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![The three described species of the Triatoma dimidiata species complex. a Triatoma huehuetenanguensis, b Triatoma mopan, and c Triatoma dimidiata. All species shown to scale (10 mm). Photos by Silvia Justi and Raquel Lima-Cordón, and reproduced with permission from the authors (Lima-Cordón RA et al. [7], Figure 7, https://doi.org/10. 3897/zookeys.820.27258.figure7)](profile/Concepcion-Zuniga/publication/332479639/figure/fig1/AS:750567441850371@1555960631945/The-three-described-species-of-the-Triatoma-dimidiata-species-complex-a-Triatoma.jpg)
The three described species of the Triatoma dimidiata species complex. a Triatoma huehuetenanguensis, b Triatoma mopan, and c Triatoma dimidiata. All species shown to scale (10 mm). Photos by Silvia Justi and Raquel Lima-Cordón, and reproduced with permission from the authors (Lima-Cordón RA et al. [7], Figure 7, https://doi.org/10. 3897/zookeys.820.27258.figure7)
Source publication
![T. cruzi infection prevalence by country in Central America [6]. Map...](profile/Concepcion-Zuniga/publication/332479639/figure/fig2/AS:963438541017110@1606713056422/T-cruzi-infection-prevalence-by-country-in-Central-America-6-Map-created-using_Q320.jpg)
Purpose of Review
Chagas disease is endemic to all seven Central American countries, where 12% of the population lives in areas where the disease is a risk. While neglect is a pervasive characteristic of Chagas disease in general, it tends to be especially overlooked in Central America, with more studies and resources devoted to the disease in Sout...
Context in source publication
Context 1
... has fueled debate about the status of T. dimidiata as a single or multiple species (or subspecies), and several hypotheses of the true systematics of T. dimidiata have been proposed [47-50, 51•]. Recently, a genomic analysis revealed strong evidence that T. dimidiata is indeed a species complex comprised of three distinct species ( [52]; Fig. 1). The three species are T. dimidiata and two new species, which have recently been formally described as Triatoma mopan [5] and Triatoma huehuetenanguensis ( [7]; formerly T. sp. aff. • New cave-dwelling species, T. mopan, described in [5] • T. dimidiata collected in the Orange Walk and Corozal districts [6] • Monitor the movements of ...
Similar publications
The protozoan Trypanosoma cruzi has the ability to spontaneously secrete extracellular vesicles (EVs). In this paper, T. cruzi EVs derived from epimastigote forms were evaluated during interaction with triatomine bugs Rhodnius prolixus and Triatoma infestans. T. cruzi EVs were purified and artificially offered to the insects prior to infection with...
Citations
... Consequently, domestic parasite transmission mediated by Triatoma infestans was halted across a large endemic region covering Brazil, Chile, Uruguay, Paraguay and sections of Argentina and Bolivia [6]. Rhodnius prolixus, a major vector of Chagas disease, was apparently eliminated from Central America, and control of Triatoma dimidiata, also a major vector, progressed substantially [7,8]. For many triatomine species with extensive sylvatic foci and frequent infection with T. cruzi, such as Panstrongylus megistus and members of the Triatoma brasiliensis complex, the risk of vector-borne transmission to humans may not be negligible and requires an in-depth appraisal. ...
Background:
The Gran Chaco region is a major hotspot of Chagas disease. We implemented a 9-year program aimed at suppressing house infestation with Triatoma infestans and stopping vector-borne transmission to creole and indigenous (Qom) residents across Pampa del Indio municipality (Argentine Chaco). The aim of the present study was to assess the intervention effects on parasite-based transmission indices and the spatial distribution of the parasite, and test whether house-level variations in triatomine infection with Trypanosoma cruzi declined postintervention and were influenced by household ethnicity, persistent infestation linked to pyrethroid resistance and other determinants of bug infection.
