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BackgroundCutaneous and mucocutaneous leishmaniasis (CL/ML) cause significant morbidity globally and are vulnerable to changes from environmental events and conflict. In this ecological study, we aim to measure the associations between annual CL/ML cases, conflict intensity, and environmental factors between 2005 and 2022 globally.MethodsWe pulled annual case data from the WHO for 52 nations that had conflict intensity scores (ranging from 1-10) from the Bertelsmann Transformation Index. Using Earth observation tools, we gathered temperature, precipitation, vegetation, and humidity data, in addition to data on annual estimates of population, internal displacement, and GDP. We fit a negative binomial generalized additive model with a random nation-level intercept.ResultsConflict was positively associated with increased CL/ML across the studied nations (IRR: 1.09, 95% CI: 1.01-1.16, p = 0.02). Given this, intense conflict (a score of ten) was associated with over double the risk of CL/ML compared to the lowest conflict levels (score of one). We also identified a curvilinear relationship between mean temperature and cases, as well as between vegetation level and cases. Each had small pockets of significant increased and decreased risk, respectively. Larger mean humidity ranges were negatively associated with cases. Importantly, the relationship between conflict intensity and cases was mediated by displacement.DiscussionConflict is significantly associated with increased CL/ML cases. This is especially true at higher conflict levels, marking when conflict turns violent. The destruction of critical infrastructure (e.g., that related to healthcare, water, and sanitation) often seen during conflict could drive this association. Such environments can be hospitable to sandflies and can heighten individuals' vulnerability through increased malnutrition, poverty, and displacement. Understanding this relationship is crucial for public health preparedness and response, especially as conflicts become increasingly violent and protracted.

Infectious keratitis is a leading cause of corneal blindness worldwide with little information known about causative etiologies in Malawi, Africa. This area is resource-limited with ophthalmologist and microbiology services. The Department of Ophthalmology at the Kamuzu College of Health Sciences in Blantyre, Malawi, is a participating site of an international corneal ulcer consortium, capriCORN (Comprehensive Analysis of Pathogens, Resistomes, and Inflammatory-markers in the CORNea). In this study, 50 patients with corneal ulcers were swabbed for pathogen identification using RNA-sequencing. Corneal trauma was reported in 41% and 19% of the patients worked in agriculture. A pathogen was identified in 58% of the cases. Fungal pathogens predominated, followed by viruses and bacteria. Aspergillus, Fusarium, HSV-1, and Gardnerella were the most common pathogens detected. 50% of patients reported treatment with an antibiotic before presentation. Pathogens unusual for infectious keratitis, such as Subramaniula asteroids, Aureobasidium pullulans, and Gardnerella vaginalis, were also detected.

ObjectiveTo test the effect of proactive home visits by trained community health workers (CHWs) on child survival.MethodsWe conducted a two arm, parallel, unmasked cluster-randomized trial in 137 village-clusters in rural Mali. From February 2017 to January 2020, 31 761 children enrolled at the trial start or at birth. Village-clusters received either primary care services by CHWs providing regular home visits (intervention) or by CHWs providing care at a fixed site (control). In both arms, user fees were removed and primary health centres received staffing and infrastructure improvements before trial start. Using lifetime birth histories from women aged 15-49 years surveyed annually, we estimated incidence rate ratios (IRR) for intention-to-treat and per-protocol effects on under-five mortality using Poisson regression models.FindingsOver three years, we observed 52 970 person-years (27 332 in intervention arm; 25 638 in control arm). During the trial, 909 children in the intervention arm and 827 children in the control arm died. The under-five mortality rate declined from 142.8 (95% CI: 133.3-152.9) to 56.7 (95% CI: 48.5-66.4) deaths per 1000 live births in the intervention arm; and from 154.3 (95% CI: 144.3-164.9) to 54.9 (95% CI: 45.2-64.5) deaths per 1000 live births in the control arm. Intention-to-treat (IRR: 1.02; 95% CI: 0.88-1.19) and per-protocol estimates (IRR: 1.01; 95% CI: 0.87-1.18) showed no difference between study arms.ConclusionThough proactive home visits did not reduce under-five mortality, system-strengthening measures may have contributed to the decline in under-five mortality in both arms.

Scrub typhus, a vector-borne bacterial infection, is an important but neglected disease globally. Accurately characterizing the burden is challenging because of nonspecific symptoms and limited diagnostics. Prior seroepidemiology studies have struggled to find consensus cutoffs that permit comparisons of estimates across contexts and time. In this study, we present a novel approach that does not require a cutoff and instead uses information about antibody kinetics after infection to estimate seroincidence. We use data from three cohorts of scrub typhus patients in Chiang Rai, Thailand, and Vellore, India, to characterize antibody kinetics after infection and two population serosurveys in the Kathmandu Valley, Nepal, and Tamil Nadu, India, to estimate seroincidence. The samples were tested for IgM and IgG responses to Orientia tsutsugamushi-derived recombinant 56-kDa antigen using commercial enzyme-linked immunosorbent assay kits. We used Bayesian hierarchical models to characterize antibody responses after scrub typhus infection and used the joint distributions of the peak antibody titers and decay rates to estimate population-level incidence rates in the cross-sectional serosurveys. Median responses persisted above an optical density (OD) of 1.8 for 23.6 months for IgG and an OD of 1 for 4.5 months for IgM. Among 18- to 29-year-olds, the seroincidence was 10 per 1,000 person-years (95% CI, 5-19) in Tamil Nadu, India, and 14 per 1,000 person-years (95% CI: 10-20) in the Kathmandu Valley, Nepal. When seroincidence was calculated with antibody decay ignored, the disease burden was underestimated by more than 50%. The approach can be deployed prospectively, coupled with existing serosurveys, or leverage banked samples to efficiently generate scrub typhus seroincidence estimates.

BackgroundHepatitis-E virus (HEV), an etiologic agent of acute inflammatory liver disease, is a significant cause of morbidity and mortality in South Asia. HEV is considered endemic in Nepal; but data on population-level infection transmission is sparse.MethodsWe conducted a longitudinal serosurvey in central Nepal to assess HEV exposure. At each visit, capillary blood samples were collected and analyzed for the presence of anti-HEV IgG antibodies. The study took place between February 2019 and April 2021, with up to 4 visits per participant approximately 6 months apart.ResultsWe collected 2513 samples from 923 participants aged 0-25 years, finding a seroprevalence of 4.8% and a seroincidence rate of 10.9 per 1000 person-years. Young adults and individuals consuming surface water faced the highest incidence of infection. Geospatial analysis identified potential HEV clusters, suggesting a need for targeted interventions.SignificanceOur findings demonstrate that HEV is endemic in Nepal and that the risk of infection increases with age.

Engagement is an important component in the advancement of gene-drive vector control research programs as developers look to transition the technology from the laboratory to the field. As research advances and engagement surrounding this novel technology is put into practice, knowledge can be gained from practical experiences and applications in the field. A relationship-based model (RBM) provides a framework for end-user development of engagement programs and strategies. The model places end users at the center of the engagement decision-making processes rather than as recipients of predetermined strategies, methods, and definitions. Successful RBM application for healthcare delivery has previously been demonstrated, and the University of California Malaria Initiative (UCMI) has applied this model to its gene-drive program in the Democratic Republic of São Tomé and Príncipe. The model emphasizes the importance of local leadership in the planning, development, and implementation of all phases of project engagement. The primary aim of this paper is to translate the model from paper to practice and provide a transparent description, using practical examples, of the UCMI program implementation of RBM at its field site. End-user development of the UCMI engagement program provides a unique approach to the development of ethical, transparent, and effective engagement strategies for malaria control programs. This paper may also serve as a reference and example for projects looking to establish an engagement program model that integrates end-user groups in the decision-making processes surrounding engagement.

