Chagas disease is a neglected tropical disease transmitted by the protozoan Trypanosoma cruzi that lately has been highlighted because several outbreaks attributed to oral transmission of the ...parasite have occurred. These outbreaks are characterized by high mortality rates and massive infections that cannot be related to other types of transmission such as the vectorial route. Oral transmission of Chagas disease has been reported in Brazil, Colombia, Venezuela, Bolivia, Ecuador, Argentina and French Guiana, most of them are massive oral outbreaks caused by the ingestion of beverages and food contaminated with triatomine feces or parasites’ reservoirs secretions and considered since 2012 as a foodborne disease. In this review, we present the current status and all available data regarding oral transmission of Chagas disease, highlighting its relevance as a veterinary and medical foodborne zoonosis.
•Trypanosoma cruzi oral transmission is highlighted as an emerging food-borne diseases.•Many questions remain regarding the biology of oral transmission.•We herein compiled the historical outbreaks of oral outbreaks in the Americas.
Abstract
Chagas disease caused by
Trypanosoma cruzi
is a public health issue in Latin America. This highly diverse parasite is divided into at least seven discrete typing units (DTUs) TcI-TcVI and ...Tcbat. Some DTUs have been associated with geographical distribution in epidemiological scenarios and clinical manifestations, but these aspects remain poorly understood. Many studies have focused on studying the parasite and its vectors/hosts, using a wide variety of genetic markers and methods. Here, we performed a systematic review of the literature for the last 20 years to present an update of DTUs distribution in the Americas, collecting ecoepidemiological information. We found that the DTUs are widespread across the continent and that there is a whole gamma of genetic markers used for the identification and genotyping of the parasite. The data obtained in this descriptor could improve the molecular epidemiology studies of Chagas disease in endemic regions.
Triatomines (Hemiptera: Reduviidae) are the insect vectors of Trypanosoma cruzi, the causative agent of Chagas disease. The gut bacterial communities affect the development of T. cruzi inside the ...vector, making the characterization of its composition important in the understanding of infection development. We collected 54 triatomine bugs corresponding to four genera in different departments of Colombia. DNA extraction and PCR were performed to evaluate T. cruzi presence and to determine the discrete typing unit (DTU) of the parasite. PCR products of the bacterial 16S rRNA gene were pooled and sequenced. Resulting reads were denoised and QIIME 2 was used for the identification of amplicon sequence variants (ASVs). Diversity (alpha and beta diversity) and richness analyses, Circos plots, and principal component analysis (PCA) were also performed. The overall T. cruzi infection frequency was 75.9%, with TcI being the predominant DTU. Approximately 500,000 sequences were analyzed and 27 bacterial phyla were identified. The most abundant phyla were Proteobacteria (33.9%), Actinobacteria (32.4%), Firmicutes (19.6%), and Bacteroidetes (7.6%), which together accounted for over 90% of the gut communities identified in this study. Genera were identified for these main bacterial phyla, revealing the presence of important bacteria such as Rhodococcus, Serratia, and Wolbachia. The composition of bacterial phyla in the gut of the insects was significantly different between triatomine species, whereas no significant difference was seen between the state of T. cruzi infection. We suggest further investigation with the evaluation of additional variables and a larger sample size. To our knowledge, this study is the first characterization of the gut bacterial structure of the main triatomine genera in Colombia.
Triatomines are hematophagous insects that play an important role as vectors of Trypanosoma cruzi, the causative agent of Chagas disease. These insects have adapted to multiple blood-feeding sources ...that can affect relevant aspects of their life-cycle and interactions, thereby influencing parasitic transmission dynamics. We conducted a characterization of the feeding sources of individuals from the primary circulating triatomine genera in Colombia using amplicon-based next-generation sequencing (NGS).
We used 42 triatomines collected in different departments of Colombia. DNA was extracted from the gut. The presence of T. cruzi was identified using real-time PCR, and discrete typing units (DTUs) were determined by conventional PCR. For blood-feeding source identification, PCR products of the vertebrate 12S rRNA gene were obtained and sequenced by next-generation sequencing (NGS). Blood-meal sources were inferred using blastn against a curated reference dataset containing the 12S rRNA sequences belonging to vertebrates with a distribution in South America that represent a potential feeding source for triatomine bugs. Mean and median comparison tests were performed to evaluate differences in triatomine blood-feeding sources, infection state, and geographical regions. Lastly, the inverse Simpson's diversity index was calculated.