Methods:
This longitudinal study assessed house infestation and bug infection with T. cruzi before and after spraying houses with pyrethroids and implemented systematic surveillance-and-response measures across four operational areas over the period 2007-2016. Live triatomines were individually examined for infection by optical microscopy or kinetoplast DNA (kDNA)-PCR and declared to be infected with T. cruzi when assessed positive by either method.
Results:
The prevalence of infection with T. cruzi was 19.4% among 6397 T. infestans examined. Infection ranged widely among the study areas (12.5-26.0%), household ethnicity (15.3-26.9%), bug ecotopes (1.8-27.2%) and developmental stages (5.9-27.6%), and decreased from 24.1% (baseline) to 0.9% (endpoint). Using random-intercept multiple logistic regression, the relative odds of bug infection strongly decreased as the intervention period progressed, and increased with baseline domestic infestation and bug stage and in Qom households. The abundance of infected bugs and the proportion of houses with ≥ 1 infected bug remained depressed postintervention and were more informative of area-wide risk status than the prevalence of bug infection. Global spatial analysis revealed sharp changes in the aggregation of bug infection after the attack phase. Baseline domestic infestation and baseline bug infection strongly predicted the future occurrence of bug infection, as did persistent domestic infestation in the area with multiple pyrethroid-resistant foci. Only 19% of houses had a baseline domestic infestation and 56% had ever had ≥ 1 infected bug.
Conclusions:
Persistent bug infection postintervention was closely associated with persistent foci generated by pyrethroid resistance. Postintervention parasite-based indices closely agreed with human serosurveys at the study endpoint, suggesting transmission blockage. The program identified households and population subgroups for targeted interventions and opened new opportunities for risk prioritization and sustainable vector control and disease prevention.
... Despite great strides toward vector control with the removal of Rhodnius prolixus from El Salvador in 2009 [16], vector transmission continues to occur and efforts to reduce human-vector contact in parts of the region have proven difficult. Recent evidence indicates that Triatoma dimidiata, the current primary vector causing Chagas disease in Central America, is particularly capable of re-infesting homes shortly after insecticides have been applied, and that control strategies with indoor residual insecticide are not effective in the long term [17]. Since 2016, a high pediatric Chagas disease case burden has occurred in the western department of Sonsonate [18]. ...
Congenital Chagas disease is a growing concern, prioritized by the World Health Organization for public health action. El Salvador is home to some of the highest Chagas disease (Trypanosoma cruzi infection) burdens in the Americas, yet pregnancy screening remains neglected. This pilot investigation performed a maternal T. cruzi surveillance study in Western El Salvador among women presenting for labor and delivery. From 198 consented and enrolled pregnant women, 6% were T. cruzi positive by serology or molecular diagnosis. Half of the infants born to T. cruzi-positive women were admitted to the NICU for neonatal complications. Geospatial statistical clustering of cases was noted in the municipality of Jujutla. Older women and those knowing an infected relative or close friend were significantly more likely to test positive for T. cruzi infection at the time of parturition. In closing, maternal T. cruzi infections were significantly higher than national HIV or syphilis maternal rates, creating an urgent need to add T. cruzi to mandatory pregnancy screening programs.
... Increased risk for vertical transmission has been linked to maternal poverty, malnutrition, and the presence of maternal comorbidities due to linkages with maternal immunomodulation [50]. In Guatemala, national T. cruzi prevalence is approximately 1.23% [55,57]. However, studies conducted between 2014 and 2015 in Jutiapa and Jalapa departments found between 3.3 and 10.8% T. cruzi prevalence among women of childbearing age [58,59]. ...
... Statistically significant associations between seropositive and age were observed [59]. A 2016 study in Jutiapa department found 3.8% seroprevalence among pregnant women [57]. A recent professional degree study in Chiquimula department found 27.6% seropositivity among women of childbearing age (N = 37/134), highlighting the variability and clustering of these infections in high-risk areas [60]. ...
