PLoS Neglected Tropical Diseases最新文献

{"title":"IL-18 favors Th2 responses in sporotrichosis caused by Sporothrix globosa, prolonging the course of the disease.","authors":"Henan Si, Yan Cui, Jianjiao Zu, Ying Shi, Yang Song, Yu Zhen, Shanshan Li","doi":"10.1371/journal.pntd.0013170","DOIUrl":"10.1371/journal.pntd.0013170","url":null,"abstract":"<p><strong>Background: </strong>Sporotrichosis is a subcutaneous mycosis caused by members of the genus Sporothrix, among which Sporothrix globosa (S. globosa) is the predominant etiological agent in Asia. T cell immunity plays crucial roles in fungal infections, yet the local T cell immune profile in sporotrichosis lesions remains unclear. IL-18, a pleiotropic cytokine capable of modulating T cell responses, is also poorly understood in host defense against S. globosa.</p><p><strong>Methodology/principal findings: </strong>qPCR, western blot, and IHC/mIHC were employed to profile IL-18, IL-18 BP, caspase-1 and IL-18R axis, along with Th1,Th2, and Th17 cells and their specific cytokines in sporotrichosis lesions versus healthy skin. Cellular sources of IL-18 in the lesions were identified via mIHC, and IL-18 production from keratinocyte/PBMCs exposed to S. globosa in vitro was tested by qPCR and western blot. Flow cytometry was performed to evaluate the role of IL-18 in Th2 polarization in the PBMCs-S. globosa coculture system. Lesional skin exhibited hyperactivated IL-18 signaling, marked by upregulated IL-18, caspase-1, and IL-18R, alongside decreased IL-18 BP. IL-18 was primarily released by dermal dendritic cells and Langerhans cells, rather than keratinocytes. A mixed Th1/Th2/Th17 microenvironment with Th2 predominance correlated strongly with prolonged disease duration. Strikingly, IL-18 synergistically interacted with Th1-derived IL-2 to establish a self-reinforcing Th2 loop, as evidenced by the strong correlation between lesional IL-4 and IL-18 levels (r = 0.70) and the concomitant upregulation of IL-18/IL-2 during S. globosa-induced Th2 expansion in PBMCs-an effect reversed by IL-18/IL-2 neutralizing antibodies. Critically, this Th2 skewing was mechanistically dependent on NF-κB signaling, as demonstrated through pharmacological pathway inhibition.</p><p><strong>Conclusions/significance: </strong>This study unveils the dual role of IL-18 in human sporotrichosis caused by S. globosa-amplifying both Th1 and Th2 responses but ultimately driving pathogenic Th2 polarization through IL-2 crosstalk. Our work identifies IL-18/IL-2/NF-κB axis as a key Th2-polarizing mechanism driving chronicity in this disease. Targeting this axis could recalibrate anti-fungal immunity, offering translational strategies for this subcutaneous disease.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013170"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173405/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative multi-pathway assessment of exposure to Escherichia coli for infants in Rural Ethiopia.","authors":"Yuke Wang, Yang Yang, Crystal M Slanzi, Xiaolong Li, Amanda Ojeda, Fevi Paro, Loïc Deblais, Habib Yakubu, Bahar Mummed Hassen, Halengo Game, Kedir Teji Roba, Elizabeth Schieber, Abdulmuen Mohammed Ibrahim, Jeylan Wolyie, Jemal Yusuf Hassen, Gireesh Rajashekara, Sarah L McKune, Arie H Havelaar, Christine L Moe, Song Liang","doi":"10.1371/journal.pntd.0013154","DOIUrl":"10.1371/journal.pntd.0013154","url":null,"abstract":"<p><p>In low- and middle-income countries (LMICs), enteric infections pose a significant threat to children's health. However, understanding the specifics of when, where, and how young children in LMICs are exposed to enteric pathogens and the roles of animal reservoirs, environmental media, and human hosts play during exposure remains limited. This study systematically evaluates infants' exposure to E. coli through various pathways in the rural Haramaya woreda of Ethiopia. Between June 2021 and June 2022, we conducted over 1300 hours of structured behavioral observations on 79 infants when aged 4-8 months (Timepoint 1) and 11-15 months (Timepoint 2). Enumerators recorded the infant's behavior related to exposure, including when and where it occurred, using a data collection system for behavioral data (Countee). Concurrently, we collected 1338 environmental samples from key contact interfaces between infants, other people, and the environment to test for E. coli. We used a competing hazard model for duration-based behaviors, an inhomogeneous Poisson