Quality assurance of serologic testing for Chagas disease in a primary care setting of rural Paraguay.

The diagnosis of Chagas disease mostly relies on the use of multiple serologic tests that are often unavailable in many of the remote settings where the disease is highly prevalent. In the Teniente Irala Fernández Municipality, in central Paraguay, efforts have been made to increase the diagnostic capabilities of specific rural health centres, but no quality assurance of the results produced has been performed. We comparatively analysed the results obtained with 300 samples tested using a commercial rapid diagnostic test (RDT) and enzyme linked immunosorbent assays (ELISA) at the laboratory of the Teniente Irala Fernández Health Center (CSTIF) with those generated upon repeating the tests at an independent well-equipped research laboratory (CEDIC). A subgroup of 52 samples were further tested at Paraguay's Central Public Health Laboratory (LCSP) by means of a different technique to evaluate the diagnostic performance of the tests carried out at CSTIF. We observed an excellent agreement between the ELISA results obtained at CSTIF and CEDIC (kappa coefficients between 0.85 and 0.93 for every kit evaluated), and an overall good performance of the tests carried out at CSTIF. However, the sensitivity of one kit was lower at CSTIF (81.3 %) than at CEDIC (100 %). The individual use of an RDT to detect the infection at CSTIF showed a similar sensitivity to that obtained combining it to an ELISA test (92.3% vs 88.5, p = 1). Nonetheless, the generalizability of this result is yet limited and will require of further studies.

Unraveling the Missing Pieces: Exploring the Gaps in Understanding Chagas Cardiomyopathy.

Chagas cardiomyopathy affects a considerable number of patients infected with the protozoan Trypanosoma cruzi (T. cruzi) and remains one of the most neglected tropical diseases despite being a significant contributor to morbidity and mortality in both endemic regions of Latin America and non-endemic countries like the United States. Since its discovery almost a century ago, knowledge gaps still exist in the mechanisms involved in the pathogenesis of Chagas cardiomyopathy, and numerous challenges exist in its diagnosis and treatment. This article reviews the main pathogenetic mechanisms involved in the progression of Chagas cardiomyopathy, which has been proposed as a result of years of research. It also emphasizes the challenges involved in the diagnosis of the asymptomatic indeterminate phase and has focused on several diagnostic techniques, including echocardiography, electrocardiogram (ECG), magnetic resonance imaging (MRI), and nuclear imaging in diagnosing symptomatic Chagas cardiomyopathy. In this article, we have also provided a brief overview of the current treatment of Chagas cardiomyopathy, which is not etiology-specific but instead derived from the knowledge acquired from the treatment of other cardiomyopathies.

Prevalence of Chagas disease among Latin American immigrants in non-endemic countries: an updated systematic review and meta-analysis.

Background: Chagas disease (CD), endemic in 21 Latin American countries, has gradually spread beyond its traditional borders due to migratory movements and emerging as a global health concern. We conducted a systematic review and meta-analysis of available data to establish updated prevalence estimates of CD in Latin American migrants residing in non-endemic countries. Methods: A systematic search was conducted in MEDLINE/PubMed, Embase, Cochrane Library, Scopus, Web of Science, and LILACS via Virtual Health Library (Biblioteca Virtual em Saúde - BVS), including references published until November 1st, 2023. Pooled prevalence estimates and 95% confidence intervals (CI) were calculated using random effect models. Heterogeneity was assessed by the chi-square test and the I2 statistic. Subgroup analyses were performed to explore potential sources of heterogeneity among studies. The study was registered in the PROSPERO database (CRD42022354237). Findings: From a total of 1474 articles screened, 51 studies were included. Studies were conducted in eight non-endemic countries (most in Spain), between 2006 and 2023, and involving 82,369 screened individuals. The estimated pooled prevalence of CD in Latin American migrants living in non-endemic countries was 3.5% (95% CI: 2.5-4.7; I2: 97.7%), considering studies in which screening was indicated simply because the person was Latin American. Per subgroups, the pooled CD prevalence was 11.0% (95% CI: 7.7-15.5) in non-targeted screening (unselected population in reference centers) (27 studies); in blood donors (4 studies), the pooled prevalence was 0.8% (95% CI: 0.2-3.4); among people living with HIV Latin American immigrants (4 studies) 2.4% (95% CI: 1.4-4.3) and for Latin American pregnant and postpartum women (14 studies) 3.7% (95 CI: 2.4-5.6). The pooled proportion of congenital transmission was 4.4% (95% CI: 3.3-5.8). Regarding the participants' country of origin, 7964 were from Bolivia, of which 1715 (21,5%) were diagnosed with CD, and 21,304 were from other Latin American countries of which 154 (0,72%) were affected. Interpretation: CD poses a significant burden of disease in Latin American immigrants in non-endemic countries, suggesting that CD is no longer a problem limited to the American continent and must be considered as a global health challenge. Funding: This study was funded by the World Heart Federation, through a research collaboration with Novartis Pharma AG.

