Search Results (151)

Wild animals play an important role in the epidemiological cycle of Trypanosoma cruzi transmission. The order Chiroptera is ecologically significant as a reservoir host for parasite variants, including TcI, TcII, TcIV, and TcBat. This study aimed to detect T. cruzi in multiple organs of Desmodus rotundus from two regions of San Luis Potosí, Mexico. A total of 63 D. rotundus samples were obtained, of which 22.2% (14/63) tested positive for T. cruzi infection. The highest infection rate was observed in the Media region, with 47.3% (9/19) of samples being infected, whereas in the Huasteca region 11.3% (5/44) of samples were infected. Infection prevalence did not differ significantly by sex or age. Of the five organs tested, only the intestine and the kidney were positive. Phylogenetic and genetic distance analyses revealed sequence identity values >98% with TcI/Tbat trypanosomes. These findings add to the growing body of evidence that bats, particularly hematophagous species such as D. rotundus, play a significant role in maintaining T. cruzi in sylvatic environments and potentially facilitating transmission at the wildlife–domestic interface. Continuous surveillance integrating bat populations, vectors, humans, and domestic animals is essential for understanding and mitigating the risk of Chagas disease in regions where sylvatic and domestic transmission cycles overlap. Full article

Climate change is significantly altering the distribution, seasonality, and transmission dynamics of vector-borne diseases, posing an increasing public health concern, particularly in regions previously considered at low risk. Key climatic variables, including temperature, precipitation, and humidity, strongly influence vector survival, reproduction, and pathogen transmission capacity. This review provides an overview of current evidence on the relationship between climate change, vector ecology, and vector-borne disease epidemiology in Europe, based on evidence extracted from peer-reviewed literature published between 2010 and 2024 and retrieved from PubMed, Scopus, and Web of Science. Particular attention is given to vector-borne diseases with current or potential relevance to Europe. This includes infections that are already endemic, such as leishmaniasis and tick-borne encephalitis, as well as diseases currently imported, such as malaria, dengue, chikungunya, Zika, yellow fever, and Chagas disease, that may pose a future risk of local transmission due to climate-driven changes in vector distribution and abundance. The analysis highlights potential health and economic impacts, and discusses implications for public health preparedness, environmental sanitation, surveillance, and vector control strategies. Strengthening adaptive and mitigation policies, alongside targeted research efforts, is essential to enhance resilience of health systems against climate-driven epidemic risks. Full article

Different protozoan parasites are the causative agents of tropical diseases, including malaria, toxoplasmosis, leishmaniasis, and Chagas disease (CD), which, altogether, affect over 300 million people throughout the world. Except for two recently approved malaria vaccines, individuals affected by or at risk of contracting any of these four diseases still experience a lack of effective treatments and vaccines. Many vaccine studies, including those that have reached clinical trials, are based on inactivated parasites, adjuvanted recombinant proteins, or viral vector vaccines. Here, we review the current advances towards the development of vaccines based on genetically modified live-attenuated parasites (GMLAP) as well as RNA formulations encoding parasite antigens. Because these are diseases caused by intracellular pathogens that depend on efficient T-cell responses for parasite control, these two new vaccine platforms have generated great expectations, since they are known to induce a robust cellular immune response. Although preclinical studies aimed at developing new malaria, toxoplasmosis, and leishmaniasis vaccines have led to significant progress that may soon result in clinical trials, advances in next-generation vaccines against CD are lagging behind. Increased collaborative efforts between research groups, governments, and the pharmaceutical industry, particularly in Africa, Asia, and Latin American countries, are urgently needed to accelerate the development of vaccines for all neglected and less-studied diseases. Full article

