well adapted to human habitats; Triatoma rubrovaria and Rhodnius neglectus both considered totally wild species; Panstrongylus megistus, Triatoma sordida, Triatoma pseudomaculata and Triatoma brasiliensis, all essentially sylvatic but some with domiciliary tendencies and others restricted to peridomestic biotopes with incipient colonization of human houses after successful eradication of T. infestans. Results summarized in Table IV suggest the following order of infectivity among the 9 studied vector species: P. megistus with 97.8% of infected bugs, T. rubrovaria with 95% of positive bugs a close second followed by T. Pseudomaculata with 94.3% and R. neglectus with 93.8% of infected bugs, almost identical thirds. R. prolixus, T. infestans and T. dimidiata exhibited low infection rates of 53.1%, 51.6% and 38.2% respectively, coupled with sharp decreases occuring with aging of infection (Fig. 1). The situation was intermediate in T. brasiliensis and T. sordida infection rates being 76.9% and 80% respectively. Results also point to the existence of a close correlation between prevalence and intensity of infection in that, species with high infection rates ranging from 93.8% to 97.8% exhibited relatively large proportions of insects (27.3% - 33.5%) harbouring very dense populations of T. cruzi. In species with low infection rates ranging from 38.2% to 53.1% the proportion of bugs demonstrating comparable parasite densities was at most 6%. No differences attributable to blood-meal size or to greater susceptibility of indigenous vector species to parasites of their own geographical area, as suggested in earlier...

scholarly journals Hosts and vectors of Trypanosoma cruzi discrete typing units in the Chagas disease endemic region of the Paraguayan Chaco

Parasitology ◽  
2017 ◽  
Vol 144 (7) ◽  
pp. 884-898 ◽  
Author(s):  
NIDIA ACOSTA ◽  
ELSA LÓPEZ ◽  
MICHAEL D. LEWIS ◽  
MARTIN S. LLEWELLYN ◽  
ANA GÓMEZ ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Control Strategies ◽  
Triatoma Infestans ◽  
Effective Control ◽  
Primary Role ◽  
Endemic Region ◽  
Triatomine Bugs ◽  
Chaco Region ◽  
Euphractus Sexcinctus

SUMMARYActive Trypanosoma cruzi transmission persists in the Gran Chaco region, which is considered hyperendemic for Chagas disease. Understanding domestic and sylvatic transmission cycles and therefore the relationship between vectors and mammalian hosts is crucial to designing and implementing improved effective control strategies. Here we describe the species of triatomine vectors and the sylvatic mammal reservoirs of T. cruzi, in different localities of the Paraguayan and Bolivian Chaco. We identify the T. cruzi genotypes discrete typing units (DTUs) and provide a map of their geographical distribution. A total of 1044 triatomines and 138 sylvatic mammals were captured. Five per cent of the triatomines were microscopically positive for T. cruzi (55 Triatoma infestans from Paraguay and one sylvatic Triatoma guasayana from Bolivia) and 17 animals (12·3%) comprising eight of 28 (28·5%) Dasypus novemcinctus, four of 27 (14·8%) Euphractus sexcinctus, three of 64 (4·7%) Chaetophractus spp. and two of 14 (14·3%) Didelphis albiventris. The most common DTU infecting domestic triatomine bugs was TcV (64%), followed by TcVI (28%), TcII (6·5%) and TcIII (1·5%). TcIII was overwhelmingly associated with armadillo species. We confirm the primary role of T. infestans in domestic transmission, armadillo species as the principal sylvatic hosts of TcIII, and consider the potential risk of TcIII as an agent of Chagas disease in the Chaco.

scholarly journals Neue Parameter für die Wirkstofftestung gegen Trypanosoma cruzi

BIOspektrum ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 168-170
Author(s):  
Anna Fesser ◽  
Marcel Kaiser ◽  
Pascal Mäser
Keyword(s):  
Cell Culture ◽  
Latin America ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
New Drugs ◽  
High Content Imaging ◽  
Chronic Stage ◽  
Triatomine Bugs ◽  
And Migration

AbstractChagas disease is a zoonosis caused by Trypanosoma cruzi and transmitted by triatomine bugs. Autochthonous to Latin America, Chagas disease has spread globally through travel and migration. New drugs are needed urgently, in particular drugs that cure the chronic stage. This is where high-content imaging makes a key contribution: assays with fluorescent parasites in cell culture allow to determine pharmacodynamic parameters and to better assess the antichagasic potential of new molecules.

scholarly journals Elucidating the mechanism of Trypanosoma cruzi acquisition by triatomine insects: evidence from a large field survey of Triatoma infestans

2020 ◽  
Author(s):  
Aaron W. Tustin ◽  
Ricardo Castillo-Neyra ◽  
Laura D. Tamayo ◽  
Katty Borini-Mayorí ◽  
Renzo Salazar ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Control Strategies ◽  
Protozoan Parasite ◽  
Etiologic Agent ◽  
Triatoma Infestans ◽  
Large Field ◽  
Infection Prevalence ◽  
Percentage Points ◽  
Blood Sucking ◽  
Triatomine Bugs