Causality and Severity of Adverse Reactions and Biochemical Changes to Benznidazole Treatment in Patients with Chronic Chagas Disease. / Causalidade e Gravidade das Reações Adversas e Alterações Laboratoriais ao Tratamento com Benznidazol em Pacientes com Doença de Chagas Crônica.

BACKGROUND: Chagas disease (CD) is a serious public health problem in Latin America. Benznidazole (BNZ) is used for the treatment of CD and, despite its wide use, little information is available about its toxicity and mechanisms of adverse drug reactions (ADR). OBJECTIVES: To identify and classify clinical and laboratory adverse reactions caused by BNZ in terms of causality and severity. METHODS: Prospective cohort study from January 2018 to December 2021. Treatment follow-up included visits and biochemical tests (complete blood count, liver and kidney function tests) before, during and after treatment. ADR were classified according to causality and severity. In the statistical analysis, the significance level was set at p<0.05. RESULTS: Forty patients with chronic CD were included. A high prevalence of ADR was observed 161 ADR in 30 patients [90%]; of these, 104 (64.6%) were classified as possible and 57 (35.4%) as probable. The ADR were classified as moderate and mild. Of the 40 patients, nine (22.5%) discontinued treatment. ADR associated with treatment discontinuation and interventions were those that affected the dermatological system, central and peripheral nervous system and sense organs such as ageusia. Mild hematological and biochemical changes such as lymphopenia were observed after 30 days of treatment. CONCLUSION: Many patients were able to complete the treatment even with ADR, which can be attributed to the successful follow-up strategy with symptomatic treatment and counseling, leading to patient's awareness of symptoms and treatment adherence.

FUNDAMENTO: A Doença de Chagas (DC) representa um grave problema de saúde pública na América Latina. O Benznidazol (BNZ) é utilizado para o tratamento DC e, apesar do seu amplo uso, poucas informações estão disponíveis sobre sua toxicidade e mecanismos das Reações Adversas ao Medicamento (RAM). OBJETIVOS: Identificar e classificar as reações adversas clínicas e laboratoriais ocasionadas pelo uso do BNZ quanto à sua causalidade e gravidade. MÉTODOS: Estudo de coorte prospectivo realizado no período de janeiro de 2018 a dezembro de 2021. O acompanhamento do tratamento incluiu consultas e análises laboratoriais antes, 30 e 60 dias após o início do tratamento. As RAM foram classificadas quanto à causalidade e gravidade. Na análise estatística o nível de significância adotado foi p<0,05. RESULTADOS: Participaram do estudo 40 pacientes com DC crônica, observou-se alta prevalência de RAM com um total de 161 em 30 (90%) pacientes. Destas, 104 (64,6%) foram classificadas como possíveis e 57 (35,4%) como prováveis. As reações foram classificadas em moderadas e leves. Dos 40 pacientes, nove (22,5%) suspenderam o tratamento. As RAM associadas à interrupção e intervenções foram as que afetaram o sistema dermatológico, sistema nervoso central e periférico ou que culminaram em ageusia. Após 30 dias de tratamento, alterações hematológicas e bioquímicas leves foram observadas como linfopenia. CONCLUSÃO: Apesar do elevado percentual de RAM, muitos pacientes foram capazes de completar o tratamento, o que se atribui ao êxito da estratégia de acompanhamento com intervenções de tratamento sintomático juntamente ao aconselhamento, levando à compreensão da sintomatologia e manutenção do tratamento.