Food deprivation induces intestinal adaptations in Triatoma pallidipennis, a hematophagous insect with intermittent feeding habits. The ability to survive long periods without food promotes the persistence of this vector in the environment and contributes to its evolutionary success. This study employed one- and two-dimensional electrophoretic techniques combined with Western blot to evaluate the abundance of α-tubulin, β-actin, and the heat shock protein HSP70. These proteins were more abundant in the anterior midgut tissue of unfed insects than in that of fed insects. As these responses were similar in females and males, the observed adaptations primarily depend on feeding status and intestinal region. These findings provide further insight into the intestinal physiology of T. pallidipennis, a vector of the flagellate parasite Trypanosoma cruzi, the causative agent of Chagas disease. Full article

Chagas disease, caused by Trypanosoma cruzi, affects 7 million people. Studying the ecology of triatomine vectors through midgut content analysis allows for infection diagnosis and the identification of blood meal sources (BMSs). Current BMS methodologies are limited by the accuracy of genetic data for local fauna, limiting species identification of hosts involved in parasite transmission. Here, we performed a systematic review on BMSs of T. cruzi vectors and showed the geographical distribution by T. cruzi lineages and vertebrate orders. We propose a decision tree system combining ecological and taxonomic approaches (EcoTaxDT) to discriminate ambiguous BMS results. The EcoTaxDT was validated using published and new BMS results. The review highlights the growing number of BMS studies and the awareness of host species potentially involved in transmission cycles. In Brazilian studies, EcoTaxDT allowed for taxonomic assignments when genetic identity was insufficient or when identified taxa had no geographical occurrence. New BMS results, validated by EcoTaxDT, showed triatomines feeding on Natalus macrourus, Echimyidae, Tettigoniidae, and Tropidurus itambere. Reliable BMS data and T. cruzi diagnosis are crucial for understanding transmission dynamics and human infection risk. EcoTaxDT is functional in correcting inconsistent BMS outputs, ensuring robust and consistent results by integrating genetic, taxonomy, and species geographical distribution. Full article

Chagas disease, caused by Trypanosoma cruzi, is maintained in nature by complex interactions among wild vertebrates and triatomine insect vectors, yet the role of many introduced hosts remains poorly resolved. Here, we assessed natural T. cruzi infection in wild European rabbits (Oryctolagus cuniculus) from central Chile, where introduced rabbits overlap ecologically with the sylvatic vector Mepraia spinolai. Eight free-ranging rabbits captured in Las Chinchillas National Reserve were evaluated using an integrative diagnostic approach combining xenodiagnosis with laboratory-reared, parasite-free M. spinolai nymphs, real-time polymerase chain reaction targeting T. cruzi satellite DNA in blood and 12–14 organs per animal, and histopathology with immunohistochemistry (anti-cruzipain) to identify tissue parasite forms. Blood molecular detection was positive in seven out of eight rabbits, while xenodiagnosis detected viable parasites in two out of seven evaluated individuals. Organ molecular screening detected T. cruzi DNA in at least one organ in all rabbits, with frequent positivity in the diaphragm, reproductive tissues, spleen, and kidney. Histopathology identified parasite forms in four out of eight animals, and immunohistochemistry confirmed hepatic amastigotes in one case. These findings provide multi-method evidence of natural infection in the sampled individuals, including evidence of parasite viability in some individuals, suggesting potential epidemiological relevance within this ecological context and possible utility for surveillance in Chilean sylvatic transmission settings. Full article

Chagas disease remains a major public health concern in Latin America, with Bolivia reporting one of the highest burdens of infection. While congenital transmission has become the predominant route of new infections in several countries, vector-borne transmission persists in rural and peri-urban regions. Postrervalle, in the department of Santa Cruz, is officially classified as a low-infestation area; however, updated community-level data remain limited. We conducted a cross-sectional study in July 2023 involving 58 mothers and 104 of their children in Postrervalle. Participants underwent serological screening with three diagnostic assays, and epidemiological data were collected via structured maternal questionnaires. Logistic regression models were used to assess associations between child Trypanosoma cruzi seropositivity and maternal or household exposures during pregnancy. Seroprevalence was 15.5% among mothers and 3.8% among children. Notably, all seropositive children were born to mothers who tested seronegative, suggesting non-congenital transmission. In multivariable analysis, living in houses with mud walls during pregnancy was strongly associated with child seropositivity (adjusted OR = 38.566), while older child age also increased the odds of infection. Other maternal exposure variables showed elevated but imprecise associations. Despite its classification as a low-infestation area, Postrervalle shows serological patterns consistent with postnatal acquisition linked to domestic structural conditions that facilitate triatomine colonization. These findings overall highlight the need for integrated serological and entomological surveillance to better characterize and prevent Chagas transmission in rural communities. Full article