AbstractBlood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated a linear relationship between infection prevalence and developmental stage. Prevalence increased by 5.4 percentage points with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.

scholarly journals Automated identification of insect vectors of Chagas disease in Brazil and Mexico: the Virtual Vector Lab

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3040 ◽  
Author(s):  
Rodrigo Gurgel-Gonçalves ◽  
Ed Komp ◽  
Lindsay P. Campbell ◽  
Ali Khalighifar ◽  
Jarrett Mellenbruch ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Disease Transmission ◽  
Automated System ◽  
Correct Identification ◽  
Insect Vectors ◽  
Automated Identification ◽  
Considerable Potential ◽  
Triatomine Bugs ◽  
Fully Automated System

Identification of arthropods important in disease transmission is a crucial, yet difficult, task that can demand considerable training and experience. An important case in point is that of the 150+ species of Triatominae, vectors ofTrypanosoma cruzi, causative agent of Chagas disease across the Americas. We present a fully automated system that is able to identify triatomine bugs from Mexico and Brazil with an accuracy consistently above 80%, and with considerable potential for further improvement. The system processes digital photographs from a photo apparatus into landmarks, and uses ratios of measurements among those landmarks, as well as (in a preliminary exploration) two measurements that approximate aspects of coloration, as the basis for classification. This project has thus produced a working prototype that achieves reasonably robust correct identification rates, although many more developments can and will be added, and—more broadly—the project illustrates the value of multidisciplinary collaborations in resolving difficult and complex challenges.

scholarly journals Distribution and natural infection status of synantrophic triatomines (Hemiptera: Reduviidae), vectors of Trypanosoma cruzi, reveals new epidemiological scenarios for chagas disease in the Highlands of Colombia

2021 ◽  
Vol 15 (7) ◽  
pp. e0009574
Author(s):  
Omar Cantillo-Barraza ◽  
Manuel Medina ◽  
Sara Zuluaga ◽  
María Isabel Blanco ◽  
Rodrigo Caro ◽  
...  
Keyword(s):  
Spatial Analysis ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Natural Infection ◽  
Significant Risk ◽  
Rhodnius Prolixus ◽  
The Other ◽  
Infection Status ◽  
Triatomine Bugs ◽  
Increased Risk

Introduction Updating the distribution and natural infection status of triatomine bugs is critical for planning, prioritizing, and implementing strategies to control Chagas disease (CD), especially after vector reduction programs. After carrying out a control program, the Department of Boyaca contains the highest number of Colombian municipalities certified by PAHO to be free of intradomiciliary transmission of Trypanosoma cruzi by Rhodnius prolixus. The present work describes the spatial distribution, natural infection (NI), and molecular characterization of T. cruzi in synanthropic triatomines from the Department of Boyaca in 2017 and 2018. Materials and methods An entomological survey was conducted in 52 municipalities in Boyaca known to have had previous infestations of triatomine bugs. Insects were collected through active searches carried out by technical personnel from the Secretary of Health and community members using Triatomine Collection Stations (PITs-acronym in Spanish). For evaluation of natural infection, triatomines were identified morphologically and grouped in pools of one to five individuals of the same species collected in the same household. DNA derived from the feces of each pool of insects was analyzed by PCR for the presence of T. cruzi using primers flanking the satellite DNA of the parasite. SL-IR primers were used to differentiate TCI from the other DTUs and to identify different genotypes. The distribution of the collected triatomines was analyzed to determine any vector hotspots using spatial recreation. Results A total of 670 triatomine bugs was collected, belonging to five species: Triatoma dimidiata (73.2%), Triatoma venosa (16.7%), Panstrongylus geniculatus (5.7%), Rhodnius prolixus (4.4%), and Panstrongylus rufotuberculatus (0.4%), from 29 of the 52 municipalities. In total, 71.6% of the bugs were collected within houses (intradomiciliary) and the rest around the houses (peridomiciliary). Triatoma dimidiata was the most widely distributed species and had the highest natural infection index (37.8%), followed by T. venosa and P. geniculatus. TcI was the only DTU found, with the TcI Dom genotype identified in 80% of positive samples and TcI sylvatic in the other insects. Spatial analysis showed clusters of T. dimidiata and T. venosa in the northeast and southwest regions of Boyaca. Conclusions After some municipalities were certified free of natural transmission within houses (intradomiciliary transmission) of T. cruzi by R. prolixus, T. dimidiata has become the most prevalent vector present, and represents a significant risk of resurgent CD transmission. However, T. venosa, P. geniculatus, and P. rufotuberculatus also contribute to the increased risk of transmission. The presence of residual R. prolixus may undo the successes achieved through vector elimination programs. The molecular and spatial analysis used here allows us to identify areas with an ongoing threat of parasite transmission and improve entomological surveillance strategies.

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