International Journal for Parasitology

Over a quarter of the worlds population is at risk of infection by soil transmitted helminths (STH). Among the STHs Trichuris trichiura infects approximately 7% of people globally, causing a loss of 232,000 DALYS. The main strategy to combat T. trichiura infection focusses on mass drug administration with the benzimidazoles. Whilst albendazole and mebendazole have been effective at reducing the burden of other STHs, the cure rate for whipworm is less than 50% with resistance alleles rising. Glucose is the most studied nutrient in Trichuris spp, however we have no understanding, at the molecular level of the mechanism of uptake in Trichuris spp. We sought to identify putative glucose transporters in Trichuris and investigate how these can be inhibited with phloretin. Using the C. elegans Facilitated Glucose Transporter 1 (FGT) sequence we identified two potential homologs in T. muris (TmGLT) and T. trichiura (TtGLT). We should both proteins contained sequence similarity to FGT1 and contained multiple sequence domains associated with glucose and sugar transport. Further, using Alphafold and molecular docking we show glucose docking sites consistent with transport. To asses the ability of phloretin to inhibit glucose transport, we also performed molecular docking with phloretin, showing possible inhibition. To validate the potential inhibition in vitro we measured the 48h LC50 of phloretin which we showed to be 111 ug/ml against adult T. muris worms, around half that of mebendazole in the same conditions. In contrast phloretin exhibited no effect on worm burden or fecundity in vivo. Together these findings provide the first in silico characterisation of putative glucose transporters in Trichuris spp and have identified glucose transport inhibition as a promising avenue for anthelminthic drug discovery. Whilst further work is required to optimise in vivo efficacy, our results highlight parasite glucose acquisition pathways as potential druggable targets in whipworm.

Anthelmintic resistance in cyathostomins is escalating worldwide, threatening equine health and highlighting the need for sustainable, ecology based parasite control strategies. Chicory (Cichorium intybus, Puna II) has emerged as a promising antiparasitic forage, yet its broader effects on the equine holobiont, parasites, microbiota, and host physiology remain poorly understood. We conducted a 32 day longitudinal grazing trial in young horses to assess how chicory affects parasitological outcomes, gut microbial ecology, nemabiome composition, behaviour, and host physiological and immune responses. Twenty-six naturally infected Anglo-Arabian horses were monitored weekly, with 13 grazing a chicory-based sward and 13 grazing a permanent pasture. Clinical parameters, body weight, and serum biochemistry remained stable across treatments, indicating that chicory was well tolerated. Immune profiles showed limited variation, although IL 10 increased in chicory fed horses, suggesting subtle immune modulation. Behavioural observations revealed no signs of discomfort and indicated slightly enhanced social interactions in the chicory group. Chicory grazing produced a marked reduction in cyathostomin egg excretion, accompanied by species specific shifts in nemabiome composition. Several cyathostomin taxa, including Cylicocyclus ashworthi, C. leptostomus, and C. nassatus, declined in chicory fed horses, whereas certain Cylicostephanus spp increased, indicating differential sensitivity rather than uniform suppression. Concomitantly, chicory induced profound ecological changes in the gut microbiota, including reduced alpha diversity, increased beta dispersion, and destabilised individual microbial trajectories. Several bacterial lineages, particularly Oscillospiraceae, Clostridiaceae, Lachnospiraceae, and Bacteroidales, were differentially enriched, reflecting a functional reorganisation of the intestinal ecosystem. Together, these findings demonstrate that chicory reduces parasite fitness, reshapes nemabiome composition, and alters gut microbial ecology while maintaining host physiological stability. Chicory thus emerges as a promising ecological tool for parasite control, capable of modulating the equine holobiont in ways that complement and potentially reduce reliance on conventional anthelmintic strategies. However, because its effects on gut microbial ecology remain uncertain, and may include shifts resembling dysbiosis, future studies are needed to monitor microbial dynamics more closely and clarify the long term ecological consequences of chicory grazing.