point process model for frequency-based behaviors, and a left-censored lognormal distribution model for E. coli contamination levels. The behavioral and environmental information was then integrated into an agent-based exposure model framework to quantify the exposure to E. coli through different pathways. The infant behavior, which altered the relative importance of different exposure pathways, changed as children grew older. Notably, we observed increased rates of touching behavior (e.g., touching fomites) and soil-pica, increased consumption of solid food, and more time spent on the bare ground at Timepoint 2. The major sources of exposure to E. coli were food and breastfeeding at Timepoint 1 and food and soil at Timepoint 2. This study provides insights for interventions to minimize infants' risk of exposure to fecal indicator bacteria, E. coli, and subsequent risk of enteric infections, including improved food handling practices, enhanced personal hygiene for breastfeeding caregivers, and education on the risk of soil-pica.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013154"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12176293/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demographic, temporal, and spatial analysis of human animal bite cases in Mymensingh District, Bangladesh.","authors":"Chandra Shaker Chouhan, Abu Raihan, Md Manik Mia, Subarna Banerjee, Ishmam Shahriar, Proggananda Nath, Jasim M Uddin, Md Amimul Ehsan, Michael P Ward, A K M Anisur Rahman","doi":"10.1371/journal.pntd.0012204","DOIUrl":"10.1371/journal.pntd.0012204","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to analyze the demographic, temporal, and spatial characteristics of animal bite (AB) cases in humans across 12 Upazilas within Mymensingh district of Bangladesh.</p><p><strong>Methods: </strong>Retrospective hospital-based data from individual AB cases for 2022 and 2023 were collected from S.K Hospital. The dataset included information on victim demographics, bite details, vaccination information, and Rabies Immune Globulin (RIG) administration. Additionally, monthly case counts from 2016 to 2024 were sourced and analyzed to identify trends. Descriptive statistics and time series analysis using the seasonal decomposition technique were conducted. Risk maps for animal bites in 2022 and 2023 were generated using a standardized incidence ratio (SIR) approach.</p><p><strong>Findings: </strong>An almost two-fold increase in the proportion of category 3 bites receiving RIG from 3.6% in 2022 to 6.5% in 2023 was noted. Only 9.7% (2022) and 16.9% (2023) of bite victims received PEP on the day of exposure, whereas 76.5% (2022) and 84.6% (2023) received PEP within 24 hours. Moreover, significant seasonal patterns and annual increasing trends in AB cases were observed. Males and children under 14 years old had a higher risk of being bitten. Dogs (48.2% in 2022) and cats (52.6% in 2023) were identified as the primary animals responsible for the bites. Notably, the legs were the body part most frequently bitten. The bites risk map identified four high risk Upazilas.</p><p><strong>Conclusion: </strong>Despite improvements in PEP coverage achieved within 24 hours, a critical gap remains in same-day PEP coverage in both years. The study results also suggest other potential improvements in healthcare practices or treatment protocols, and the need for a veterinary surveillance system. Increasing AB cases highlight the need to enhance surveillance and control measures. Targeted awareness campaigns tailored to high-risk groups such as males and children under 14 years of age, along with preventive programs focused on dogs are imperative. Coordinated One Health efforts among healthcare professionals, veterinarians, policymakers, and community stakeholders are crucial to effectively mitigate the incidence of AB cases, safeguarding public health and eliminate dog mediated rabies by 2030 in the region.