Over the past decade, considerable progress has been made in the control, elimination, and eradication of neglected tropical diseases (NTDs). Despite these advances, most NTD programs have recently experienced important setbacks; for example, NTD interventions were some of the most frequently and severely impacted by service disruptions due to the coronavirus disease 2019 (COVID-19) pandemic. Mathematical modeling can help inform selection of interventions to meet the targets set out in the NTD road map 2021-2030, and such studies should prioritize questions that are relevant for decision-makers, especially those designing, implementing, and evaluating national and subnational programs. In September 2022, the World Health Organization hosted a stakeholder meeting to identify such priority modeling questions across a range of NTDs and to consider how modeling could inform local decision making. Here, we summarize the outputs of the meeting, highlight common themes in the questions being asked, and discuss how quantitative modeling can support programmatic decisions that may accelerate progress towards the 2030 targets.

Case Presentation: A 21-year-old, otherwise healthy female presented to the emergency department with fever among other nonspecific symptoms after recently returning from Ghana. On physical exam, she had a characteristic upper extremity rash, and a tourniquet test revealed numerous petechiae. The diagnosis of dengue was suspected and subsequently confirmed.Discussion: Dengue is one of many viral illnesses that should be considered in returning travelers presenting with fever and other nonspecific symptoms. Emergency physicians must keep a broad differential when evaluating fever in returned travelers and prioritize history and physical exam findings to help narrow the diagnosis and provide appropriate management and supportive care while awaiting further confirmatory testing.

The field of veterinary entomology is dominated by research concerning insects and arthropods that negatively impact the health of domestic animals. A curated selection of peer-reviewed research which was highlighted at the 2022 Joint Meeting between the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia, which prioritized exploring entomology through the lens of art, science, and culture are summarized. Articles are categorized into (i) biting and non-biting flies, (ii) ectoparasites, and (iii) review articles, with the overall goal of showcasing innovative methodologies, addressing overlooked questions in veterinary entomology, and highlighting comprehensive reviews. While not exhaustive, the selected studies represent a myriad of arthropods, methodologies, and perspectives, to inspire future scientists with diverse research avenues and emphasize the continual evolution and importance of entomological studies in today's world.

A substantial proportion of global travel occurs between low- and middle-income countries (LMICs) for the purposes of migration, medical tourism, trade and employment, and this is likely to accelerate due to climate-change-related migration. Traveller studies based in LMICs are needed to better monitor the global spread of antibiotic resistance.

Sustainable reductions in African malaria transmission require innovative tools for mosquito control. One proposal involves the use of low-threshold gene drive in Anopheles vector species, where a 'causal pathway' would be initiated by (i) the release of a gene drive system in target mosquito vector species, leading to (ii) its transmission to subsequent generations, (iii) its increase in frequency and spread in target mosquito populations, (iv) its simultaneous propagation of a linked genetic trait aimed at reducing vectorial capacity for Plasmodium, and (v) reduced vectorial capacity for parasites in target mosquito populations as the gene drive system reaches fixation in target mosquito populations, causing (vi) decreased malaria incidence and prevalence. Here the scope, objectives, trial design elements, and approaches to monitoring for initial field releases of such gene dive systems are considered, informed by the successful implementation of field trials of biological control agents, as well as other vector control tools, including insecticides, Wolbachia, larvicides, and attractive-toxic sugar bait systems. Specific research questions to be addressed in initial gene drive field trials are identified, and adaptive trial design is explored as a potentially constructive and flexible approach to facilitate testing of the causal pathway. A fundamental question for decision-makers for the first field trials will be whether there should be a selective focus on earlier points of the pathway, such as genetic efficacy via measurement of the increase in frequency and spread of the gene drive system in target populations, or on wider interrogation of the entire pathway including entomological and epidemiological efficacy. How and when epidemiological efficacy will eventually be assessed will be an essential consideration before decisions on any field trial protocols are finalized and implemented, regardless of whether initial field trials focus exclusively on the measurement of genetic efficacy, or on broader aspects of the causal pathway. Statistical and modelling tools are currently under active development and will inform such decisions on initial trial design, locations, and endpoints. Collectively, the considerations here advance the realization of developer ambitions for the first field trials of low-threshold gene drive for malaria vector control within the next 5 years.

BackgroundUnderstanding the clustering of infections for persistent malaria transmission is critical to determining how and where to target specific interventions. This study aimed to determine the density, blood meal sources and malaria transmission risk of anopheline vectors by targeting malaria index cases, their neighboring households and control villages in Arjo-Didessa, southwestern Ethiopia.MethodsAn entomological study was conducted concurrently with a reactive case detection (RCD) study from November 2019 to October 2021 in Arjo Didessa and the surrounding vicinity, southwestern Ethiopia. Anopheline mosquitoes were collected indoors and outdoors in index case households and their surrounding households (neighboring households), as well as in control households, using pyrethrum spray cache (PSC) and U.S. Centers for Disease Control and Prevention (CDC) light traps. Adult mosquitoes were morphologically identified, and speciation in the Anopheles gambiae complex was done by PCR. Mosquito Plasmodium infections and host blood meal sources were detected by circumsporozoite protein enzyme-linked immunosorbent assay (CSP-ELISA) and cytochrome b-based blood meal PCR, respectively.ResultsAmong the 770 anopheline mosquitoes collected, An. gambiae sensu lato (A. gambiae s.l.) was the predominant species, accounting for 87.1% (n = 671/770) of the catch, followed by the Anopheles coustani complex and Anopheles pharoensis, which accounted for 12.6% (n = 97/770) and 0.26% (n = 2/770) of the catch, respectively. From the sub-samples of An. gambiae s.l.analyzed with PCR, An. arabiensis and Anopheles amharicus were identified. The overall mean density of mosquitoes was 1.26 mosquitoes per trap per night using the CDC light traps. Outdoor mosquito density was significantly higher than indoor mosquito density in the index and neighboring households (P = 0.0001). The human blood index (HBI) and bovine blood index (BBI) of An. arabiensis were 20.8% (n = 34/168) and 24.0% (n = 41/168), respectively. The overall Plasmodium sporozoite infection rate of anophelines (An. arabiensis and An. coustani complex) was 4.4% (n = 34/770). Sporozoites were detected indoors and outdoors in captured anopheline mosquitoes. Of these CSP-positive species for Pv-210, Pv-247 and Pf, 41.1% (n = 14/34) were captured outdoors. A significantly higher proportion of sporozoite-infected mosquitoes were caught in index case households (5.6%, n = 8/141) compared to control households (1.1%, n = 2/181) (P = 0.02), and in neighboring households (5.3%, n = 24/448) compared to control households (P = 0.01).ConclusionsThe findings of this study indicated that malaria index cases and their neighboring households had higher outdoor mosquito densities and Plasmodium infection rates. The study also highlighted a relatively higher outdoor mosquito density, which could increase the potential risk of outdoor malaria transmission and may play a role in residual malaria transmission. Thus, it is important to strengthen the implementation of vector control interventions, such as targeted indoor residual spraying, long-lasting insecticidal nets and other supplementary vector control measures such as larval source management and community engagement approaches. Furthermore, in low transmission settings, such as the Arjo Didessa Sugarcane Plantation, providing health education to local communities, enhanced environmental management and entomological surveillance, along with case detection and management by targeting of malaria index cases and their immediate neighboring households, could be important measures to control residual malaria transmission and achieve the targeted elimination goals.