The overall frequency of T. cruzi infection was 83.3%. TcI was found as the most predominant DTU (65.7%). A total of 67 feeding sources were detected from the analyses of approximately 7 million reads. The predominant feeding source found was Homo sapiens (76.8%), followed by birds (10.5%), artiodactyls (4.4%), and non-human primates (3.9%). There were differences among numerous feeding sources of triatomines of different species. The diversity of feeding sources also differed depending on the presence of T. cruzi.
To the best of our knowledge, this is the first study to employ amplicon-based NGS of the 12S rRNA gene to depict blood-feeding sources of multiple triatomine species collected in different regions of Colombia. Our findings report a striking read diversity that has not been reported previously. This is a powerful approach to unravel transmission dynamics at microgeographical levels.
Chagas disease is considered a public health issue in Colombia, where many regions are endemic.
Triatoma dimidiata
is an important vector after
Rhodnius prolixus
, and it is gaining importance in ...Boyacá, eastern Colombia. Following the recent elimination of
R
.
prolixus
in the region, it is pivotal to understand the behavior of
T
.
dimidiata
and the transmission dynamics of
T
.
cruzi
. We used qPCR and Next Generation Sequencing (NGS) to evaluate
T
.
cruzi
infection, parasite load, feeding profiles, and
T
.
cruzi
genotyping for
T
.
dimidiata
specimens collected in nine municipalities in Boyacá and explored
T
.
dimidiata
population genetics. We found that
T
.
dimidiata
populations are composed by a single population with similar genetic characteristics that present infection rates up to 70%, high parasite loads up to 1.46 × 10
9
parasite-equivalents/mL, a feeding behavior that comprises at least 17 domestic, synanthropic and sylvatic species, and a wide diversity of TcI genotypes even within a single specimen. These results imply that
T
.
dimidiata
behavior is similar to other successful vectors, having a wide variety of blood sources and contributing to the circulation of different genotypes of the parasite, highlighting its importance for
T
.
cruzi
transmission and risk for humans. In the light of the elimination of
R
.
prolixus
in Boyacá and the results we found, we suggest that
T
.
dimidiata
should become a new target for vector control programs. We hope this study provides enough information to enhance surveillance programs and a future effective interruption of
T
.
cruzi
vector transmission in endemic regions.
Chagas disease, affecting approximately eight million individuals in tropical regions, is primarily transmitted by vectors. Rhodnius prolixus, a triatomine vector, commonly inhabits in ecotopes with ...diverse palm tree species, creating optimal conditions for vector proliferation. This study aims to explore the transmission ecology of Trypanosoma cruzi, the causative parasite of Chagas disease, by investigating the feeding patterns and natural infection rates of R. prolixus specimens collected from various wild palm species in the Colombian Orinoco region.
To achieve this objective, we sampled 35 individuals from three palm species (Attalea butyracea, Acrocomia aculeata, and Mauritia flexuosa) in a riparian forest in the Casanare department of eastern Colombia, totaling 105 sampled palm trees. DNA was extracted and analyzed from 115 R. prolixus specimens at different developmental stages using quantitative PCR (qPCR) for T. cruzi detection and identification of discrete typing units. Feeding preferences were determined by sequencing the 12S rRNA gene amplicon through next-generation sequencing.
A total of 676 R. prolixus specimens were collected from the sampled palms. The study revealed variation in population densities and developmental stages of R. prolixus among palm tree species, with higher densities observed in A. butyracea and lower densities in M. flexuosa. TcI was the exclusive T. cruzi discrete typing unit (DTU) found, with infection frequency positively correlated with R. prolixus abundance. Insects captured in A. butyracea exhibited higher abundance and infection rates than those from other palm species. The feeding sources comprised 13 mammal species, showing no significant differences between palm species in terms of blood sources. However, Didelphis marsupialis and Homo sapiens were present in all examined R. prolixus, and Dasypus novemcinctus was found in 89.47% of the insects.
This study highlights the significance of wild palms, particularly A. butyracea, as a substantial risk factor for T. cruzi transmission to humans in these environments. High population densities and infection rates of R. prolixus were observed in each examined palm tree species.