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0012204"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173383/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Human tick biting and tick-borne disease risk in Türkiye: Systematic review.","authors":"Salar Zarrabi Ahrabi, Fatihan Pınarlık, Gürkan Akyıldız, Mert Kuşkucu, Sırrı Kar, Önder Ergönül, Ayşen Gargılı Keleş","doi":"10.1371/journal.pntd.0013092","DOIUrl":"10.1371/journal.pntd.0013092","url":null,"abstract":"<p><p>Ticks serve as significant vectors for over 100 pathogens, many of which pose serious health risks to humans. Türkiye's diverse tick species and ideal ecological conditions facilitate their proliferation. Following the emergence of the Crimean-Congo Hemorrhagic Fever (CCHF) epidemic in 2004, tick-borne diseases have become a critical public health concern. This systematic review was conducted to identify the dominant tick genera and species responsible for human bites and tick-borne diseases. PubMed, Cochrane, Scopus, Web of Science, Medline, Tübitak TR Dizin, Dergi Park databases were searched following PRISMA guidelines, and the last search was performed on 11 October 2024. Studies reporting human-biting ticks were included and studies that do not report tick species or number of ticks were excluded. A novel quality assessment scale was developed by Türkiye Infectious Diseases (TEH) Vector-Borne Infections Study Group and used for risk of bias assessment. The total number of ticks and percentages were calculated. A total of 24 studies documented 53,879 ticks, 96.60% of which were identified at the genus or species level. The most prevalent genera were Hyalomma (46.99%) and Ixodes (28.49%), followed by Rhipicephalus and Haemaphysalis. Notably, immature forms of Hyalomma spp., particularly nymphs, accounted for the highest proportion of bites (22.65%). The findings highlight Hyalomma and Ixodes as primary vectors for major diseases in Türkiye, with H. marginatum playing a central role in seasonal outbreaks of CCHF in rural Anatolia and Ixodes spp. linked to Lyme disease. Türkiye's geographic and climatic diversity, along with factors such as migratory bird routes, facilitates the distribution of ticks and the emergence of novel tick-borne diseases. Despite the notable risks, inconsistent tick identification and reporting impede accurate assessment and management. Standardized methodologies and comprehensive reporting systems are strongly recommended to better address the public health risks posed by tick-borne diseases.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013092"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12176299/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of scabies and bacterial skin infection in French Polynesia: A cross-sectional community survey.","authors":"Georgia R Walker, Susanna J Lake, Matthew G Parnaby, Tereva Reneteaud, Mihiau Mapotoeke, Romain P Marmorat, Raihei H White, Sarah Andersson, John M Kaldor, Jean-Marc Segalin, Henri-Pierre Mallet, Andrew C Steer, Andre L Wattiaux","doi":"10.1371/journal.pntd.0013119","DOIUrl":"10.1371/journal.pntd.0013119","url":null,"abstract":"<p><strong>Introduction: </strong>The prevalence of scabies and impetigo is high in several Pacific Island countries and has led to the implementation of mass drug administration control strategies. Anecdotal clinical reports have suggested similarly high burdens of scabies and bacterial skin infection in French Polynesia, but formal prevalence data have been lacking. We aimed to determine the prevalence of scabies and bacterial skin infection in French Polynesia's two most populated islands: Tahiti and Mo'orea.</p><p><strong>Methods: </strong>We conducted a community-based cross-sectional survey. Our study was pragmatically restricted to the main islands of Tahiti and Mo'orea, where we selected households using two-stage randomisation from 20 first-stage neighbourhoods. All individuals present in the home were invited to participate. Four nurses and one doctor conducted skin examinations using validated simplified diagnostic criteria to diagnose scabies, informed by the International Alliance for the Control of Scabies 2020 diagnostic criteria.</p><p><strong>Results: </strong>Among 1770 participants, scabies prevalence was 11.9% and was highest among children aged <5 years (31.8%, RR 5.7, 95% CI 3.8 - 8.6, compared to ≥55 years). The overall bacterial skin infection prevalence was 5.5%. Participants with scabies had a 10-fold higher risk of bacterial skin infection compared to those without (26.8% vs 2.7%, RR 10.2, 95% CI 7.5-13.8). Written consent was obtained for all 1770 participants.</p><p><strong>Conclusions: </strong>The prevalence of scabies in this study exceeds 10%, the threshold above which evidence-based public health strategies including mass drug administration (treatment of the entire community, regardless of whether they show evidence of the disease) may be considered.