Onchocerciasis (river blindness) is a debilitating tropical disease that causes significant eye and skin damage, afflicting millions worldwide. As global efforts shift from disease management to elimination, vaccines have become crucial supplementary tools. The Onchocerciasis Vaccine for Africa (TOVA) Initiative was established in 2015, to advance at least one vaccine candidate initially targeting onchocerciasis in infants and children below 5 years of age, through Phase I human trials by 2025. Notably, Ov-RAL-2 and Ov-103 antigens have shown great promise during pre-clinical development, however, the overall success rate of vaccine candidates during clinical development remains relatively low due to certain adverse effects and immunogenic limitations. This study, thus, aimed at predicting the safety and immunogenicity of Ov-RAL-2 and Ov-103 potential onchocerciasis vaccine candidates prior to clinical trials. Advanced molecular simulation models and analytical immunoinformatics algorithms were applied to predict potential adverse side effects and efficacy of these antigens in humans. The analyses revealed that both Ov-RAL-2 and Ov-103 demonstrate favourable safety profiles as toxicogenic and allergenic epitopes were found to be absent within each antigen. Also, both antigens were predicted to harbour substantial numbers of a wide range of distinct epitopes (antibodies, cytokines, and T- Cell epitopes) associated with protective immunity against onchocerciasis. In agreement, virtual vaccination simulation forecasted heightened, but sustained levels of primary and secondary protective immune responses to both vaccine candidates over time. Ov-103 was predicted to be non-camouflageable, as it lacked epitopes identical to protein sequences in the human proteome. Indeed, both antigens were able to bind with high affinity and activate the innate immune TLR4 receptor, implying efficient immune recognition. These findings suggest that Ov-RAL-2 and Ov-103 can induce sufficient protective responses through diverse humoral and cellular mechanisms. Overall, our study provides additional layer of evidence for advancing the clinical development of both vaccine candidates against onchocerciasis. [ABSTRACT FROM AUTHOR]

Background: Dengue is the most re-emergent infection, with approximately 100 million new cases reported annually, yet no effective treatment or vaccine exists. Here, we aim to define the microbial community structure and their functional profiles in the dengue positive patients with varying disease severity. Methodology/Principal findings: Hospital admitted 112 dengue-positive patients blood samples were analyzed by dual RNA-sequencing to simultaneously identify the transcriptionally active microbes (TAMs), their expressed genes and associated pathways. Results highlight that patients with severe dengue exhibited increased microbial diversity and presence of opportunistic species (unique and core) which includes Bacillus cereus, Burkholderia pseudomallei, Streptococcus suis, and Serratia marcescens. The functional profile analysis revealed enriched metabolic pathways such as protein degradation, nucleotide biosynthesis, ion transport, cell shape integrity, and ATP formation in severe cases, indicating the high energy demands and adaptability of these microbes. Conclusion: Our metatranscriptomic approach provides a species-level characterization of blood microbiome composition and reveals a heightened diversity of TAMs in patients with severe dengue, underscoring the need for further research into the role of blood microbiota in disease progression. Comparing the microbial signatures across the severity classes early in the disease offers unique potential for convenient and early diagnosis of dengue infection. Author summary: Dengue poses a significant public health challenge in tropical and subtropical regions. The lack of a specific treatment or broadly effective vaccine highlights the critical need for novel approaches. In this study, we investigated the transcriptionally active microbial species (TAMs) in 112 dengue-positive patients from MAX Hospital in Delhi, India, to identify their correlations with disease severity. RNA-seq analysis revealed an increased abundance of opportunistic TAMs in severe dengue patients, with some species showing significant associations with platelet counts and total leukocyte count (TLC). Our findings underscore the underappreciated importance of the blood microbiome in dengue, particularly the heightened metabolic activity of these opportunistic species in severe cases. This study offers valuable insights for early infection diagnosis for dengue management. The species-level data identified here could pave the way for systematic exploration of microbial involvement in dengue virus (DENV) infections, potentially serving as an indicator for new adjuvant treatment strategies. [ABSTRACT FROM AUTHOR]

Burkholderia pseudomallei (Bpm) is the causative agent of the disease melioidosis. As a facultative intracellular pathogen, Bpm has a complex lifestyle that culminates in cell-to-cell fusion and multinucleated giant cells (MNGCs) formation. The virulence factor responsible for MNGC formation is the type 6 secretion system (T6SS), a contractile nanomachine. MNGC formation is a cell-to-cell spread strategy that allows the bacteria to avoid the extracellular immune system and our previous data highlighted cell death, apoptosis, and inflammation as pathways significantly impacted by T6SS activity. Thusly, we investigated how the T6SS influences these phenotypes within the macrophage and pulmonary models of infection. Here we report that the T6SS is responsible for exacerbating apoptotic cell death during infection in both macrophages and the lungs of infected mice. We also demonstrate that although the T6SS does not influence differential macrophage polarization, the M2 polarization observed is potentially beneficial for Bpm pathogenesis and replication. Finally, we show that the T6SS contributes to the severity of inflammatory nodule formation in the lungs, which might be potentially connected to the amount of apoptosis that is triggered by the bacteria. Author summary: Burkholderia pseudomallei (Bpm) is an intracellular pathogen and is the etiological agent of melioidosis. This neglected tropical disease results in an estimated 89,000 fatalities a year, however, this number is believed to be severely underreported. The complex intracellular lifestyle and host response to infection is poorly understood, basic cell interactions and responses are critical to defense against infection. Bpm utilizes an array of virulence factors to successfully replicate and disseminate cell-to-cell, one of these is the T6SS which is responsible for MNGC formation and cell-to-cell spread. In this work, we characterized how macrophages respond to infection in the presence or absence of the critical T6SS virulence factor. Macrophages are a primary replicative niche for Bpm but how intracellular replication disrupts macrophages response to infection is poorly understood. By understanding macrophage cell death patterns and polarization, we can dissect responses that are triggered by T6SS activity with the expectation of finding exploitable responses for host directed therapies. [ABSTRACT FROM AUTHOR]

Background Aims The European Union encompasses 30 outermost and overseas countries and territories (OCTs). Despite a recent increasing activity of renal transplantation in these territories, many patients still undergo transplantation in continental Europe, with follow‐up care coordinated between health professionals from both their transplant center and their home region. Each territory has its unique infectious epidemiology which must be known to ensure appropriate care for kidney transplant recipients (KTRs).This paper proposes a pragmatic approach to optimize pre‐transplant check‐up and to provide an overview of the specific epidemiological features of each region. It offers practical algorithms to help practitioners in managing infected KTR living in these territories. This work advocates for increased collaborative research among European OCTs. [ABSTRACT FROM AUTHOR]

Visceral Leishmaniasis (VL) is a deadly, vector-borne, parasitic, neglected tropical disease, particularly prevalent on the Indian subcontinent. Sleeping under the long-lasting insecticide-treated nets (ITNs) was considered an effective VL prevention and control measures, until KalaNet, a large trial in Nepal and India, did not show enough supporting evidence. In this paper, we adapt a biologically accurate, yet relatively simple compartmental ordinary differential equations (ODE) model of VL transmission and explicitly model the use of ITNs and their role in VL prevention and elimination. We also include a game-theoretic analysis in order to determine an optimal use of ITNs from the individuals' perspective. In agreement with the previous more detailed and complex model, we show that the ITNs coverage amongst the susceptible population has to be unrealistically high (over 96%) in order for VL to be eliminated. However, we also show that if the whole population, including symptomatic and asymptomatic VL cases adopt about 90% ITN usage, then VL can be eliminated. Our model also suggests that ITN usage should be accompanied with other interventions such as vector control. [ABSTRACT FROM AUTHOR]

ABSTRACT Filariae are parasitic nematodes of high veterinary and medical importance, responsible for some acute tropical diseases. They are transmitted through the bite of hematophagous vectors such as biting midges and blackflies. Filariae are among the most prevalent vector‐borne parasitoses in Neotropical primates in which severe infections can cause inflammatory reactions and tissue damage. Given the location inside the host (peritoneal cavity, bloodstream, and lymphatics), the detection of filariid nematodes is challenging and is mostly postmortem; hence the scarcity of studies on the prevalence of filariae in wild primate populations. Here, we report the prevalence of filariid infections in free‐ranging populations of Geoffroy's spider (Ateles geoffroyi) and black howler (Alouatta pigra) monkeys across southern Mexico, using a combination of noninvasive sampling and molecular diagnostic techniques. Fecal samples were screened for filariid DNA by qPCR protocols. A total of 88 samples were examined with an overall prevalence of 26%. Filariae were slightly more common in spider monkeys compared to howler monkeys. This study constitutes the first report of the prevalence of infection of filariid nematodes in populations of wild spider monkey across southern Mexico, and the first reporting of filariae in black howler monkeys, as part of a new era of primate parasitology and the diagnostics of parasite infections in light of the everyday more affordable molecular tools. [ABSTRACT FROM AUTHOR]