Prevention of congenital chagas disease by trypanocide treatment in women of reproductive age: A meta-analysis of observational studies.

BACKGROUND: Maternal-foetal transmission of Chagas disease (CD) affects newborns worldwide. Although Benznidazole and Nifurtimox therapies are the standard treatments, their use during pregnancy is contra-indicated. The effectiveness of trypanocidal medications in preventing congenital Chagas Disease (cCD) in the offsprings of women diagnosed with CD was highly suggested by other studies. METHODS: We performed a systematic review and meta-analysis of studies evaluating the effectiveness of treatment for CD in women of childbearing age and reporting frequencies of cCD in their children. PubMed, Scopus, Web of Science, Cochrane Library, and LILACS databases were systematically searched. Statistical analysis was performed using Rstudio 4.2 using DerSimonian and Laird random-effects models. Heterogeneity was examined with the Cochran Q test and I2 statistics. A p-value of <0.05 was considered statistically significant. RESULTS: Six studies were included, comprising 744 children, of whom 286 (38.4%) were born from women previously treated with Benznidazole or Nifurtimox, trypanocidal agents. The primary outcome of the proportion of children who were seropositive for cCD, confirmed by serology, was signigicantly lower among women who were previously treated with no congenital transmission registered (OR 0.05; 95% Cl 0.01-0.27; p = 0.000432; I2 = 0%). In women previously treated with trypanocidal drugs, the pooled prevalence of cCD was 0.0% (95% Cl 0-0.91%; I2 = 0%), our meta-analysis confirms the excellent effectiveness of this treatment. The prevalence of adverse events in women previously treated with antitrypanocidal therapies was 14.01% (95% CI 1.87-26.14%; I2 = 80%), Benznidazole had a higher incidence of side effects than Nifurtimox (76% vs 24%). CONCLUSION: The use of trypanocidal therapy in women at reproductive age with CD is an effective strategy for the prevention of cCD, with a complete elimination of congenital transmission of Trypanosoma cruzi in treated vs untreated infected women.

RhoprCAPA-2 acts as a gonadotropin regulating reproduction in adult female, Rhodnius prolixus.

CAPA peptides play diverse roles in insects, modulating muscle contraction, regulating fluid balance, and reproduction. In Rhodnius prolixus, a hematophagous insect and a vector for human Chagas disease, three CAPA peptides are encoded by the capability gene, including RhoprCAPA-1, RhoprCAPA-2, and RhoprCAPA-PK-1. RhoprCAPA-2 is an anti-diuretic hormone in R. prolixus. Here, we explore the involvement of RhoprCAPA-2 in reproduction in adult female R. prolixus. Double-label immunohistochemistry reveals co-localization of RhoprCAPA-2-like and the glycoprotein hormone (GPA2/GPB5) subunit GPB5-like immunoreactivity in neurosecretory cells in the mesothoracic ganglionic mass and in their neurohemal sites, suggesting these peptides can be co-released to regulate physiological processes. qPCR analysis reveals changes in transcript expression levels of the RhoprCAPA receptor (CAPAR) in the fat body and reproductive tissues after feeding in adult female R. prolixus. RNA interference-mediated knockdown of CAPAR transcript decreases egg production and reduces hatching rate and survival rate in female R. prolixus. Downregulation of CAPAR decreases vitellogenin RhoprVg1 transcript expression in the fat body and deceases its receptor RhoprVgR transcript level in the ovaries; accompanied by a reduction in vitellogenin content in the fat body and hemolymph. Incubation of fat body and ovaries in vitro with RhoprCAPA-2 increases RhoprVg1 transcript expression in the fat body, vitellogenin content in the fat body culture medium, and increases RhoprVgR transcript in the ovaries. These findings implicate the CAPA signaling pathway in reproduction, with RhoprCAPA-2 acting as a gonadotropin in adult female R. prolixus.

Cyclodextrin Complexes for the Treatment of Chagas Disease: A Literature Review.