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013119"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173380/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatio-temporal dynamics of hand, foot and mouth disease in Malaysia, 2009-2019.","authors":"Victoria M Cox, Rohani Jahis, Rehan Shuhada Abu Bakar, Noriah Mohd Yusof, Kiroshika Pillay Veel Pilay, Yu Kie Chem, S Selvanesan, Norita Shamsudin, Wes Hinsley, Isobel M Blake, Nor Zahrin Hasran, Norhayati Rusli, I-Ching Sam, Yoke Fun Chan, Margarita Pons-Salort","doi":"10.1371/journal.pntd.0013174","DOIUrl":"10.1371/journal.pntd.0013174","url":null,"abstract":"<p><p>Hand, foot and mouth disease (HFMD) is endemic in Asia-Pacific. There is geographic variability in the timing of HFMD outbreaks throughout the year across the region, and seasonality becomes less clear towards tropical regions. We used syndromic HFMD case surveillance data from 2009 to 2019 (N = 354,769 cases) to characterise the spatio-temporal dynamics of HFMD in Malaysia, which has a tropical climate, and identify factors associated with transmission. Despite the absence of regular annual seasonal patterns of incidence, HFMD epidemics were highly synchronised across districts within Peninsular and East Malaysia, but less so between the two regions. Median estimates of the state-level daily effective reproduction number (Rt) ranged from 0.47 to 1.54. Meteorological factors were found to have a small effect on HFMD transmission compared to the depletion of susceptibles (as a proxy for population immunity) and school closures, likely due to the low seasonal weather variability across the year. Studies using wider spatial scales covering a diversity of climate regions are needed to identify meteorological factors determining the timing of HFMD epidemics across Asia-Pacific countries.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013174"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12180618/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144259157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico identification of Leishmania GP63 protein epitopes to generate a new vaccine antigen against leishmaniasis.","authors":"Mervenur Güvendi, Hüseyin Can, İrem Yavuz, Ahmet Özbilgin, Aysu Değirmenci Döşkaya, Muhammet Karakavuk, Cemal Ün, Adnan Yüksel Gürüz, İsmail Cem Yılmaz, Mayda Gürsel, İhsan Gürsel, Mert Döşkaya","doi":"10.1371/journal.pntd.0013137","DOIUrl":"10.1371/journal.pntd.0013137","url":null,"abstract":"<p><strong>Background: </strong>The surface of Leishmania spp. presents glycoprotein 63 (GP63), a metalloprotease that acts as one of the parasite's major antigens. A vaccine against leishmaniasis has not yet been developed and stationary phase promastigotes have utmost importance in transmitting Leishmania spp. from phlebotomine sand fly to humans or reservoirs. Therefore, this study aimed to analyze GP63 protein in three different Leishmania spp. to determine new vaccine candidate antigen against leishmaniasis using sequencing data of locally detected Leishmania strains and in silico approaches.</p><p><strong>Methodology/principal findings: </strong>The GP63 protein sequences of the stationary phase/amastigote form of L. infantum, L. major, and L. tropica were identified and then the gene encoding GP63 protein in Leishmania positive samples (n:59) was amplified and sequenced for variation analysis. According to the results, 4, 6, 19 GP63 variants were found within L. infantum, L. major, and L. tropica isolates, respectively. The most prevalent variants within each species were selected for further analysis using in silico approaches. Accordingly, all selected GP63 proteins were antigenic and the amount of B and T cell epitopes were 23 for L. infantum, 10 for L. major, and 9 for L. tropica. The analysis of each epitope showed that all of them were non-toxic, non-allergen, and soluble but had different antigenicity values. Among these epitopes, EMEDQGSAGSAGS associated with L. major, STHDSGSTTC and AEDILTDEKRDILRK epitopes associated with L. infantum had the highest antigenicity values for B cell, MHC-I, and MHC-II epitopes, respectively. Moreover, conserved epitopes were detected among two or three Leishmania species.</p><p><strong>Conclusions/significance: </strong>This study detected many epitopes that could be used in vaccine studies and the development of serological diagnostic assays.