... A recent professional degree study in Chiquimula department found 27.6% seropositivity among women of childbearing age (N = 37/134), highlighting the variability and clustering of these infections in high-risk areas [60]. In Honduras, the prevalence of Chagas among all age groups is 0.92% [57]. Among women of childbearing age, the Honduran Ministry of Health reported 1% seropositivity within the years 2015 and 2017 [57]. ...
TORCH pathogens are a group of globally prevalent infectious agents that may cross the placental barrier, causing severe negative sequalae in neonates, including fetal death and lifelong morbidity. TORCH infections are classically defined by Toxoplasma gondii, other infectious causes of concern (e.g., syphilis, Zika virus, malaria, human immunodeficiency virus), rubella virus, cytomegalovirus, and herpes simplex viruses. Neonatal disorders and congenital birth defects are the leading causes of neonatal mortality in Central America’s Northern Triangle, yet little is known about TORCH congenital syndrome in this region. This review synthesizes the little that is known regarding the most salient TORCH infections among pregnant women and neonates in Central America’s Northern Triangle and highlights gaps in the literature that warrant further research. Due to the limited publicly available information, this review includes both peer-reviewed published literature and university professional degree theses. Further large-scale studies should be conducted to clarify the public health impact these infections in this world region.
... As we developed the Ecohealth program we became aware that the approach aligns with SDG goals, and by presenting it in this framework, it becomes clear that it is an approach that can be broadly successful, not only for tackling a single disease, but to create the future we want (Figure 1). Of the 17 SDGs, we describe how the Ecohealth program addressed good health and well-being (house improvements that made houses refractory to Chagas vectors), explicitly included establishing partnerships and strengthening institutions (with Ministries of Health, NGOs, local government, etc.), building sustainable communities (use of local materials and forest restoration), and reducing inequalities (improving the highest risk houses, education, and attention to gender issues) while providing economic growth and better nutrition (domestic animal management, planting fruit trees) ( Goals 3,17,16,11,13,15,10,4,5,1,8,2,12). An important component of the Chagas Ecohealth approach is that all aspects of the control effort included decision making by members of the communities where Chagas disease is endemic. ...
... In Central America, the highest prevalence of T. cruzi infection is in Guatemala, El Salvador and Honduras (13). Data is scarce and test kits, based on South American parasite strains, are known to miss many infections (10,14), so the most recently published human T. cruzi-positive percentage (0.9 -1.3%) (15) likely underestimates the true infection prevalence. ...
... Data is scarce and test kits, based on South American parasite strains, are known to miss many infections (10,14), so the most recently published human T. cruzi-positive percentage (0.9 -1.3%) (15) likely underestimates the true infection prevalence. Estimates suggest that 12% of the Central American population lives in conditions placing them at risk of Chagas, so it remains a serious public health issue (13). ...
Despite successes in reducing transmission, Chagas disease (American trypanosomiasis) remains the greatest economic burden of any parasitic disease in Latin America afflicting mostly the poor and further contributing to poverty. We review a long-term (2001-2022), integrated Ecohealth approach that addresses sustainable development goals to reduce risk of Chagas transmission by the main native vector in Central America, Triatoma dimidiata, s.l. The basis of the Ecohealth intervention was the identification of the risk factors for house infestation, an understanding of and collaboration with local communities, and genetic and proteomic studies that revealed the epidemiology and mechanisms of the rapid reinfestation seen following insecticide application. We review the development of this approach from a pilot project in two Guatemalan villages, to an expanded initiative across three countries with vastly different ecology, cultures, and municipal organization, and finally development of a multi-institutional, large-scale project to develop a strategy to tackle the remaining hot spots in Central America. This integrated Ecohealth approach resulted in reduced risk of transmission as measured by a sustained decrease in house infestation without further use of insecticides, a reduction in vectors with human blood meals and the Chagas parasite, as well as other health and economic benefits. We discuss lessons learned and how this approach could be applied to other vector-borne diseases.
... Triatoma infestans, with the exception of Bolivia, Rhodnius prolixus in Central America) and control (e.g. Triatoma dimidiata in Central America and Triatoma brasiliensis in Brazil) [3][4][5][6][7][8][9]. The large-scale implementation of control interventions paved the way to nationwide successes in 11 of 20 endemic countries and within defined sections of other countries [5]. ...