The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected tropical disease that mostly affects the population of Latin American countries, with an estimated 7 million infected people and more than 10,000 deaths per year worldwide. T. cruzi is typically transmitted by hematophagous triatomine insects, with Rhodnius prolixus being a major insect vector in South America. While the microbiome of triatomine insects has been investigated to a certain extent, the ternary interaction between triatomes insects, T. cruzi, and viruses remains virtually unexplored. In this study, we show by transmission electron microscopy and by RT-PCR that Rhodnius prolixus viruses (RpVs) can infect the intestine of R. prolixus, which places them in close contact with the gut microbiota. These observations suggest that T. cruzi can be infected by the insect viruses while transiting through the gut. Here, we show that the RpVs are capable of infecting the epimastigote forms of T. cruzi in vitro and maintain the viral load stabilized for 3 to 7 days after infection. We also show that, at least in the case of the iFlavirus RpV1, viral genomes are detectable in the T. cruzi cytoplasm. Interestingly, R. prolixus ovarian extracts enriched with RpVs decrease epimastigote proliferation and their capacity for differentiation into the ineffective metacyclic trypomastigotes in vitro. Our results start to shed light on the interaction between RpVs and T. cruzi, suggesting possible routes of infection and unveiling a role for viral infections in the development of this important pathogen. Full article

Background: Chagas disease, caused by Trypanosoma cruzi, remains endemic throughout Latin America but is increasingly reported in urban areas due to migration and vector adaptation. The cardiac form is the most severe manifestation, associated with arrhythmia, mural thrombus formation, and a high risk of cardioembolic events. Stroke secondary to Chagas cardiomyopathy is uncommon and poses diagnostic and therapeutic challenges. Case Presentation: A 58-year-old woman with serologic evidence of T. cruzi infection presented with sudden-onset dyspnea, oppressive chest pain, and left-sided weakness. Neurological examination revealed left brachiocrural hemiparesis and mild dysarthria (NIHSS = 9). Non-contrast cranial CT showed an acute infarct in the right middle cerebral artery territory (ASPECTS = 7). Electrocardiography demonstrated typical atrial flutter with variable conduction, and transthoracic echocardiography revealed a markedly dilated left atrium containing a mural thrombus and a left ventricular ejection fraction of 45%. Intravenous thrombolysis with alteplase (0.9 mg/kg) was administered within 4.5 h of symptom onset. Pharmacologic rhythm control was achieved using intravenous and oral amiodarone, followed by oral anticoagulation with warfarin (target INR 2.0–3.0) after excluding hemorrhagic transformation. The patient showed rapid neurological improvement (NIHSS reduction from 9 to 2) and was discharged on day 10 with minimal residual deficit (mRS = 1), sinus rhythm, and stable hemodynamics. Conclusions: This case highlights the rare coexistence of Chagas cardiomyopathy, atrial flutter, and cardioembolic stroke due to left atrial thrombus. Early recognition, adherence to evidence-based guidelines, and multidisciplinary management were key to achieving a favorable outcome. Timely diagnosis and intervention remain crucial to preventing severe complications in patients with Chagas disease. Full article