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013137"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12140206/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144235614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of TaqMan-based quantitative PCR diagnosis for Entamoeba histolytica using droplet digital PCR.","authors":"Akira Kawashima, Yasuaki Yanagawa, Takayuki Chikata, Rieko Shimogawara, Daisuke Mizushima, Kiyoto Tsuchiya, Kenji Yagita, Hiroyuki Gatanaga, Koji Watanabe","doi":"10.1371/journal.pntd.0012935","DOIUrl":"10.1371/journal.pntd.0012935","url":null,"abstract":"<p><strong>Background: </strong>TaqMan-probed quantitative PCR (qPCR) is highly valued for diagnosing Entamoeba histolytica infections (amebiasis). However, unclear cycle threshold (Ct) values often yield low-titer positive results, complicating interpretation. This study aimed to optimize qPCR primer-probe sets with logically determined cut-off Ct value using droplet digital PCR (ddPCR).</p><p><strong>Methodology/principal findings: </strong>Amplification efficacy was evaluated using ddPCR by measuring absolute positive droplet counts (APD) and mean fluorescence intensity at different PCR cycles and annealing temperatures (AT). A primer-probe specific cut-off Ct value was determined from a standard curve by correlating Ct values with APD. Twenty primer-probe sets targeting small subunit rRNA gene regions (X64142) were designed from previous papers. Amplification efficacy remained consistent at high PCR cycles (50 cycles), but differed at lower PCR cycles (30 cycles), identifying five sets with higher amplification efficiency than other candidates. Of these, only two sets maintained efficiency at higher AT (62°C). Ct value was inversely proportional to the square of APD, defining the specific cut-off Ct value as 36 cycles. Selected primer-probe set with a cut-off effectively differentiated E. histolytica infection in clinical specimens. However, discordant results between Ct value and APD were seen in some cases with high Ct value. Shotgun metagenomic sequencing suggested microbial-independent false positive reactions contributed to these discrepancies, although specific reactants were unidentified.</p><p><strong>Conclusions/significance: </strong>The combination use of ddPCR with qPCR revealed that false positive reactions of qPCR and/or ddPCR commonly happen in stool specimens. Also, this study emphasizes the value of ddPCR for establishing accurate cut-off values with efficient primer-probes.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0012935"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12165414/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144235615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smelly communication between haemaphysalis longicornis and infected hosts with indolic odorants: A case from severe fever with thrombocytopenia syndrome virus.","authors":"Zhitong Liu, Hao Feng, Xiaohe Liu, Bin Wu, Hong Zhang, Yi Sun, Jiahong Wu, Chunxiao Li, Jiafu Jiang","doi":"10.1371/journal.pntd.0013139","DOIUrl":"10.1371/journal.pntd.0013139","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objects: &lt;/strong&gt;Vector ticks' perception of characteristic odors emitted by infected hosts is key to understand tick's foraging behavior for infected host and design odor-based control strategies for tick-borne diseases.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Laboratory mice knocked out for type I interferon (IFN) receptors (Ifnar-/-) were used to develop a simulated host by intraperitoneal infection with Bandavirus dabieense (SFTSV). Urine and fecal samples were collected 4 days post-infection and analyzed to detect differential volatile metabolites (DVMs) during infection. Next, the two salient odor cues among the SFTSV-induced host DVMs, indole and 3-methylindole, were used to test the olfactory response of Haemaphysalis. longicornis by electroantennographic detection (EAD) and Y-tube olfactometry, respectively. To gain insight into the potential olfactory mechanism, two olfactory-associated proteins, Niemann-Pick type C2 (NPC2) and Odor Binding Protein-like (OBPL) proteins were annotated from the transcriptomic data derived from H. longicornis forelegs. Online tools were used to predict the ligand binding properties of the two proteins to the two indole candidates. Simultaneously, quantitative RT-PCR using β-actin as an internal reference gene was used to monitor the relative transcript levels of NPC2 and OBPL proteins under the stimulation of two indole candidates. The significantly regulated proteins were cloned and expressed with the vector plasmid pET-28b in vitro. The purified proteins were tested for the binding properties to the two indole candidates.