Cyclodextrins are ring-shaped sugars used as additives in medications to improve solubility, stability, and sensory characteristics. Despite being widespread, Chagas disease is neglected because of the limitations of available medications. This study aims to review the compounds used in the formation of inclusion complexes for the treatment of Chagas disease, analyzing the incorporated compounds and advancements in related studies. The databases consulted include Scielo, Scopus, ScienceDirect, PubMed, LILACS, and Embase. The keywords used were "cyclodextrin AND Chagas AND disease" and "cyclodextrin complex against Trypanosoma cruzi". Additionally, a statistical analysis of studies on Chagas disease over the last five years was conducted, highlighting the importance of research in this area. This review focused on articles that emphasize how cyclodextrins can improve the bioavailability, therapeutic action, toxicity, and solubility of medications. Initially, 380 articles were identified with the keyword "cyclodextrin AND Chagas disease"; 356 were excluded for not being directly related to the topic, using the keyword "cyclodextrin complex against Trypanosoma cruzi". Over the last five years, a total of 13,075 studies on Chagas disease treatment were found in our literature analysis. The studies also showed interest in molecules derived from natural products and vegetable oils. Research on cyclodextrins, particularly in the context of Chagas disease treatment, has advanced significantly, with studies highlighting the efficacy of molecules in cyclodextrin complexes and indicating promising advances in disease treatment.

Structure-Aided Computational Design of Triazole-Based Targeted Covalent Inhibitors of Cruzipain.

Cruzipain (CZP), the major cysteine protease present in T. cruzi, the ethiological agent of Chagas disease, has attracted particular attention as a therapeutic target for the development of targeted covalent inhibitors (TCI). The vast chemical space associated with the enormous molecular diversity feasible to explore by means of modern synthetic approaches allows the design of CZP inhibitors capable of exhibiting not only an efficient enzyme inhibition but also an adequate translation to anti-T. cruzi activity. In this work, a computer-aided design strategy was developed to combinatorially construct and screen large libraries of 1,4-disubstituted 1,2,3-triazole analogues, further identifying a selected set of candidates for advancement towards synthetic and biological activity evaluation stages. In this way, a virtual molecular library comprising more than 75 thousand diverse and synthetically feasible analogues was studied by means of molecular docking and molecular dynamic simulations in the search of potential TCI of CZP, guiding the synthetic efforts towards a subset of 48 candidates. These were synthesized by applying a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) centered synthetic scheme, resulting in moderate to good yields and leading to the identification of 12 hits selectively inhibiting CZP activity with IC50 in the low micromolar range. Furthermore, four triazole derivatives showed good anti-T. cruzi inhibition when studied at 50 µM; and Ald-6 excelled for its high antitrypanocidal activity and low cytotoxicity, exhibiting complete in vitro biological activity translation from CZP to T. cruzi. Overall, not only Ald-6 merits further advancement to preclinical in vivo studies, but these findings also shed light on a valuable chemical space where molecular diversity might be explored in the search for efficient triazole-based antichagasic agents.

Climate change and Trypanosoma cruzi transmission in North and central America.

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease in humans. Transmission of T cruzi by triatomine vectors is dependent on diverse environmental and socioeconomic factors. Climate change, which is disrupting patterns of human habitation and land use, can affect the epidemiology of Chagas disease by influencing the distribution of vector and host species. We conducted a review using triatomine distribution as a proxy for T cruzi transmission in North America (Canada, Mexico, and the USA) and central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama) and investigated the association of T cruzi transmission with climate change, identifying 12 relevant studies. Most studies (n=9) modelled the effect of the scenario of climate change on the distribution of relevant vector species and found that global warming could sometimes favour and sometimes hinder triatomine distribution. There is a need for more research in parasite biology and social sciences to further understand how climate change and socioeconomic factors can affect the epidemiology of this neglected tropical disease.

Vitamin D treatment distinctly modulates cytokine production by peripheral blood mononuclear cells among patients with chronic cardiac and indeterminate clinical forms of Chagas disease.

