Acta tropica最新文献

{"title":"SARS-CoV-2 infection in synanthropic rats from Guayaquil city (Ecuador) during COVID-19 pandemic: A proxy to prevent wild reservoirs in the tropics","authors":"","doi":"10.1016/j.actatropica.2024.107371","DOIUrl":"10.1016/j.actatropica.2024.107371","url":null,"abstract":"<div><p>Human-to-animal reverse transmission of SARS-CoV-2 is a risk for new reservoirs' emergence and new variants' evolution. SARS-CoV-2 infection of synanthropic rodents in urban settings has been reported during COVID-19 in New York and Mexico cities. In this study, we addressed the potential transmission of SARS-CoV-2 to synanthropic rats in the city of Guayaquil (Ecuador) during the COVID-19 pandemic. A total number of 234 rats were collected and analyzed for SARS-CoV-2 detection by RT-qPCR. A positivity rate of 6 % (14 rats) was found, and SARS-CoV-2 infection was confirmed by Sanger sequencing of the viral genome. Our results confirm the potential risk of synanthropic rats as reservoirs for SARS-CoV-2 infection. This is worrisome for low and middle income countries like Ecuador, where pest and waste control in urban settings is challenging. Moreover, the risk of spillover to wild fauna is a concern in Guayaquil, where synanthropic fauna includes raccoons or coatis and forest patches with a wild population of felids or primates existing within the city limits. In this context, SARS-CoV-2 sentinel surveillance of synanthropic rodents could serve as a proxy for a One Health approach to prevent the emergence of new wild reservoirs.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142103232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular identification and genetic variation of forensically important fly species (Order: Diptera) in Thailand using DNA barcoding","authors":"","doi":"10.1016/j.actatropica.2024.107366","DOIUrl":"10.1016/j.actatropica.2024.107366","url":null,"abstract":"<div><p>Forensic entomology plays a crucial role in criminal investigations by providing vital insights into minimum postmortem interval (PMI_min) and corpse relocation by identifying insect species that colonize in decomposing remains. This study aimed to identify and analyze the genetic variation of forensically significant fly species in Thailand, using DNA barcoding of the mitochondrial cytochrome c oxidase subunit I <em>COI</em> gene. A total of 3,220 fly specimens were collected from 18 provinces across six regions of Thailand from October 2017 to September 2022. These specimens were classified by morphological identification into 21 species among three Dipteran families: Calliphoridae, Muscidae, and Sarcophagidae, with <em>Chrysomya megacephala</em> Diptera: Calliphoridae being the most abundant species. DNA barcoding confirmed the morphological identifications with 100 % accuracy, showing low intraspecific K2P distances0.0 to 1.1 %) and significant interspecific K2P distances 2.5 % to 17.2 %. A Neighbour-Joining (NJ) analysis was conducted to assess the molecular identification capabilities of the barcoding region. This analysis successfully recovered nearly all species as distinct monophyletic groups. The species groupings obtained were generally consistent with both morphological and molecular identifications. These findings underscore the effectiveness of DNA barcoding for precise species identification and contribute to a comprehensive database of forensically important flies in Thailand, thus facilitating improved forensic investigations and biodiversity studies.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Successful yeast microencapsulation of fluralaner and its potential as a larvicide for vector control","authors":"","doi":"10.1016/j.actatropica.2024.107358","DOIUrl":"10.1016/j.actatropica.2024.107358","url":null,"abstract":"<div><p>Fly control for any species is most effectively implemented in the immature stages when insects can be eliminated before emerging as adults capable of transmitting pathogens or becoming nuisance pests. Yet a limited number of insecticide classes are available for treating larval development sites for dipteran pest species. The most recently introduced class of insecticides in the United States (US) is the isoxazolines, including fluralaner. In the US, fluralaner is currently exclusively labeled for use against ectoparasites in companion animals. However, research has shown that it has a wider effective target range beyond ectoparasites and could be developed as an insecticide for vector control. Here we tested a novel, proprietary, yeast microencapsulated (YME) formulation of fluralaner against the larvae of three pest species: <em>Musca domestica</em> L. (Diptera: Muscidae), <em>Aedes albopictus</em> Skuse (Diptera: Culicidae)<em>,</em> and <em>Culicoides sonorensis</em> Wirth and Jones (Diptera: Ceratopogonidae)<em>.