... The large-scale implementation of control interventions paved the way to nationwide successes in 11 of 20 endemic countries and within defined sections of other countries [5]. The degree of progress of the regional programs has been widely reviewed [6][7][8][9]. One unforeseen obstacle to success in regional elimination efforts was the emergence of pyrethroid resistance in T. infestans populations on the Argentina-Bolivia border by the late 1990s and across large sections of Bolivia [10][11][12]. ...
Background
Triatomine elimination efforts and the interruption of domestic transmission of Trypanosoma cruzi are hampered by pyrethroid resistance. Fluralaner, a long-lasting ectoparasiticide administered to dogs, substantially reduced site infestation and abundance of pyrethroid-resistant Triatoma infestans Klug (Heteroptera: Reduviidae) in an ongoing 10-month trial in Castelli (Chaco Province, Argentina). We assessed the effects of fluralaner on vector infection with T. cruzi and blood meal sources stratified by ecotope and quantified its medium-term effects on site infestation and triatomine abundance.
Methods
We conducted a placebo-controlled, before-and-after efficacy trial of fluralaner in 28 infested sites over a 22-month period. All dogs received either an oral dose of fluralaner (treated group) or placebo (control group) at 0 month post-treatment [MPT]. Placebo-treated dogs were rescue-treated with fluralaner at 1 MPT, as were all eligible dogs at 7 MPT. Site-level infestation and abundance were periodically assessed by timed manual searches with a dislodging aerosol. Vector infection was mainly determined by kDNA-PCR and blood meal sources were determined by enzyme-linked immunosorbent assay.
Results
In fluralaner-treated households, site infestation dropped from 100% at 0 MPT to 18–19% over the period 6–22 MPT while mean abundance plummeted from 5.5 to 0.6 triatomines per unit effort. In control households, infestation dropped similarly post-treatment. The overall prevalence of T. cruzi infection steadily decreased from 13.8% at 0–1 MPT (baseline) to 6.4% and subsequently 2.3% thereafter, while in domiciles, kitchens and storerooms it dropped from 17.4% to 4.7% and subsequently 3.3% thereafter. Most infected triatomines occurred in domiciles and had fed on humans. Infected-bug abundance plummeted after fluralaner treatment and remained marginal or nil thereafter. The human blood index of triatomines collected in domiciles, kitchens and storerooms highly significantly fell from 42.9% at baseline to 5.3–9.1% over the period 6–10 MPT, increasing to 36.8% at 22 MPT. Dog blood meals occurred before fluralaner administration only. The cat blood index increased from 9.9% at baseline to 57.9–72.7% over the period 6–10 MPT and dropped to 5.3% at 22 MPT, whereas chicken blood meals rose from 39.6% to 63.2–88.6%.
Conclusion
Fluralaner severely impacted infestation- and transmission-related indices over nearly 2 years, causing evident effects at 1 MPT, and deserves larger efficacy trials.
Graphical Abstract
... Chagas disease, caused by Trypanosoma cruzi, is a major neglected health problem in Central America, leading to significant economic losses due to reduced productivity from early-age disability and mortality [1]. More than 10% of people in this region live in Chagas disease risk areas, and nearly 400,000 people are estimated to be infected with this protozoan parasite [2][3][4]. ...
... It has a tropical climate, with relatively high peratures throughout the year, ranging from 26 °C to 32 °C, and two marked seasons Season: January-May; Rainy Season: May-December. The Pan American Health Or zation (PAHO) considers Panama an area endemic for Chagas disease where the syl behavior of the main vectors recognized in the country (R. pallescens, Triatoma dim and Panstrongylus geniculatus) complicates current approaches to control vectorial t mission [4,33]. These triatomine species are widespread and are responsible for main ing sylvatic transmission cycles that vary in intensity across different rural and subu regions of Panama. ...