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;SFTSV-infected Ifnar-/- mice upregulated 11 DVMs in fecal samples, mostly indoles and phenols, along with indole biosynthesis and related metabolic processes. In the urine samples, 29 DVMs were downregulated in the infected host, with eucalyptol and phenylalanine acid being the most altered. We test the olfactory responses of H. longicornis to indole and 3-methylindole, which influence tick foraging behavior. The olfactometers showed that the tick preferred both indole and 3-methylindole. EAD tests showed that stimulation of the olfactory receptor neuron in Haller's organ produced significant active potential in response to indoles. Two olfactory proteins, NPC2 and OBPL, were successfully annotated from H. longicornis foreleg transcriptomic data. NPC2 has a β-barrel structure that binds signal chemicals, while OBPL is a classical OBP with a hydrophobic binding cavity. When monitoring the transcript levels of NPC2 and OBPL in the tick forelegs, the increased transcript level (1.2-1.4 folds change) of OBPL was observed following indoles stimulation, compared to the downregulated level (0.6-0.8 folds change) of NPC2 under the same circumstances. The OBPL and NPC2 gene from H. longicornis were successfully cloned and expressed as inclusion proteins respectively. The purified OBPL (20.28 kDa) showed higher affinity for both indole (Ki 2.256μM) and 3-methyl","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013139"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173412/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144235617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of tungiasis prevalence, intensity, and morbidity during a two-year long community-based tungiasis control project in a hyperendemic region in Karamoja, Uganda.","authors":"Hannah McNeilly, Francis Mutebi, Felix Reichert, Marlene Thielecke, Mike L Banalyaki, George M Mukone, Rebecca Arono, Hermann Feldmeier","doi":"10.1371/journal.pntd.0013149","DOIUrl":"10.1371/journal.pntd.0013149","url":null,"abstract":"<p><p>Tungiasis is a widespread and debilitating zoonotic Neglected Tropical Disease (NTD). Manual extraction of the sand fleas with non-sterile sharp instruments is the most common but unsafe treatment method in affected communities. Topical application of a dimeticone oil formula (NYDA) has previously been shown to be a safe and effective method of killing embedded sand fleas. The objective of this study was to evaluate a two-year long humanitarian One Health tungiasis control project in 17 villages in Napak district, Karamoja region, Northeastern Uganda. The community-based intervention included quarterly systematic tungiasis detection and treatment with the dimeticone oil formula in residents and domestic animals in combination with community health promotion. In each of the eight quarterly tungiasis diagnosis and treatment rounds, between 3,674 and 5,155 residents were examined (coverage 73.6-89.9%). Overall, 12,540 tungiasis cases among residents were diagnosed and treated and 16 community dialogue meetings were held. Tungiasis prevalence among residents decreased from 62.8% to 5.7% in the two-year study period. While at baseline tungiasis was most prevalent in children and the elderly, at the end elderly women were the single most affected group. The prevalence of tungiasis-related walking difficulties in the community decreased from 11.5% to 0.5%, and pain and itching were greatly reduced. The number of animals present in the villages was low (between 79 and 414 per treatment round) and the prevalence of tungiasis in animals dropped from 14.2% to 0% throughout the two-year project. This implementation study shows that regular community-based treatment of tungiasis cases among humans and animals with dimeticone oil formula, combined with community engagement and health promotion, can reduce tungiasis prevalence and morbidity to very low levels within two years, even in a hyperendemic area where people live in extreme poverty.</p>","PeriodicalId":49000,"journal":{"name":"PLoS Neglected Tropical Diseases","volume":"19 6","pages":"e0013149"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173417/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144235616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}