INTRODUCTION: Chagas disease is caused by the protozoan Trypanosoma cruzi and is clinically divided into acute and chronic phases. Chronic Chagas cardiomyopathy is the most studied manifestation of the disease. Vitamin D deficiency has been suggested as a risk factor for cardiovascular disease. No studies demonstrate the action of this hormone in the cells of patients with chronic Chagas heart disease. OBJECTIVE: To evaluate the in vitro immunomodulatory effect of vitamin D on peripheral blood mononuclear cells of patients with the different chronic clinical forms of Chagas disease. Evaluating vitamin D's in vitro effect on blood cells by producing cytokines. METHODS: Thirteen patients of the undetermined form (IND), 13 of the mild cardiac form (CARD1) and 14 of the severe cardiac form (CARD2) of Chagas disease, and 12 with idiopathic heart disease (CARDid) were included. The cells obtained from peripheral blood were treated in vitro with vitamin D (1 × 10-7 M) for 24 h and cytokines were dosed in the culture supernatant. RESULTS: Although it was not possible to demonstrate statistically significant differences between the groups studied, our data showed that the cells treated with vitamin D modify (p < .05) the production of interferon-γ (IFN-γ) (decrease in IND), tumor necrosis factor-α (TNF-α) (decreased in CARD1 and CARDid), interleukin (IL)-6 (increased in all groups), and IL-10 (decreased in CARD1, CARD2, and CARDid) when compared to untreated cells. CONCLUSION: In vitro treatment with vitamin D distinctly modulated the production of cytokines by mononuclear cells of peripheral blood among patients with chronic and indeterminate cardiac clinical forms of Chagas disease.

A Rhodnius prolixus catalytically inactive Calpain protease patterns the insect embryonic dorsal-ventral axis.

The calcium dependent Calpain proteases are modulatory enzymes with important roles in cell cycle control, development and immunity. In the fly model Drosophila melanogaster Calpain A cleaves Cactus/IkappaB and consequently modifies Toll signals during embryonic dorsal-ventral (DV) patterning. Here we explore the role of Calpains in the hemiptera Rhodnius prolixus, an intermediate germband insect where the Bone Morphogenetic Protein (BMP) instead of the Toll pathway plays a major role in DV patterning. Phylogenetic analysis of Calpains in species ranging from Isoptera to Diptera indicates an increase of Calpain sequences in the R. prolixus genome and other hemimetabolous species. One locus encoding each of the CalpC, CalpD and Calp7 families, and seven Calpain A/B loci are present in the R. prolixus genome. Several predicted R. prolixus Calpains display a unique architecture, such as loss of Calcium-binding EF-hand domains and loss of catalytic residues in the active site CysPc domain, yielding catalytically dead Calpains A/B. Knockdown for one of these inactive Calpains results in embryonic DV patterning defects, with expansion of ventral and lateral gene expression domains and consequent failure of germ band elongation. In conclusion, our results reveal that Calpains may exert a conserved function in insect DV patterning, despite the changing role of the Toll and BMP pathways in defining gene expression territories along the insect DV axis.

Dissimilar Trypanosoma cruzi genotype-specific serological profile assessed by Chagas-Flow ATE IgG1 upon benznidazole etiological treatment of chronic Chagas disease.

The present study aimed to verify the impact of etiological treatment on the genotype-specific serological diagnosis of chronic Chagas disease patients (CH), using the Chagas-Flow ATE IgG1 methodology. For this purpose, a total of 92 serum samples from CH, categorized as Not Treated (NT, n = 32) and Benznidazole-Treated (Bz-T, n = 60), were tested at Study Baseline and 5Years Follow-up. At Study Baseline, all patients have the diagnosis of Chagas disease confirmed by Chagas-Flow ATE IgG1, using the set of attributes ("antigen/serum dilution/cut-off"; "EVI/250/30%"). The genotype-specific serodiagnosis at Study Baseline demonstrated that 96% of patients (44/46) presented a serological profile compatible with TcII genotype infection. At 5Years Follow-up monitoring, NT and Bz-T presented no changes in anti-EVI IgG1 reactivity. However, significant differences were detected in the genotype-specific IgG1 reactivity for Bz-T. The most outstanding shift comprised the anti-amastigote TcVI/(AVI), anti-amastigote TcII/(AII) and anti-epimastigote TcVI/(EVI) reactivities. Regardless no changes in the genotype-specific serology of NT (TcI = 6%; TcII = 94%), distinct T. cruzi genotype-specific sero-classification was detected for Bz-T samples at 5Years Follow-up (TcII = 100%) as compared to Baseline (TcII = 97%; TcVI = 3%). The anti-trypomastigote TcI/(TI) was the attribute accountable for the change in genotype-specific sero-classification. In conclusion, our findings of dissimilar T. cruzi genotype-specific serology upon Bz-treatment re-emphasize the relevance of accomplishing the genotype-specific serodiagnosis during clinical pos-therapeutic management of chronic Chagas disease patients.