... It has a tropical climate, with relatively high temperatures throughout the year, ranging from 26 • C to 32 • C, and two marked seasons: Dry Season: January-May; Rainy Season: May-December. The Pan American Health Organization (PAHO) considers Panama an area endemic for Chagas disease where the sylvatic behavior of the main vectors recognized in the country (R. pallescens, Triatoma dimidiata and Panstrongylus geniculatus) complicates current approaches to control vectorial transmission [4,33]. These triatomine species are widespread and are responsible for maintaining sylvatic transmission cycles that vary in intensity across different rural and suburban regions of Panama. ...
The objective of this study was to provide information on Trypanosoma cruzi genetic diversity among isolates obtained from different biological sources circulating in endemic areas of Panama. Initial discrete typing units (DTUs) assignment was performed evaluating three single locus molecular markers (mini-exon, heat shock protein 60 and glucose-6-phosphate isomerase genes). Further diversity within TcI lineages was explored using a multi-locus sequence typing approach with six maxicircle genes. Haplotype network analysis and evolutionary divergency estimations were conducted to investigate the genetic relatedness between Panamanian TcI isolates and isolates from different endemic regions in the Americas. Our molecular approach validated that TcI is the predominant DTU circulating in Panama across different hosts and vector species, but also confirmed the presence of TcIII and TcVI circulating in the country. The phylogenetic tree topography for most Panamanian TcI isolates displayed a high level of genetic homogeneity between them. The haplotype network analysis inferred a higher genetic diversity within Panamanian TcI isolates, displaying eight different haplotypes circulating in endemic regions of the country, and revealed geographical structuring among TcI from different endemic regions in the Americas. This study adds novelty on the genetic diversity of T. cruzi circulating in Panama and complements regional phylogeographic studies regarding intra-TcI variations.
... Chagas disease is considered the fourth highest burden of infectious diseases in Central America, behind HIV/AIDS, acute respiratory infections, and acute diarrheal diseases [1]. Trypanosoma cruzi has been identified as the causal agent of Chagas disease. ...
... El Salvador has a population of 6.5 million and approximately 39% of the population is at risk of contracting this disease [3]. The latest official data on Chagas disease, from the Health's Ministry of El Salvador, conclude that between 2014 and 2017, 771 chronic cases and 53 acute cases were reported and the prevalence of T. cruzi in blood banks is among the highest in the Americas, fluctuating between 1.5 and 3.9% in 2008-2016 [1]. ...
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi , and in Central America, it is considered one of the four most infectious diseases. This study aimed to screen the anti-trypanosomal activity of plant species from Salvadoran flora. Plants were selected through literature search for plants ethnobotanically used for antiparasitic and Chagas disease symptomatology, and reported in Museo de Historia Natural de El Salvador (MUHNES) database. T. cruzi was incubated for 72 h with 2 different concentrations of methanolic extracts of 38 species, among which four species, Piper jacquemontianum , Piper lacunosum , Trichilia havanensis , and Peperomia pseudopereskiifolia , showed the activity (≤ 52.0% viability) at 100 µg/mL. Separation of the methanolic extract of aerial parts from Piper jacquemontianum afforded a new flavanone ( 4 ) and four known compounds, 2,2-dimethyl-6-carboxymethoxychroman-4-one ( 1 ), 2,2-dimethyl-6-carboxychroman-4-one ( 2 ), cardamomin ( 3 ), and pinocembrin ( 5 ), among which cardamomin exhibited the highest anti-trypanosomal activity (IC 50 = 66 µM). Detailed analyses of the spectral data revealed that the new compound 4 , named as jaqueflavanone A, was a derivative of pinocembrin having a prenylated benzoate moiety at the 8-position of the A ring.
Graphic abstract
... In Central America, the prevalence of Chagas disease has declined significantly since the 1980s, thanks in part to the near-elimination of the invasive vector Rhodnius prolixus. However, the species-complex Triatoma dimidiata still poses a significant health risk to millions of people in many areas [11]. Unlike the invasive R. prolixus, T. dimidiata is endemic to the continent and infests peridomestic and sylvatic environments [12]. ...