Background Neglected tropical diseases (NTDs) affect millions of people in Africa, with Uganda bearing a significant burden. The World Health Organization (WHO) set a goal to reduce NTDs and improve access to diagnosis and management by 2030. However, NTDs have not been well integrated into primary healthcare in many countries, including Uganda, due to limited knowledge and resources among health workers. The study aimed to assess the readiness and capacity of primary healthcare centres to diagnose and manage soil-transmitted helminths (STHs) and schistosomiasis. Methods A cross-sectional quantitative study was conducted among 204 health workers in 20 health facilities in four districts bordering Lake Kyoga. In this study we evaluated health workers' knowledge of symptoms, diagnosis and management of STHs and schistosomiasis as well as the availability of resources and training. Results Our findings indicate that health workers have strong knowledge about STHs (86.76%), with lower knowledge levels regarding Schistosoma haematobium (59.72%) and Schistosoma mansoni (71.43%). Regarding resources and training, 95% of health facilities had laboratory services, but the majority lacked diagnostic equipment. Furthermore, only 17% of health workers reported prior training on schistosomiasis and related topics and only 25% had training on surveillance and reporting. Conclusions While health workers in eastern Uganda demonstrated a good knowledge base for some NTDs, there were knowledge gaps and challenges in training on surveillance and reporting mechanisms. Continuously building the capacity of health workers along with investing in diagnostic infrastructure is essential for improved NTD control and ultimately reducing associated morbidity and mortality in the region. [ABSTRACT FROM AUTHOR]

Chagas disease, also known as American trypanosomiasis, is caused by a protozoan blood-borne pathogen called Trypanosoma cruzi. The World Health Organization (WHO) has classified Chagas as one of 21 neglected tropical diseases present in the world and estimates that 6-7 million people are currently infected with Chagas. Congenital transmission of Chagas disease contributes to a significant amount of new infections, especially in endemic areas where 22.5% of new infections are due to congenital transmission. In this paper, we investigate congenital transmission's impact on Chagas disease dynamics through a mathematical model. Specifically, we examine how treating a proportion of infants born to infected individuals impacts the progression and spread of Chagas disease. The influence of newborn therapy on the dynamics of the model is thoroughly investigated, both theoretically and numerically. The results illustrate the importance of treating a high proportion of newborns to reduce the number of infected cases of the disease. The findings show that the therapy given to newborns is necessary but not sufficient to curb the transmission of Chagas disease, and a comprehensive approach that includes vector and vertical transmission control strategies is essential for eradicating Chagas disease. We also observed that if vector transmission can be controlled, then at least 55% of the newborns need to be treated to eliminate the disease. [ABSTRACT FROM AUTHOR]

Recently a number of broad-range stool parasite PCR assays have been developed. However, there is ongoing disagreement regarding their diagnostic performance, as various studies have produced contradictory results. In this study, we compared the diagnostic accuracy of the Seegene Allplex GI-Parasite and Allplex GI-Helminth assays (SA) with the conventional methods used at the travel clinic of the Institute of Tropical Medicine (ITM) including microscopy, antigen testing, and molecular detection in order to provide insights into the strengths and limitations of this diagnostic tool which may be crucial to select the most appropriate diagnostic tools for the suspected pathogen. A total of 97 native stool samples from 95 patients with suspected gastrointestinal illness were analyzed, including 26 from a frozen collection and 71 prospectively collected samples. The diagnostic performance of SA was notably superior to the conventional workflow in detecting Dientamoeba fragilis (sensitivity 100% vs. 47.4%) and Blastocystis hominis (sensitivity 95% vs. 77.5%). SA had a comparable performance with the conventional workflow in detecting pathogenic protozoa (sensitivity 90% vs. 95%). In contrast, SA had a much lower diagnostic performance in detecting helminths (59.1%) compared to the conventional workflow (100%). We conclude that the Seegene Allplex GI-Parasite assay may be useful for protozoa screening in low-endemic industrialized countries. However, the Allplex GI-Helminth assay is not recommended due to its suboptimal performance compared to microscopy. [ABSTRACT FROM AUTHOR]

Mosquitoes transmit viruses that affect public health in tropical regions. Identifying factors that influence their fitness can help control mosquito-borne diseases. We investigated the impacts of predation risk effects, from a fish predator, and food availability on the oviposition behavior of Aedes aegypti. We hypothesize that predation risk and food availability interactively affect Ae. aegypti oviposition. Gravid Ae. aegypti females were offered oviposition sites with all possible combinations of predation risk (with vs. without predator cues) and food availability (low vs. high). We found a significant interaction between predation risk and food availability. The magnitude of oviposition and the probability of egg laying in high food availability treatments exceeded the values of low food availability treatments, but only in treatments without predation risk. Predation risk critically modulated the effects of food availability on the oviposition of Ae. aegypti. This study demonstrates the interplay between predation risk and food availability in controlling mosquito-borne diseases. [ABSTRACT FROM AUTHOR]

Mycetoma is a debilitating neglected tropical disease that affects individuals worldwide, particularly in regions where there is poverty and limited health care access. The Mycetoma Research Center (MRC), based in Khartoum, Sudan, provides a sustainable, holistic approach to patient care as the only World Health Organization collaborating center for mycetoma. We describe MRC activities that align with the United Nations' Sustainable Development Goals to control mycetoma in Sudan and globally. [ABSTRACT FROM AUTHOR]

Background: Out of the 21 neglected tropical diseases (NTDs) listed by the World Health Organization, 15 affect the People's Republic of China. Despite significant achievements in controlling NTDs, comprehensive assessments of the disease burden based on actual case data and detailed information on spatial and temporal dynamics are still lacking. This study aims to assess the disease burden and spatial–temporal distribution of NTDs in China from 2005 to 2020, to provide a reference for the formulation of national health agendas in line with the global health agenda, and guide resource allocation. Methods: The number of cases and deaths of major NTDs in China from 2005 to 2020 were downloaded from the China Public Health Science Data Center (https://www.phsciencedata.cn/Share/index.jsp) of the Chinese Center for Disease Control and Prevention and relevant literatures. Simplified formulas for disability-adjusted life years (DALYs) helped estimate the years of life lost (YLLs), years lived with disability (YLDs), and total DALYs. Spatial autocorrelation analysis of the average NTDs burden data for the years 2005 to 2020 was evaluated using Moran's I statistic. Results: China's overall NTDs burden decreased significantly, from 245,444.53 DALYs in 2005 to 18,984.34 DALYs in 2020, marking a reduction of 92.27%. In 2005, the DALYs caused by schistosomiasis and rabies represent a substantial proportion of the total disease burden, accounting for 65.37% and 34.43% respectively. In 2015, Hunan and Sichuan provinces had the highest diversity of NTDs, with 9 and 8 number of different NTDs reported respectively. And the highest disease burden was observed in Sichuan (242,683.46 DALYs), Xizang Zizhiqu (178,318.99 DALYs) and Guangdong (154,228.31 DALYs). The "high-high" clustering areas of NTDs were mainly in China's central and southern regions, as identified by spatial autocorrelation analysis. Conclusions: China has made unremitting efforts in the prevention and control of NTDs, and the disease burden of major NTDs in China has decreased significantly. Using the One Health concept to guide disease prevention and control in the field to effectively save medical resources and achieve precise intervention. [ABSTRACT FROM AUTHOR]