Triatomine (Hemiptera: Reduviidae) populations and Trypanosoma cruzi genotyping in peridomestic and sylvatic environments in the semiarid region of Sergipe, Northeastern, Brazil.

We assessed the diversity of triatomines, the rates of natural infection, and the discrete typing units (DTUs) of Trypanosoma cruzi isolated from them in two municipalities in the state of Sergipe, Brazil. Active searches for triatomines were conducted in the peridomicily and wild enviroments of 10 villages within the two municipalities. Triatomines were taxonomically identified and their feces were extracted using the abdominal compression method. Parasite detection was performed using optical microscopy. For Trypanosoma cruzi genotyping via PCR-FFLB, 151 samples of the subspecies Triatoma brasiliensis macromelasoma and Triatoma brasiliensis were isolated from both municipalities. In total, 505 triatomines were collected, with Triatoma brasiliensis macromelasoma being the most frequent species (58.81 %). Triatoma b. brasiliensis was the only species in both peridomestic and wild environments. Regarding the other species, T. pseudomaculata was found only in the peridomestic environment; and T. b. macromelasoma and Psammolestes tertius were found in the wild environment. Three Discrete Typing Units were identified: TcI (87.51 %) detected in T. b. brasiliensis and T. b. macromelasoma, TcI+TcIII (10.41 %) in T. b. macromelasoma, and TcI+Trypanosoma rangeli (2.08 %) in T. b. macromelasoma. It is concluded that T. b. macromelasoma is the species collected most frequently in the studied region and the one that presents the highest rates of natural infection, highlighting its epidemiological importance for the vectorial transmission of Chagas disease in Sergipe.

Prevalence analysis of Chagas disease by age group in an endemic region of Brazil: possible scenario of active vectorial transmission.

Objectives: Chagas disease (CD) is an infectious disease that predominantly affects poor and vulnerable populations. The last estimate conducted by the World Health Organization in Latin America regarding the prevalence of CD occurred more than 10 years ago. However, there is a scarcity of data assessing the magnitude of CD in populations residing in considered high-risk regions. Therefore, this study aimed to assess the seroprevalence of CD in an endemic region in Northern Minas Gerais through serologic screening. Methods: This is a prevalence study conducted in the municipalities of Catuti, Mato Verde, Mirabela, Montes Azul, and São Francisco, Minas Gerais, Brazil. Data collection occurred between December 2021 and December 2022, involving a questionnaire with closed-ended questions. The variables analyzed included serologic test results, stratified age groups, health indicators, and housing conditions. Results: Of the 2978 participants, 272 individuals (9.1%) tested positive for CD serology. In the age group of 4 to 14 years, 15 to 49 years, and 50 years or older, the prevalence of positive serology was 0.8% (95% confidence interval [CI] 0.16-1.43), 5.5% (95% CI 4.20-6.83), and 18.8% (95% CI 16.48-21.11), respectively. Among the participating municipalities, Mato Verde had the highest prevalence of positive serology for CD (17%). For participants aged 4 to 14 years with positive serology for CD, first-degree relatives were invited to undergo serologic testing. It was possible to collect samples from relatives of all participants in this age group. However, none of the relatives tested positive. Conclusion: This study identified a 9.1% prevalence of individuals affected by CD who were unaware of their condition. In addition, having infected children in the 4 to 14 age group with mothers with negative serology would rule out congenital transmission of the disease.

Phlebotomine sand fly (Diptera: Psychodidae) fauna, blood meal source, and detection of Leishmania (Kinetoplastida: Trypanosomatidae) DNA in the Gurupi Biological Reserve, Eastern Amazon, Brazil.