</em> These species all naturally consume microorganisms as larvae, including yeasts. Fluralaner was successfully microencapsulated in <em>Saccharomyces cerevisiae</em> yeast. YME fluralaner was reconstituted in water at concentrations of 0.00001–0.1 mg/mL (<em>Aedes</em> and <em>Culicoides</em>) or 1–50 mg/mL (<em>Musca</em>) for use in dose-response assays. For each species, the LC₅₀ at 24 h was estimated using probit analyses. YME fluralaner was highly effective against all species tested (<em>Ae. albopictus</em> LC₅₀ = 0.000077 mg/mL; <em>C. sonorensis</em> LC₅₀ = 0.00067 mg/mL; <em>M. domestica</em> LC₅₀ = 2.58 mg/mL). Additionally, laboratory assays were conducted to determine product reapplication rates using LC₅₀ rates. Reapplication rates to maintain &lt;50 % emergence were five weeks (<em>Ae. albopictus</em>) and greater than eight weeks (<em>C. sonorensis</em>). The results presented here indicate YME fluralaner is a promising candidate for controlling larval insects that naturally feed on detritus, thereby bypassing cuticular penetration barriers and safely delivering the active ingredient to the target species.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing and synchronizing Aedes aegypti colony for Sterile Insect Technique application: Egg hatching, larval development, and adult emergence rate","authors":"","doi":"10.1016/j.actatropica.2024.107364","DOIUrl":"10.1016/j.actatropica.2024.107364","url":null,"abstract":"<div><p>Mosquito Sterile Insect Technique (SIT) programs can be developed in smaller agencies through synchronization of the colony development to take advantage of the natural male early emergence. This paper examined key aspects of <em>Ae. aegypti</em> colony synchronization work, including egg hatching, larval development, and adult emergence to produce sufficient numbers of adult male mosquitoes within a specific timeframe for irradiation and release. Our data indicated that a relatively low percentage of males are required for colony propagation. Additional results highlighted that fresher <em>Ae. aegypti</em> eggs could yield as high as a 93 % hatching success than older eggs when placed under vacuum pressure in yeast infused water for 1.5 h. Eggs that were one-month old hatched (93 %) better than older eggs (0–32 %). A higher egg density in the hatching flask was correlated to a lower hatch rate, and higher larval density was related to unsynchronized pupae and delayed adult emergence. By keeping <em>Ae. aegypti</em> larvae at reasonable density, over 95 % of adults emerged on the first two days of emergence – indicating a high synchronicity. A standardized colony maintenance protocol therefore renders a synchronized larval development and adult male emergence which are critical in SIT programs.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A baited trap for kissing bugs (Hemiptera: Reduviidae: Triatominae)","authors":"","doi":"10.1016/j.actatropica.2024.107368","DOIUrl":"10.1016/j.actatropica.2024.107368","url":null,"abstract":"<div><p>Chagas disease is a key vector-borne disease. This illness is caused by <em>Trypanosoma cruzi</em> Chagas, which is transmitted by triatomine bugs. Largely, the control of this disease relies on reducing such contact. We optimized the performance of a box trap in laboratory conditions to capture four triatomine species: <em>Triatoma pallidipennis</em> (Stål)<em>, Triatoma infestans</em> Klug<em>, Triatoma phyllosoma</em> (Burmeister), and <em>Rhodnius prolixus</em> Stål. We varied four components for a box trap: material, color, height, and bait attractants. All species were captured more in corrugated cardboard traps than in other trap material. Moreover, <em>T. infestans</em> and <em>R. prolixus</em> were also captured in plywood traps. <em>T. pallidipennis</em> preferred traps of 15 × 15 × 4 cm and 20 × 20 × 4 cm, while <em>T. phyllosoma</em> and <em>T. infestans</em> were more captured in traps of 10 × 10 × 4 cm, and 15 × 15 × 4 cm. <em>Rhodnius prolixus</em> was more captured to 10 × 10 × 4 cm traps. <em>T. pallidipennis</em> was trapped with traps of any color tested, <em>T. phyllosoma</em> and <em>T. infestans</em> were captured more in red and yellow traps, and <em>R. prolixus</em> was mostly captured in blue, violet, and yellow traps. <em>Triatoma pallidipennis</em> was captured at any height above the ground, while <em>T. phyllosoma, T. infestans</em>, and <em>R. prolixus</em> were mostly captured 50, 100, and 150 cm above the ground. Regarding the lure, <em>T. pallidipennis</em> was trapped with four aldehydes + lactic acid + ammonia; <em>T. infestans</em> and <em>R. prolixus</em> were trapped with a blend of four aldehydes + lactic acid, a blend of the four aldehydes + ammonia, and a blend of four aldehydes + lactic acid + ammonia. <em>Triatoma phyllosoma</em> was trapped with any lure tested. These results showed that the trap boxes offer an alternative method for controlling Chagas disease.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy of the Dual Path Platform (DPP) rapid test for the diagnosis of leptospirosis: A multi-center study in six Brazilian states","authors":"","doi":"10.1016/j.actatropica.2024.107361","DOIUrl":"10.1016/j.actatropica.2024.107361","url":null,"abstract":"<div><p>Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the overlooked: Current and future distribution dynamics of kissing bugs and palm species linked to oral Chagas disease transmission","authors":"","doi":"10.1016/j.actatropica.2024.107367","DOIUrl":"10.1016/j.actatropica.2024.107367","url":null,"abstract":"<div><p>Chagas disease, a neglected global health concern primarily transmitted through the bite and feces of kissing bugs, has garnered increasing attention due to recent outbreaks in northern Brazil, highlighting the role of oral transmission facilitated by the kissing bugs species <em>Rhodnius robustus</em> and <em>Rhodnius pictipes</em>. These vectors are associated with palm trees with large crowns, such as the maripa palm (<em>Attalea maripa</em>) and moriche palm (<em>Mauritia flexuosa</em>). In this study, we employ maximum entropy (MaxEnt) ecological niche models to analyze the spatial distribution of these vectors and palm species, predicting current and future climate suitability. Our models indicate broader potential habitats than documented occurrences, with high suitability in northern South America, southern Central America, central Africa, and southeast Asia. Projections suggest increased climate suitability by 2040, followed by a reduction by 2080. This study identifies present and future areas suitable for kissing bugs and palm tree species due to climate change, aiding in the design of prevention and management strategies.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to: “Echinococcus granulosus promotes bone resorption by increasing osteoclasts differentiation” [Acta Tropica, volume 248, article number 107027]","authors":"","doi":"10.1016/j.actatropica.2024.107314","DOIUrl":"10.1016/j.actatropica.2024.107314","url":null,"abstract":"","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0001706X24001967/pdfft?md5=c8684ae3b9876494ac4de5fa9bd37f34&pid=1-s2.0-S0001706X24001967-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ovicidal activity of diaryl dichalcogenides and ivermectin on Fasciola hepatica: A novel candidate for a blending-based therapeutic strategy","authors":"","doi":"10.1016/j.actatropica.2024.107363","DOIUrl":"10.1016/j.actatropica.2024.107363","url":null,"abstract":"<div><p>Fasciolosis is a food and waterborne disease caused by <em>Fasciola</em> spp., representing a global health burden to various hosts, including humans and other animals. This study investigates the <em>in vitro</em> activity of tellurium- and selenium-containing diaryl dichalcogenides: diacetal ditelluride (LQ07), diacetal diselenide (LQ62), and diacetyl diselenide (LQ68) alone and in combination with ivermectin (IVM) against eggs of <em>Fasciola hepatica</em>. The eggs were exposed for 12 h with each organochalcogen (OC) (0.1 - 2 mmol <span>l</span>^-1) and IVM (0.01 - 2 mmol <span>l</span>^-1) following an incubation of 15 days, allowing embryonation. The inhibitory concentration of 50 % (IC₅₀) of each OC or IVM was tested with the IC₁₀, IC₃₀, and IC₅₀ of IVM or each OC, respectively. LQ07, LQ62, and LQ68, as well as IVM, demonstrated a concentration-dependent ovicidal activity. The peak ovicidal activity of 99.74 % was achieved when IVM was tested at 2.0 mmol <span>l</span>^-1. LQ62 and LQ68 demonstrated greater ovicidal activity, having an IC₅₀ &lt; 0.32 mmol <span>l</span>^-1 being 6.25-fold more toxic than IVM alone. The percentage of dead eggs was significantly higher in the IVM group (early mortality), as Se-containing OCs led to the (miracidia) embryonation of the eggs with no hatching (late mortality). Blending Se-containing OCs and IVM showed an additive effect of up to 27 % against <em>F. hepatica</em> eggs. The present data contribute to the potential use of blending-based therapeutic strategies to combat <em>F. hepatica</em> infections in eradication programs worldwide. The combinations may also act against multidrug-resistant strains, reinstating drug-based parasite control.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"microRNA profiling of exosomes derived from plasma and their potential as biomarkers for Opisthorchis viverrini-associated cholangiocarcinoma","authors":"","doi":"10.1016/j.actatropica.2024.107362","DOIUrl":"10.1016/j.actatropica.2024.107362","url":null,"abstract":"<div><p>Cholangiocarcinoma (CCA) is a life-threatening disease that impacts patients worldwide. In Southeast Asian countries, the liver fluke <em>Opisthorchis viverrini</em> plays a major role in inducing carcinogenesis of the bile ducts. Due to its asymptomatic nature, <em>O. viverrini</em> infections are rarely treated, consequently leading to the development of advanced stages of CCA before diagnosis. Despite the current use of exosomal microRNAs (miRNA) as diagnostic biomarkers for the early detection of many types of cancer, the applications for miRNA remain limited with CCA. Circulating exosomes, membranous vesicles essential for intercellular communication, were found to contain unique miRNA. In this study, we conducted next-generation sequencing (Ion Torrent PGM) and bioinformatics to characterize and compare the contents of exosomal miRNA derived from the plasma of CCA patients, <em>O. viverrini</em>-infected patients, and healthy individuals, as well as to identify and validate key molecules as markers for screening the diagnosis of CCA and <em>O. viverrini</em> infection. The obtained results showed the success of using NGS technology in discovering exosomal miRNAs, specifically miR-194–5p and miR-192–5p, both of which were upregulated in the <em>O. viverrini</em>-infected group. Interestingly, miR-192–5p was upregulated while miR-194–5p was downregulated in CCA, suggesting their potential use as biomarkers for screening CCA and <em>O. viverrini</em> infection, especially in O<em>. viverrini</em>-endemic areas.</p></div>","PeriodicalId":7240,"journal":{"name":"Acta tropica","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}