... The limitations of insecticide for control of T. dimidiata in Guatemala have led to the gradual adoption of additional measures, mostly in the departments of Jutiapa and Chiquimula in southeastern Guatemala, which represent the majority of the country's cases reported to the Ministry of Health [11,26]. A promising multidisciplinary approach, often referred to as the EcoHealth approach, applies cost-effective, locally-tailored house and peridomestic improvements by collaborating with villagers and health personnel, in conjunction with initial insecticide application [21]. ...
Widespread application of insecticide remains the primary form of control for Chagas disease in Central America, despite only temporarily reducing domestic levels of the endemic vector Triatoma dimidiata and having little long-term impact. Recently, an approach emphasizing community feedback and housing improvements has been shown to yield lasting results. However, the additional resources and personnel required by such an intervention likely hinders its widespread adoption. One solution to this problem would be to target only a subset of houses in a community while still eliminating enough infestations to interrupt disease transfer. Here we develop a sequential sampling framework that adapts to information specific to a community as more houses are visited, thereby allowing us to efficiently find homes with domiciliary vectors while minimizing sampling bias. The method fits Bayesian geostatistical models to make spatially informed predictions, while gradually transitioning from prioritizing houses based on prediction uncertainty to targeting houses with a high risk of infestation. A key feature of the method is the use of a single exploration parameter, $\alpha$, to control the rate of transition between these two design targets. In a simulation study using empirical data from five villages in southeastern Guatemala, we test our method using a range of values for $\alpha$, and find it can consistently select fewer homes than random sampling, while still bringing the village infestation rate below a given threshold. We further find that when additional socioeconomic information is available, much larger savings are possible, but that meeting the target infestation rate is less consistent, particularly among the less exploratory strategies. Our results suggest new options for implementing long-term T. dimidiata control.
... Following the initial successes in the Southern Cone (Silveira et al. 2002), the longterm labor of the initiatives documented nationwide success in 11 of the 20 recognized endemic countries and within defined sections of other countries and more lately addressed the challenges of congenital transmission and etiologic treatment (Pan American Health Organization 2018). Most of its underpinnings and outcomes have been widely reviewed (Silveira et al. 2002;Dias and Schofield 2004;Yamagata andNakagawa 2006, Gorla andHashimoto 2017;Peterson et al. 2019). ...
Most of the human infections with Trypanosoma cruzi are caused by triatomine species adapted to thrive in domestic habitats and blood-feed on humans. Residual house spraying with insecticides applied by public health personnel remains the mainstay of triatomine control, with pyrethroids being in use for nearly 40 years. Here, we review the vector control methods applied to triatomines of public health relevance. We examine the effectiveness and epidemiological impact of residual house spraying and housing improvement, and its main limitations, and focus on the reinfestation process and the putative sources of reinfestants. High levels of pyrethroid resistance associated with triatomine control failures appeared in the late 1990s and so far have remained restricted to northern Argentina and Bolivia. Peridomestic foci and effective vector surveillance at low bug densities remain the Achilles’ heel of triatomine control programs. Other insecticide delivery systems of limited use include disposable fumigant canisters and insecticidal paints. Housing improvements and other multisectoral measures directed to prevent house colonization have not been exploited to its full potential and may play an important role for sustainable vector control across diseases. Integrating vector and disease management efforts may be the key to long-term program sustainability in the affected areas.
... (2,12,13,14) Because JICA-sponsored projects did not include infection diagnosis and treatment, IPCA countries sought alternative support sources; an example of international cooperation towards that end is the "Alliances project" in Guatemala. (15) The interruption of CD transmission by non-native R. prolixus in Mexico and Central America is, together with universal, mandatory blood-donor screening, the most important IPCAM achievement. (2) By 2011, the PAHO-WHO had certified the elimination of R. prolixus from Mexico, Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica. ...
Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi. Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives' aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi, however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.