Born in 1940 in Rasht, Iran, Dr. Farrokh Modabber earned his B.A. in Bacteriology and Ph.D. in Microbiology from University of California, Los Angeles (UCLA). He joined the Harvard Medical School as a fellow before transitioning to a faculty role at Harvard School of Public Health (HSPH) and played a pivotal role in advancing Cellular Immunology. In the early 1970s, he returned to Iran as an Associate Professor at Pahlavi University in Shiraz. Subsequently, he rejoined HSPH before embarking on a tenure at Tehran University. As the head of the Pathobiology Department at Tehran University School of Public Health, he initiated the Tehran/Harvard joint M.Sc. program in Immunology, which played a crucial role in shaping the careers of numerous Iranian immunologists over the following decades. Dr. Modabber went on to hold esteemed positions such as Director General of the Pasteur Institute of Iran, visiting immunology lecturer at various universities, Coordinator of Research Capability Strengthening of WHO's Special Program for Research and Training in Tropical Diseases (TDR), Director of the Infectious Disease Research Institute (IDRI), and Senior Advisor of Drugs for Neglected Diseases initiative (DNDi), to name a few. This article highlights Dr. Modabber's impactful career, focusing on his efforts to combat global leishmaniasis. [ABSTRACT FROM AUTHOR]

Simple Summary: Dengue fever is one of the major public health issues in tropical and subtropical regions. To prevent infection by the Dengue Virus, the World Health Organization has approved two dengue vaccines, Dengvaxia and TV003/TV005. But, unfortunately, the vaccines face challenges such as lower effectiveness and antibody-dependent enhancement (ADE). To address these concerns, we have designed a new vaccine, PSDV-2, with optimized B- and T-cell epitopes using an in silico approach. This design prioritizes high antigenicity and immunogenicity while minimizing risks such as allergenicity, toxicity, and ADE. In simulations, PSDV-2 bound strongly to immune receptors TLRs 4 and 2 and triggered a strong immune response. Although further testing is needed to confirm the effectiveness and safety of PSDV-2, our design offers a promising alternative option for dengue fever prevention, potentially contributing to an improvement in global health. Dengue virus poses a significant global health challenge, particularly in tropical and subtropical regions. Despite the urgent demand for vaccines in the control of the disease, the two approved vaccines, Dengvaxia and TV003/TV005, there are current questions regarding their effectiveness due to an increased risk of antibody-dependent enhancement (ADE) and reduced protection. These challenges have underscored the need for further development of improved vaccines for Dengue Virus. This study presents a new design using an in silico approach to generate a more effective dengue vaccine. Initially, our design process began with the collection of Dengue polyprotein sequences from 10 representative countries worldwide. And then conserved fragments of viral proteins were retrieved as the bases for epitope screening. The selection of epitopes was then carried out with criteria such as antigenicity, immunogenicity, and binding affinity with MHC molecules, while the exclusion criteria were according to their allergenicity, toxicity, and potential for antibody-dependent enhancement. We then constructed a core antigen with the selected epitopes and linked the outcomes with distinct adjuvant proteins, resulting in three candidate vaccines: PSDV-1, PSDV-2, and PSDV-3. Among these, PSDV-2 was selected for further validation due to its superior physicochemical and structural properties. Extensive simulations demonstrated that PSDV-2 exhibited strong binding to pattern recognition receptors, high stability, and robust immune induction, confirming its potential as a high-quality vaccine candidate. For its recombinant expression, a plasmid was subsequently designed. Our new vaccine design offers a promising additional option for Dengue virus protection. Further experimental validations will be conducted to confirm its protective efficacy and safety. [ABSTRACT FROM AUTHOR]

Ophidism is a public health problem in tropical countries, occurring predominantly in rural areas. In Colombia, among the species responsible for snakebite envenomation, inflicting high mortality, is the Chocoan bushmaster, Lachesis acrochorda, better known locally by the names "verrugosa (warty)" and "pudridora (rot-causing)". In this research, the cardiotoxic effect of the venom of L. acrochorda in male Wistar rats weighing 230 ± 20 g was evaluated. A statistical design of randomized blocks was implemented with three treated groups, injected with lyophilized venom (doses of 3.22 μg/g, 6.43 μg/g, 12.86 μg/g), and a control group injected with 0.9% saline solution. Electrocardiographic (ECG) recordings were taken from the anesthetized animals, revealing an increase in the amplitude of the P and T waves and an increase in the duration of the QT intervals in the electrocardiographic recordings. These increases were not observed in the control biomodels. In the analysis of the CK and CK-MB enzyme levels, increases were also observed in the levels of cardiac isoenzymes in the injected animals, but none in the control animals. The histopathological analyses carried out reveal that the injected animals showed effects such as interfibrillar and perivascular edema, cellular shortening of the cardiomyocytes, foci with tissue destructuring, and necrosis with contraction bands. In conclusion, the venom of the Lachesis acrochorda snake increases the P and T waves and the QT interval and increases the CK and CK-MB enzymes in the blood. Additionally, it causes interfibrillar and perivascular edema in the cardiac tissue, cardiocytolysis, and contraction bands. [ABSTRACT FROM AUTHOR]

Background: Strongyloidiasis, a parasitic infection, presents a significant public health challenge in tropical regions due to the limited repertoire of effective treatments. The screening of chemical libraries against the therapeutically relevant third-stage larvae (L3) of the model parasite Strongyloides venezuelensis yielded meager success rates. This situation is reminiscent of Gram-negative bacteria, where drug entry is a limiting factor. Methods: Here, we set out to determine whether similar barriers are in place and establish whether structural and property requirements exist for anti-strongyloides drug discovery. We focused on dyes as their uptake and effects on viability can be independently assessed in the multicellular parasite, thus providing a means to study the possibility of similar entry rules. We tested different dyes in in vitro assays on L3s. Results: We found that staining was necessary to reduce parasite viability, with some dyes achieving anti-strongyloides effects at concentrations similar to those of the reference drug, ivermectin (IV). Some dyes also showed activity against female adults at concentrations well below that of ivermectin. Unfortunately, the most potent dye, Methylene Blue, was unable to prevent the infection in a preliminary in vivo mouse model assay, presumably due to fast dye clearance. Structural analysis showed that positive charges facilitated the access of the compounds to the L3 tissue, thus providing a structural tool for the introduction of activity. For female adults, low globularity is additionally required. As a proof of concept, we added a positive charge to an inactive compound of one of our chemical libraries and re-determined the activity. Conclusions: These findings allow us to establish structural rules for parasite entry that could be of interest for future drug screening or drug development campaigns. These rules might also be applicable to other related parasites. [ABSTRACT FROM AUTHOR]

This article relates how tropical disease ravaged the British army in the late-eighteenth-century Caribbean, using the San Juan expedition of 1780 as a case study. Based on eighteenth-century European understandings of epidemiology, martial and medicinal officials of the San Juan expedition believed that the outbreak of pestilence within the British army reflected a failure in discipline, properly provisioning troops, as well as overall leadership and planning. Thus, despite natural agents playing a significant role in stalling Britain's advance in Nicaragua, eighteenth-century military and medical authorities dictated that difficulties caused by disease and the environment could be overcome by human might. While the British ultimately could not overcome the devastating effects that tropical diseases had on the army, human agency also led to the expedition's failure. The British did not maintain good relations with their Indigenous allies, the Miskito, which resulted in their abandonment of the campaign. Consequently, they were left without crucial soldiers, guides, and labourers who were necessary to continue the invasion of Central America. Moreover, the Spaniards' stout defence of their territory also hindered the British expeditionary force, stalling their advance at the Castillo de la Inmaculada Concepción. As a result, both natural and human agency dictated the outcome of the San Juan expedition. [ABSTRACT FROM AUTHOR]