Vector-borne parasites might be transmitted through transfusion, notably Plasmodium spp. and Trypanosoma cruzi. Prevention strategies include blood donor screening, deferral, and blood unit treatment by pathogen inactivation methods. At the end of 2015, in line with European guidelines, Italian legislation introduced a questionnaire to identify donors at risk and their screening by serological methods. In early 2016, the Laboratory of Parasitology at Pisa University Hospital started the serological analysis of donors at risk, referring to Transfusion Services located in northwestern Tuscany. The aim of the present study was to describe the prevalence of seropositive donors observed during 8 years of screening. Donors at risk of transmitting malaria were screened by ELISA (Enzyme Linked Immunosorbent Assay). The DRG ELISA kit was employed until 2020, when it was substituted by the Euroimmun ELISA kit based on the results of a comparative evaluation of available commercial kits. Seropositive donors were offered the possibility of Plasmodium DNA testing by Loop-Mediated AMPlification (LAMP) to exclude current infection. Donors at risk of transmitting Chagas disease were screened by ICT employing recombinant antigen until 2021, when it was substituted by ELISA employing lysate antigen because of its higher accuracy. Seropositive donors were further tested by CLIA, and WB was performed in case of discordant results, according to WHO guidelines for diagnosis of chronic Chagas disease. A total of 3754 donors were tested for anti-Plasmodium antibodies, revealing a 6.8% (95% CI = 6.1–7.7%) seroprevalence. Seropositivity was higher among donors from Sub-Saharan Africa (42.9%; 95% CI = 36.1–49.9%) and Southeast Asia (10.6%; 95% CI = 6.7–16.4%). A lower seropositivity was observed when employing Euroimmun ELISA (4.8; 95% CI = 3.8–5.9%) than DRG ELISA (8.2%; 95% CI = 7.1–9.3%). Seropositivity dropped to 3.6% (95% CI = 2.4–5.6) in 2020, likely because of travel restrictions during the COVID-19 pandemic. None of the tested seropositive donors (n = 20) tested positive for Plasmodium DNA LAMP testing. A high proportion of seroreversion was observed after one year of testing. Among 4285 donors tested for anti-T. cruzi antibodies seroprevalence was 0.7% (95% CI = 0.5–1.1%), a higher value than what was observed in a recent national survey. All seropositive donors were born in Europe or Latin America. Seropositivity was apparently lower with ELISA (0.5%, 95% CI = 0.2–1.2%) than ICT (0.8%, 95% CI = 0.6–1.2%), possibly due to ELISA’s higher specificity, although the difference is not significant. No confirmed cases of chronic Chagas disease were identified. The study emphasizes the importance of defining the serological test employed for screening and the need to confirm seropositive results with further testing. The high seroreversion observed in the study suggests repeating seropositive donor screening after a year to minimize deferral and blood unit loss. Full article

The growing environmental pollution and the imminent depletion of natural resources highlight the need for alternative building materials derived from renewable sources, including those that promote waste recycling and biodegradability. One promising alternative is biocomposites produced from filamentous fungal mycelium. In Argentina, orange and lemon peels are among the most abundant organic waste generated by the citrus industry. This study explores the development of a sustainable insulating biocomposite using Pleurotus ostreatus mycelium grown on mixtures of citrus peels, paper, and cardboard. The test specimens were prepared using varying concentrations of these components. The resulting fungal biocomposite exhibited a density approximately ten times higher than expanded polystyrene, with drying shrinkage ranging from 28% to 51%, depending on the formulation. Key properties were evaluated, including compressive strength (${\sigma }_{10}$ = 7–33 kPa), bulk density ($\rho$ = 152–181 kg/m³), and thermal conductivity ($\lambda$ = 0.29–0.36 W/mK), indicating advantageous performance for thermal insulation in construction applications. Specimens containing orange peel also demonstrated repellent activity against Triatoma infestans, main vector of transmission of Chagas’ disease, attributed to the residual limonene content retained from the citrus peels. This fungal biocomposite aligns with principles of green chemistry and circular economy, offering a biodegradable, low-impact solution with potential use in construction. The citrus waste proved to be an effective substrate for mycelial growth, producing a material with desirable mechanical and thermal properties, and added resistance to biodeterioration. Full article