This study was conducted in the Gurupi Biological Reserve (REBIO-Gurupi), the largest area of Amazon rainforest in Maranhão State, Brazil. The objectives were to survey the sand fly (Diptera: Psychodidae) fauna of REBIO-Gurupi, identify blood meal sources, and investigate the presence of Leishmania (Ross, 1903) (Kinetoplastida: Trypanosomatidae) DNA. Individuals were collected using Centers for Disease Control (CDC) light traps and black and white Shannon traps in May and Jun 2022 and Jan 2023. DNA was extracted from female sand flies and subjected to amplification and sequencing of cytochrome b molecular marker (CYTB) for identification of blood meal sources and the first internal transcribed spacer (ITS-1) of ribosomal DNA for Leishmania detection. A total of 514 sand flies individuals were sampled, of which 93 were identified at the genus or series level (9 taxa) and 421 were identified at the species level (24 taxa). Psychodopygus davisi (Root, 1934) (41.1%), Nyssomyia antunesi (Coutinho, 1939) (10.3%), and Psychodopygus (Mangabeira, 1941) Chagasi Series Barretto, 1962 (9.7%) were the most frequently collected. Human (Homo sapiens, Primates, Hominidae) and tapir (Tapirus terrestris, Perissodactyla, Tapiridae) DNA was detected in 10 female sand flies. Leishmania (Leishmania) infantum Cunha and Chagas, 1937 DNA was detected in 2 specimens of Ps. davisi. Given the presence of vectors of Leishmania in REBIO-Gurupi, it is imperative to conduct more comprehensive studies on the interactions among sand flies, Leishmania, and pathogen reservoirs in the area.

Acute Chagas disease outbreaks in Colombia in 2019.

This study seeks to address the critical knowledge gap surrounding the acute phase of Chagas disease in Colombia, with a specific focus on cases reported in 2019. The acute phase of Chagas disease is a pivotal period for intervention, yet it remains poorly understood, particularly in regions where oral transmission is presumed to be a significant factor. By analyzing these recent cases, our research aims to provide a deeper understanding of the dynamics of Chagas disease during its acute phase in Colombia in 2019. This understanding is essential not only for improving disease management and treatment strategies but also for enhancing public health responses to this neglected tropical disease. In particular, our study highlights the importance of identifying and addressing the unique challenges posed by oral transmission routes, which have been increasingly recognized within Colombia's Chagas disease landscape.

Irrigation, migration and infestation: a case study of Chagas disease vectors and bed bugs in El Pedregal, Peru.

BACKGROUND: The city of El Pedregal grew out of a desert, following an agricultural irrigation project in southern Peru. OBJECTIVES: To describe infestation patterns by triatomines and bed bugs and their relationship to migration and urbanization. METHODS: We conducted door-to-door entomological surveys for triatomines and bed bugs. We assessed spatial clustering of infestations and compared the year of construction of infested to un-infested households. To gain a better understanding of the context surrounding triatomine infestations, we conducted in-depth interviews with residents to explore their migration histories, including previous experiences with infestation. FINDINGS: We inspected 5,164 households for Triatoma infestans (known locally as the Chirimacha); 21 (0.41%) were infested. These were extremely spatially clustered (Ripley's K p-value < 0.001 at various spatial scales). Infested houses were older than controls (Wilcoxon rank-sum: W = 33; p = 0.02). We conducted bed bug specific inspections in 34 households; 23 of these were infested. These were spatially dispersed across El Pedregal, and no difference was observed in construction age between bed bug infested houses and control houses (W = 6.5, p = 0.07). MAIN CONCLUSIONS: The establishment of agribusiness companies in a desert area demanded a permanent work force, leading to the emergence of a new city. Migrant farmers, seeking work opportunities or escaping from adverse climatic events, arrived with few resources, and constructed their houses with precarious materials. T. infestans, a Chagas disease vector, was introduced to the city and colonized houses, but its dispersal was constrained by presence of vacant houses. We discuss how changes in the socioeconomic and agricultural landscape can increase vulnerability to vector-borne illnesses.