The genus Naegleria is a taxonomic subfamily consisting of 47 free-living amoebae. The genus can be found in warm aqueous or soil habitats worldwide. The species Naegleria fowleri is probably the best-known species of this genus. As a facultative parasite, the protist is not dependent on hosts to complete its life cycle. However, it can infect humans by entering the nose during water contact, such as swimming, and travel along the olfactory nerve to the brain. There it causes a purulent meningitis (primary amoebic meningoencephalitis or PAME). Symptoms are severe and death usually occurs within the first week. PAME is a frightening infectious disease for which there is neither a proven cure nor a vaccine. In order to contain the disease and give patients any chance to survival, action must be taken quickly. A rapid diagnosis is therefore crucial. PAME is diagnosed by the detection of amoebae in the liquor and later in the cerebrospinal fluid. For this purpose, CSF samples are cultured and stained and finally examined microscopically. Molecular techniques such as PCR or ELISA support the microscopic analysis and secure the diagnosis. [ABSTRACT FROM AUTHOR]

As neglected tropical disease programs rely on participation in rounds of mass drug administration (MDA), there is concern that individuals who have never been treated could contribute to ongoing transmission, posing a barrier to elimination. Previous research has suggested that the size and characteristics of the never-treated population may be important but have not been sufficiently explored. To address this critical knowledge gap, four meetings were held from December 2020 to May 2021 to compile expert knowledge on never treatment in lymphatic filariasis (LF) MDA programs. The meetings explored four questions: the number and proportion of people never treated, their sociodemographic characteristics, their infection status and the reasons why they were not treated. Meeting discussions noted key issues requiring further exploration, including how to standardize measurement of the never treated, adapt and use existing tools to capture never-treated data and ensure representation of never-treated people in data collection. Recognizing that patterns of never treatment are situation specific, participants noted measurement should be quick, inexpensive and focused on local solutions. Furthermore, programs should use existing data to generate mathematical models to understand what levels of never treatment may compromise LF elimination goals or trigger programmatic action. [ABSTRACT FROM AUTHOR]

Objective: Tropical diabetic hand syndrome (TDHS) is rarely described and recognized in the literature as a complication in people with diabetes, and Mexico has high incidence rates of diabetes mellitus II (DMII). The minor or major amputation of the arm represents a physically and economically significant morbidity problem in patients. To optimize the diagnosis and treatment, in this work, we identify prognostic factors and their association with the severity of TDHS and the need for amputation in patients with diabetes mellitus and hand tissue infection. Methods: A total of 55 patients with a confirmed diagnosis of DMII with soft tissue infection in the hand referred to the plastic and reconstructive surgery department were studied for their evaluation and treatment. We analyze sociodemographic and clinical factors and follow-up of remission and recovery in limb functions. Results: In our study, we identified factors associated with amputation such as schooling under 6 years (OR: 21.98, confidence interval (CI): 1.21–3.98, p = 0.003), body mass index ≥ 20 (OR: 0.07, CI = 0.003–1.41, p = 0.031), and history of amputation (no upper limb) (OR: 5.9, CI = 1.11–32.1, p = 0.032). Furthermore, people with TDHS requiring amputation had slightly higher glycated hemoglobin (Hb1Ac) ≥ 10% (OR: 2.36, CI = 0.62–8.98, p = 0.338), and the risk of death was also increased (OR: 3.4, CI = 0.355–32.6, p = 0.288), although these outcomes did not reach statistical significance. Conclusions: Risk factors for amputation as a treatment of THDS are directly linked to lower schooling status, poor nutrition/low weight, as well as previous amputation procedures in patients. These data will help to establish a timelier evaluation and management in patients with suspected THDS. [ABSTRACT FROM AUTHOR]

Vitamin A deficiency and its associated disorders are pervasive in sub‐Saharan Africa (SSA) including many middle‐ and low‐income countries across the world. Provitamin A‐enriched maize (Zea mays L.) inbred lines with desirable agronomic and adaptive traits have been developed and used to generate and commercialize maize varieties with medium to high levels of provitamin A in a few countries to curb vitamin A deficiency. Nonetheless, these inbred lines have not been made widely available to the public and private sector breeders in many countries. The main purpose for releasing the 21 provitamin A‐enriched tropical maize inbred lines (PI 705424–PI 705444, Reg. nos. GP‐624–GP‐644) is to supply maize breeders with elite source germplasm for increasing provitamin A and other carotenoids to much higher levels to offset losses during storage, natural degradation, and processing. These inbred lines were developed at the International Institute of Tropical Agriculture (IITA) from backcrosses of high β‐carotene temperate lines as donors and elite tropical lines as recipients. These inbred lines were developed through repeated self‐pollination with rigorous visual selection among and within lines for plant vigor, synchronous silk emergence and pollen shedding, low ear placement, and resistance to lodging and major tropical diseases, followed by selection for bright yellow to orange kernel color with semi flint to flint kernel texture after harvest. The released maize inbred lines will be diverse sources of favorable alleles to accelerate genetic gain in provitamin A and other beneficial carotenoid enrichment for human health. Core Ideas: Vitamin A deficiency and its associated disorders are pervasive in sub‐Saharan Africa and other developing countries.Provitamin A‐enriched inbred lines are important for developing and commercializing maize varieties to curb Vitamin A deficiencies.Supplying tropical elite inbred lines to breeders will facilitate increasing provitamin A and other beneficial carotenoids to human health.Releasing diverse elite inbred lines promotes access to favorable alleles for further enrichment of beneficial carotenoids. [ABSTRACT FROM AUTHOR]

Colletotrichum spp. is a phytopathogen causing anthracnose in a variety of tropical fruits. Strategies used to control postharvest diseases in tropical fruits typically rely on the use of synthetic fungicides, which have stimulated the emergence of resistant pathogens. Safer alternative strategies to control anthracnose in tropical fruits have been described in the literature. This review presents and discusses the main innovative interventions concerning the application of sustainable alternative strategies in the postharvest control of pathogenic Colletotrichum species in tropical fruits, with a particular emphasis on the studies published in the last 5 years. The available studies have shown the use of various methods, including physical barriers, natural antimicrobials, and biological control with antagonistic microorganisms, to reduce anthracnose lesion severity and incidence in tropical fruits. The available literature showed high inhibitory activity in vitro, reduced anthracnose incidence and lesion diameter, and total disease inhibition in tropical fruits. Most studies focused on the inhibition of Colletotrichum gloeosporioides on avocado, papaya, and mango, as well as of Colletotrichum musae on banana; however, the inhibition of other Colletotrichum species was also demonstrated. The application of emerging sustainable alternative methods, including natural antimicrobial substances, also stimulated the induction of defense systems in tropical fruits, including enzymatic activity, such as polyphenol oxidase, peroxidase, and phenylalanine ammonia‐lyase. The retrieved data helped to understand the current state of the research field and reveal new perspectives on developing efficient and sustainable intervention strategies to control pathogenic Colletotrichum species and anthracnose development in tropical fruits. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the magnetic resonance imaging (MRI) features and classification of echinococcosis of the spinal canal. The clinical manifestations and MRI findings and classification of 19 patients diagnosed with intraspinal echinococcosis over 10 years (2011–2020) were retrospectively analyzed. The mean age of the nine males and 10 females was 39 years (range 28–65 years). Among these, the number of cases with thoracic, lumbar, sacral, thoracolumbar, and lumbosacral, cervical, and lumbar segments was nine (47 %), five (26 %), one (5 %), one (5 %), two (11 %), and one (5 %) cases, respectively. Furthermore, 13 cases (69 %) involved adjacent vertebral bodies, accessories, and surrounding soft tissues. The lesion was confined to the intramedullary, extramedullary subdural, extramedullary epidural, and multiple spaces in one (Type I) (5 %), four (Type II) (21 %), one (Type III) (5 %), and thirteen (69 %) cases, respectively. Moreover, nine cases (47 %) had a history of hydatid disease in the spine or other tissues. The clinical manifestations were chest and lumbosacral pain in 18 cases (95 %) and chest and lumbosacral pain accompanied by lower limb dysfunction in four cases (21 %). The MRI revealed different sizes of T1WI low-signal and T2WI high-signal vesicles with a "grape-like" appearance, with 16 cases (84 %) showing low signals on the edge of the cyst wall. Intraspinal echinococcosis is rare, even in endemic areas. However, intraspinal echinococcosis should be considered when there is a history of echinococcosis in other sites or when there are clear MRI characteristics for the disease. • Echinococcosis is rare in clinical practice, this study selected a more rare location-spinal echinococcosis. • This study provides a new imaging direction for the classification of intraspinal echinococcosis. • This study describes the MRI features of intraspinal echinococcosis. [ABSTRACT FROM AUTHOR]