Chagas disease (CD) is a parasitic zoonosis (
that is endemic in Colombia. Vector control of
, the main domestic
vector, has been achieved in a large part of the area with historically vector ...transmission of CD. It is necessary to understand the ecological behavior characteristics of local native vectors to ensure sustainability of the vector control programs. To evaluate the long-term success of a recent vector control campaign in the Boyacá department (Colombia), we used a combined strategy of entomological surveillance with co-existing canine surveillance from ten rural villages within six municipalities of the Tenza valley region (Boyacá, Colombia): Chinavita, Garagoa, Guateque, Somondoco, Sutatenza and Tenza, with historical reports of
and secondary vectors. Collected triatomines and canine whole blood were analyzed for
infection and genotyping. Triatomine bugs specimens were evaluated for blood meal source. Canine serology was performed using two distinct antibody assays. In total, 101
were collected by active search in domestic and peridomestic habitats. A natural infection prevalence of 13.9% (14/101) and four feeding sources were identified: human, dog, rat, and hen. A frequency infection of 46.5% (40/87) was observed from two independent serological tests and
DNA was detected in 14 dogs (16.4%). Only TcI
DTU was detected. The results suggest that
present eco-epidemiological characteristics to maintain the transmission of
in Tenza valley. This species has reinfested the intervened households and it has an active role in domestic and peridomestic transmission of
due to their infection rates and feeding behavior. Therefore, this species should be considered as epidemiologically relevant for vector control strategies. Moreover, there is a need for human serological studies to have a close up of risk they are exposed to.
'Trypanosoma cruzi', the causal agent of Chagas disease, is mainly transmitted by insects of the Triatominae subfamily. In Colombia, there are 26 triatomine species, and 16 of them are naturally ...infected with the parasite. The parasite loads of naturally infected vectors can be significant in targeting specific species that can affect the epidemiology of the disease. Studying their ecology and behavior is vital to understand their role in 'T. cruzi' transmission dynamics. We evaluated the parasite loads of 182 field-collected triatomines corresponding to 10 species in 13 departments across Colombia. We standardized a methodology to quantify 'T. cruzi' DNA in these insects. We obtained a LOD (limit of detection) of 3.05 p-eq/mL. The 82% of triatomines we evaluated were positive for 'T. cruzi' infection, with loads ranging from hundreds to millions of equivalent parasites per milliliter. 'Panstrongylus geniculatus', 'Rhodnius prolixus', and 'Triatoma dimidiata' were the species with the highest loads of 'T. cruzi'; however, other species whose role as vectors is still unknown were also found with high loads of parasites. Our results suggest the relevance of secondary species for 'T. cruzi' transmission in Colombia. We hope our data can help improve entomological surveillance and vector control programs in the country and the region.
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•Blood source analysis shows complex interactions in diverse habitats favoring pathogen transmission in disturbed environments.•Significant correlations were found between Rhodnius ...prolixus and specific environments.•Adult insects exhibit higher parasitic loads in dwelling and pasture habitats.
Chagas disease affects millions of people in Colombia and worldwide, with its transmission influenced by ecological, environmental, and anthropogenic factors. There is a notable correlation between vector transmission cycles and the habitats of insect vectors of the parasite. However, the scale at which these cycles operate remains uncertain. While individual triatomine ecotopes such as palms provide conditions for isolated transmission cycles, recent studies examining triatomine blood sources in various habitats suggest a more intricate network of transmission cycles, linking wild ecotopes with human dwellings. This study aims to provide further evidence on the complexity of the scale of Trypanosoma cruzi transmission cycles, by exploring the different blood sources among developmental stages of infected triatomines in different habitats. We evaluated infection rates, parasite loads, feeding sources, and the distribution of Rhodnius prolixus insects in Attalea butyracea palms across three distinct habitats in Casanare, Colombia: peridomestics, pastures, and woodlands. Our results show that there is no clear independence in transmission cycles in each environment. Analyses of feeding sources suggest the movement of insects and mammals (primarily bats and didelphids) among habitats. A significant association was found between habitat and instar stages in collected R. prolixus. The N1 stage was correlated with pasture and woodland, while the N4 stage was related to pasture. Additionally, adult insects exhibited higher T. cruzi loads than N1, N2, and N3. We observed higher T. cruzi loads in insects captured in dwelling and pasture habitats, compared with those captured in woodland areas. Effective Chagas disease control strategies must consider the complexity of transmission cycles and the interplay between domestic and sylvatic populations of mammals and vectors.
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