Chagas disease (CD), caused by the parasite Trypanosoma cruzi, remains one of the most important neglected tropical diseases. Historically confined to rural areas of Latin America, the disease has now become a global health challenge due to increased migration, urbanization, and ecological changes. This review explores how patterns of transmission and endemicity have evolved, emphasizing the emergence of new geographic hotspots and non-traditional routes of transmission, such as congenital and oral infections. We integrate evidence from ecological studies showing how deforestation, urban sprawl, and climate change are reshaping vector habitats and influencing the spread of triatomine insects. Furthermore, we highlight advances made between 2020 and 2025 in key research areas, including vector genomics and climate-based predictive mapping, as well as digital surveillance strategies that leverage machine learning and citizen science. These innovations provide valuable insights for predicting future risks and improving disease control. By linking global epidemiological trends, ecological drivers, and cutting-edge scientific advances, this review underscores the urgent need for integrated, collaborative strategies to prevent further spread and to protect vulnerable populations worldwide. Full article

Annona muricata (soursop) produces secondary metabolites with antimicrobial and insecticidal properties. Arbuscular mycorrhizal fungi (AMF) are known to enhance the production of secondary metabolites in medicinal plants. In this study, we aimed to evaluate the insecticidal activity of ethanolic leaf extracts from AMF-colonized soursop trees against the fall armyworm (Spodoptera frugiperda) and the triatomine bug Triatoma pallidipennis, a vector of Chagas disease. Ethanolic leaf extracts were obtained from trees inoculated with two AMF consortia (Cerro del Metate and Agua Dulce), with the species Rhizophagus intraradices and Funneliformis mosseae, and from non-mycorrhizal plants (SM). Extracts were tested in bioassays specific to each insect, including chemical and negative controls, and survival was analyzed using Kaplan–Meier curves. Extracts from plants colonized by F. mosseae exhibited insecticidal activity against S. frugiperda, causing 72% larval mortality, comparable to that of the commercial insecticide. In contrast, extracts from plants inoculated with the Agua Dulce consortium caused 65% mortality in T. pallidipennis adults. These extracts showed significantly higher annonacin content (µg·g⁻¹ DW). Overall, the results demonstrate that AMF colonization can enhance the synthesis of metabolites such as annonacins and contribute to increased insecticidal activity in A. muricata. Our findings suggest AMF-assisted cultivation has the potential to enhance botanical insecticides. Full article

Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits remarkable developmental plasticity that enables its survival across distinct environments within the insect vector and mammalian host. This review focuses on two critical differentiation processes—metacyclogenesis and epimastigogenesis—emphasising their environmental triggers, metabolic regulation, and roles in parasite transmission and life cycle progression. Metacyclogenesis, occurring in the hindgut of triatomine vectors, transforms replicative epimastigotes into infective metacyclic trypomastigotes and is tightly controlled by factors such as nutrient starvation, pH, and temperature. In contrast, epimastigogenesis allows trypomastigotes to revert to epimastigote forms, primarily in the vector midgut, as part of the parasite’s adaptation to vector colonisation. We compare these processes through the lens of stress-induced signalling and proteomic reprogramming, highlighting their metabolic divergence and ecological significance. Emerging evidence also suggests that extracellular vesicles (EVs) released by different parasite forms may actively modulate these transitions, supporting parasite communication and immune evasion strategies. A better understanding of these transitions provides novel insight into parasite adaptation and reveals potential molecular targets for disrupting the life cycle of T. cruzi. Full article

Trypanosoma cruzi is the etiological agent of Chagas disease, traditionally transmitted by triatomine vectors. However, experimental and clinical evidence suggest a possibility that the parasite could also be transmitted sexually. In animal models, T. cruzi amastigotes and trypomastigotes have been identified in reproductive tissues and semen, and infection has been experimentally transmitted between mating partners. In humans, the presence of the parasite in menstrual blood, semen, and other genital secretions has been reported, raising the possibility of sexual transmission in both endemic and non-endemic settings. This potential route could contribute to the persistence of infection and the development of congenital cases. Here, we review the current evidence supporting the biological plausibility and experimental demonstration of sexual transmission of T. cruzi, and highlight key research priorities to clarify its clinical and epidemiological significance. Full article