Among the main arboviruses affecting public health in tropical regions are dengue, zika, and chikungunya, transmitted mainly by mosquitoes of the Aedes genus, especially Aedes aegypti. In recent years, outbreaks have posed major challenges to global health, highlighting the need for integrated and innovative strategies for their control and prevention. Prevention strategies include the elimination of vectors and avoiding mosquito bites; this can be achieved through the use of bioinsecticides and repellents based on plant phytochemicals, as they offer sustainable, ecological, and low-cost alternatives. Mexico has a variety of plants from which both extracts and essential oils have been obtained which have demonstrated significant efficacy in repelling and/or killing insect vectors. This review examines the current knowledge on plant species found in Mexico which are promising options concerning synthetic compounds in terms of their repellent and insecticidal properties against mosquitoes of the genus Aedes and that are friendly to the environment and health. [ABSTRACT FROM AUTHOR]

HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a progressive non-remitting and incapacitating disease more frequently seen in women and with a patchy worldwide distribution. HAM/TSP develops in a small percentage of HTLV-1-infected individuals during their lifetime and etiologic factors for disease progression are still unclear. This study aims to describe the first case series of the progression of HAM/TSP in relation to pregnancy. Between January and March of 2012, we reviewed medical charts of women with HAM/TSP currently enrolled in the HTLV-1 cohort at the institute of tropical medicine of Cayetano Heredia University. Inclusion criteria included having a diagnosis of HAM/TSP according to the WHO guidelines and self-reported initial symptoms of HAM/TSP during pregnancy or within six months of delivery. Fifteen women reported having had symptoms compatible with HAM/TSP within four months of delivery. Among them, ten women had no symptoms before pregnancy and reported gait impairment after delivery. Five women with mild gait impairment before pregnancy noticed a worsening of their symptoms after delivery. Symptoms worsened after successive pregnancies. Recent studies have shown that HTLV-1 infection induces a strong T cell-mediated response and that the quality of this response plays a role in HAM/TSP pathogenesis. The relative immunosuppression during pregnancy, including blunting of the T-cell response, might allowed in certain women enhanced replication of HTLV-1 and disease progression in the postpartum. This is the first study looking specifically at HAM/TSP and pregnancy and the number of cases is remarkable. Further prospective studies of HTLV-1-infected women assessing immune markers during pregnancy are warranted. Breastfeeding was the main route of transmission. Strategies to prevent vertical transmission need to be evaluated in HTLV-1 endemic countries of Latin America. [ABSTRACT FROM AUTHOR]

Burkholderia pseudomallei (Bp) causes the tropical disease melioidosis that afflicts an estimated 165,000 people each year. Bp is a facultative intracellular pathogen that transits through distinct intracellular stages including attachment to host cells, invasion through the endocytic pathway, escape from the endosome, replication in the cytoplasm, generation of protrusions towards neighboring cells, and host cell fusion allowing Bp infection to spread without exiting the intracellular environment. We have identified a TetR-like transcriptional regulator, BP1026B_II1561, that is up-regulated during the late stages of infection as Bp protrudes toward neighboring cells. We have characterized BP1026B_ II1561 and determined that it has a role in pathogenesis. A deletional mutant of BP1026B_II1561 is attenuated in RAW264.7 macrophage and BALB/c mouse models of infection. Using RNA-seq, we found that BP1026B_II1561 controls secondary metabolite biosynthesis, fatty acid degradation, and propanoate metabolism. In addition, we identified that BP1026B_II1561 directly controls expression of an outer membrane porin and genes in the shikimate biosynthetic pathway using ChIP-seq. Transposon mutants of genes within the BP1026B_ II1561 regulon show defects during intracellular replication in RAW264.7 cells confirming the role of this transcriptional regulator and the pathways it controls in pathogenesis. BP1026B_II1561 also up-regulates the majority of the enzymes in shikimate and tryptophan biosynthetic pathways, suggesting their importance for Bp physiology. To investigate this, we tested fluorinated analogs of anthranilate and tryptophan, intermediates and products of the shikimate and tryptophan biosynthetic pathways, respectively, and showed inhibition of Bp growth at nanomolar concentrations. The expression of these pathways by BP1026b_II1561 and during intracellular infection combined with the inhibition of Bp growth by fluorotryptophan/anthranilate highlights these pathways as potential targets for therapeutic intervention against melioidosis. In the present study, we have identified BP1026B_II1561 as a critical transcriptional regulator for Bp pathogenesis and partially characterized its role during host cell infection. [ABSTRACT FROM AUTHOR]

Background: Mosquito-borne diseases, such as malaria, dengue, Zika and chikungunya, pose significant public health threats in tropical and subtropical regions worldwide. To mitigate the impact of these diseases on human health, effective vector surveillance and control strategies are necessary. Traditional vector control methods, which rely on chemical agents such as insecticides and larvicides, face challenges such as resistance and environmental concerns. Consequently, there has been a push to explore novel surveillance and control tools. Mass trapping interventions have emerged as a promising and environmentally friendly approach to reducing the burden of mosquito-borne diseases. This study assessed mass-trapping interventions using autocidal gravid ovitraps (AGOs) on Aedes aegypti populations in Reynosa, Tamaulipas, Mexico. Methods: Four neighborhoods were selected to evaluate the effects of three treatments: AGO mass-trapping, integrated vector control (IVC), which included source reduction and the application of chemical larvicide and adulticide, and AGO + IVC on Ae. aegypti populations. A control area with no interventions was also included. The effectiveness of the interventions was evaluated by comparing Ae. aegypti abundance between the pre-treatment period (9 weeks) and the post-treatment period (11 weeks) for each treatment. Results: Only treatment using AGO mass trapping with an 84% coverage significantly reduced Ae. aegypti female populations by 47%, from 3.75 ± 0.32 to 1.96 ± 0.15 females/trap/week. As expected, the abundance of Ae. aegypti in the control area did not differ from the pre- and post-treatment period (range of 4.97 ± 0.59 to 5.78 ± 0.53); Ae. aegypti abundance in the IVC treatment was 3.47 ± 0.30 before and 4.13 ± 0.35 after, which was not significantly different. However, Ae. aegypti abundance in the AGO + IVC treatment increased from 1.43 ± 0.21 before to 2.11 ± 0.20 after interventions; this increase may be explained in part by the low AGO (56%) coverage. Conclusions: This is the first report to our knowledge on the effectiveness of mass-trapping interventions with AGOs in Mexico, establishing AGOs as a potential tool for controlling Ae. aegypti in Northeastern Mexico when deployed with sufficient coverage. [ABSTRACT FROM AUTHOR]

Background: Extensive attention has been devoted to studies of Trypanosoma lewisi in rodents ever since it became recognised as a zoonotic pathogen known as atypical human trypanosomiasis. Regrettably, although T. lewisi infections of small mammals remain significant public health concerns for humans, there is a lack of comprehensive study in Indonesia. Aim: The aim of the study was to detect T. lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District. Methods: A total of 169 rodents were captured across three villages of Kampung Mandar, Lateng and Kepatihan, using rat single live traps. After being euthanized and identified, the blood samples were collected from each rodent via cardiac puncture. Subsequently, the samples were subjected to native (direct blood microscopic examination), microscopic blood smear examination, and molecular analyses utilizing TRYP1S-TRYP1R (623 bp) and LEW1SLEW1R (220 bp). Results: The results demonstrated that two species of rodents were successfully captured: Rattus norvegicus (65.68%) and Rattus tanezumi (34.32%). Based on the native and microscopic blood smear examinations, the prevalence of T. lewisi across three villages was 23.08% and 24.26% for molecular analysis employing both primers, respectively. The highest prevalence was found in Kampung Mandar Village (31.18%), followed by Kepatihan (16.67%) and Lateng Villages (15.71%). Conclusion: Statistical analysis revealed that T. lewisi was more prevalent in R. tanezumi compared to R. norvegicus. In terms of sex, no statistically significant distinction was observed between female and male infected rodents of either species (p > 0.05), indicating both species can serve as a source of T. lewisi for humans in the surveyed villages. [ABSTRACT FROM AUTHOR]

Background and Aims Elucidating whether prior dengue potentially confers cross-protection against COVID-19 is of public health importance in tropical countries at risk of overlapping dengue and COVID-19 epidemics. However, studies to date have yielded conflicting results. We aimed to assess effects of recent prior dengue infection on risk and severity of subsequent SARS-CoV-2 infection among adult Singaporeans. Methods A retrospective cohort study including all adult Singaporeans aged ≥18 years was conducted from 1 July 2021 through 31 October 2022, when a dengue outbreak driven by the DENV3 serotype preceded subsequent waves of SARS-CoV-2 Delta/Omicron transmission in Singapore. SARS-CoV-2 and dengue infection status were classified using national registries. Cox regression models adjusted for demographics, COVID-19 vaccination status, comorbidity, and socioeconomic-status were used to assess risks and severity (hospitalization, severe illness) of SARS-CoV-2 infection occurring after previous recorded dengue infection. Results A total of 3 366 399 individuals were included, contributing 1 399 696 530 person-days of observation. A total of 13 434 dengue infections and 1 253 520 subsequent SARS-CoV-2 infections were recorded; with an average of 94.7 days (standard deviation = 83.8) between dengue infection and SARS-CoV-2 infection. Preceding dengue infection was associated with a modest increase in risk of subsequent SARS-CoV-2 infection (adjusted hazards ratio [aHR] = 1.13; 95% confidence interval [CI], 1.08–1.17), and significantly elevated risk of subsequent COVID-19 hospitalization (aHR = 3.25; 95% CI, 2.78–3.82) and severe COVID-19 (aHR = 3.39; 95% CI, 2.29–5.03). Conclusions Increased risk of SARS-CoV-2 infection and adverse COVID-19 outcomes were observed following preceding dengue infection in a national population-based cohort of adult Singaporeans. This observation is of significance in tropical countries with overlapping dengue and COVID-19 outbreaks. [ABSTRACT FROM AUTHOR]

Background/Objectives: Royal Darwin Hospital (RDH) is the sole public dermatology service in the Northern Territory (NT). Prescription of biologic therapies (BT) in the NT is uniquely challenging, with remote populations carrying a high tropical disease burden. The aim of this audit is to examine the demographics and outcomes of patients on BT for dermatologic conditions. Methods: Retrospective case note review of patients receiving BT through the RDH Dermatology department between August 2021 and October 2023. Data analysed were demographics, location, dermatological diagnosis and serology status. Results: In this audit, 115 patients were included. Age range of 13–91 years, mean of 51.1 years (±14.7), 52 (45.2%) patients were female and 8 (7.8%) identified as First Nations Australian. A large geographical area was serviced, with a primary address between 1 and 1496 km from RDH. Eighteen patients (15.7%) have discontinued BT completely. There was a statistically significant relationship between cessation of BT and increased distance of primary residence from RDH (p < 0.0007). Eighteen patients (15.7%) required management of infections identified in opportunistic infection screening. These infections were strongyloidiasis, tuberculosis, melioidosis and hepatitis B. Conclusions: There is significant anxiety surrounding BT and tropical infections, including in returning travellers in southern Australian states. There has been particular interest in strongyloidiasis infection, as dupilumab acts on the Th2 immunity mechanism critical to parasitic infection response. This audit exhibits the unique experience of dermatological care in a tropical setting, demonstrating how BT can be used safely and how, when identified, these tropical infections can be successfully managed. [ABSTRACT FROM AUTHOR]

Echinococcosis presents diverse clinical manifestations, including pulmonary hydatidosis, often asymptomatic but complicated by rare yet dramatic occurrences like hydatoptysis. Here, we report a unique case of recurrent pulmonary and abdominal hydatidosis in a 59-year-old female with bronchial fistulization and hydatoptysis, despite previous surgical interventions. Imaging revealed characteristic features aiding in diagnosis and management decisions. The challenges in managing recurrent echinococcosis underscore the importance of comprehensive follow-up and multidisciplinary care. Surgical intervention remains pivotal, supplemented by medical therapy with careful consideration of risks and benefits. This case also presents rare images, absent in much of the literature, which provide valuable insights into the disease's presentation and progression. [ABSTRACT FROM AUTHOR]

Tropical diseases present significant challenges to global health, particularly in resource-limited regions. Early and accurate detection of these diseases is vital for effective management and control. In recent years, metallic-based LSPR sensors have emerged as promising diagnostic tools for sensitive and rapid detection of tropical diseases. This comprehensive review aims to provide an in-depth analysis of the current state of research on metallic-based LSPR sensors for the detection of various tropical diseases. In this study, we focused on the connection between neglected tropical diseases (NTDs) and its risk using metallic-based LSPR sensors to identify potential inflammatory biomarkers. We conducted a literature search using PubMed, Web of Science, and Google Scholar. Only published materials written in English were considered, resulting in the identification of ∼ 220 articles. After a comprehensive evaluation, we selected 35 relevant ones. Our analysis revealed 35 links to neglected tropical diseases, providing valuable insights into their relationship using metallic-based LSPR sensors. Moreover, we explore the potential of metallic-based LSPR sensors in point-of-care testing and their integration with emerging technologies such as microfluidics and smartphone-based diagnostics. This review underscores the need for continued research efforts to develop affordable, sensitive, and user-friendly metallic-based LSPR sensors for early detection and surveillance of tropical diseases. [ABSTRACT FROM AUTHOR]

The textile industry comprises technologies that transform synthetic or natural fibers into yarn, cloth, and felt for manufacturing clothing, upholstery, and household linens. The major public health threat in tropical and subtropical countries is mosquito‐borne malaria. Nowadays, the demand for insect repellent‐based textiles is continuously rising, as they are used for protection against diseases transmitted by mosquitoes. The present work reviews studies on the fabrication of insect repellent containing electrospun polymeric nanofibers as principal tools for protecting people against mosquito bites. Electrospinning technology is a remarkably facile technique for fabricating polymeric nanofiber devices. The technique is outlined and elucidated. The performance of insect repellent‐based polymeric nanofibers against mosquitoes is carefully reported and comprehensively reviewed in‐depth. Furthermore, the progress made on the mathematical modeling of the release rate of repellents through polymeric nanofiber devices is reviewed. The reviewed studies demonstrate that repellents can be released slowly from electrospun nanofibers, increasing the product's protection period against insects. The reviewed works suggest that electrospinning technology has led to an effective and facile methodology for fabricating functional nanofiber textiles with insect repellent. The reviewed studies showed that product‐based repellents can be effective not only against malaria but also against other mosquito‐borne diseases. [ABSTRACT FROM AUTHOR]