Fasciola hepatica is a trematode parasite responsible for fasciolosis, a liver disease that affects humans and livestock worldwide. Together with other food-borne trematode infections, fasciolosis is considered a neglected tropical disease. Further, it imposes substantial agricultural losses due to infections in ruminants. No vaccine is currently available, and control heavily relies on drug treatment, especially with triclabendazole (TCBZ). However, the intensive use of TCBZ over the past four decades has led to increasing rates of treatment failures and the emergence of drug-resistant parasites. Therefore, the identification of new treatment options is an urgent priority. The currently available toolset for drug screening, however, is limited. To address this need, we established a novel, semi-automated, standardized, and objective screening assay based on motility monitoring of newly excysted juveniles using microscopic live imaging. The assay was validated by testing a panel of ten compounds with known anthelmintic properties, amongst them TCBZ (IC50: 1.5 {micro}M) and the new activator of the F. hepatica transient receptor potential melastatin (TRPM) ion channel, benzamidoquinazolinone (IC50: 1.05 {micro}M). In addition to these two compounds with known activity against F. hepatica, three compounds were identified as particularly promising with a fast onset of action and IC50 values in the nanomolar range: the salicylanilides MMV665807 (IC50: 44 nM), niclosamide (IC50: 32 nM), and its ethanolamine salt, niclosamide ethanolamine (IC50: 9 nM). Complementary live/dead staining revealed that only TCBZ displayed parasiticidal activity, while the other compounds, although leading to parasite paralysis, did not lead to parasite death within 72 hours. Scanning electron microscopy of drug treated parasites did not reveal any significant damage at concentrations corresponding to the IC50s, but strong phenotypes were visible at 20 {micro}M. The presented motility assay provides a robust method for the discovery of novel anthelmintic compounds and facilitates the ongoing effort to combat fasciolosis. Author SummaryFasciola hepatica, the common liver fluke, is a parasitic platyhelminth that infects the liver and biliary ducts of humans and livestock, causing fasciolosis, a Neglected Tropical Disease as defined by the World Health Organization. Triclabendazole is the drug of choice to treat humans and animals. However, its intensive use has led to the emergence of drug resistance resulting in treatment failures worldwide. The identification of novel drugs is therefore urgent. Here, we present a semi-automated and objective method to assess the activity of compounds on one of the key life stages of the parasite: the newly excysted juveniles (NEJ). This stage is highly motile and motility assessment can be exploited to screen for bioactive compounds. Using time-lapse imaging, we quantified NEJ movement after drug exposure. From a panel of ten tested reference anthelmintics, two known fasciolicides (triclabendazole and benzamidoquinazolinone) and three additional compounds (MMV665807, niclosamide, and niclosamide ethanolamine) displayed particularly strong activity and were selected for further investigation. This method represents a robust tool for drug screening and facilitates the discovery of new compounds against F. hepatica.

Neurocysticercosis (NCC), the infection of the central nervous system by Taenia solium larvae, is a leading cause of acquired epilepsy in endemic regions. While viable cysticerci can persist asymptomatically for extended periods, their spontaneous or drug-induced degradation triggers marked perilesional inflammation and severe neurological symptoms. Despite well-documented histopathological characterisation of these lesion states, the host transcriptional programmes associated with viable parasite persistence and early post-treatment lesion disruption remain poorly understood. To address this gap, we performed the first bulk RNA sequencing of pericystic brain tissue using a physiologically relevant porcine model of NCC. Comparing uninfected controls (n = 3), infected untreated pigs with intact viable cysts (n = 6), and antiparasitic-treated pigs with disrupted cysts (n = 3), we identified distinct transcriptional signatures associated with each disease state. Viable infection was associated with broad transcriptional changes (461 upregulated and 175 downregulated genes), characterised by local immune activation alongside suppression of blood-brain barrier (BBB) remodelling, vascular, and neuronal signalling molecular signatures. The post-treatment state with confirmed BBB disruption was associated with a smaller but directionally distinct response (160 upregulated and 57 downregulated genes), marked by inflammatory signalling and increased expression of genes associated with endothelial activation, vascular regulation, and BBB-associated remodelling. Together, these findings suggest that, while immune engagement is a feature shared across both lesion states, the BBB-associated transcriptional axis shifts substantially following treatment. These results provide an exploratory transcriptomic framework for understanding parasite persistence, treatment-induced neuroinflammation, and neurovascular remodelling in NCC, and highlight candidate pathways and genes for future mechanistic investigation.

Motility of Plasmodium sporozoites (SPZs) in the skin is a key determinant of successful host infection. Earlier studies have described rapid movement of both murine and human SPZs in skin following syringe inoculation. It is typical to classify SPZ trajectories into ``motile'' and ``immotile'' and restrict the analysis of movement patterns to motile SPZs. Because criteria to define motile SPZs are dependent on the study and are often qualitative, it remains unclear if sub-selection of motile tracks introduces biases in characterization of SPZ movement in vivo. We processed imaging data (22 movies) from a recent study of movement of P. falciparum (Pf) and P. yoelii (Py) SPZ in skin. We proposed a novel metric -- maximal spatial spread (MSS or S) --- that is the maximum Euclidean distance between any two recorded positions in a trajectory. We used MSS to classify SPZ trajectories as immotile (S<Sthreshold) or motile (S>Sthreshold) for a given threshold value Sthreshold. Larger Sthreshold values naturally resulted in a smaller fraction of tracks classified as motile, and subsequently, in an increased overall displacement, instantaneous and mean speeds, decreased mean turning angle, and higher initial slopes of the mean squared displacement (MSD) curves. We found that at intermediate values of Sthreshold Pf SPZs had a lower average speed than Py SPZs suggesting that host environment may impact SPZ movement. Both species exhibited a small but statistically significant decline in average speed with time after inoculation but this was also dependent on the Sthreshold value. Our analysis of MSD curves and turning angle distributions suggests that both Pf and Py SPZs undergo correlated random walks -- a type of Brownian walk with short-term superdiffusive displacement. By using a novel methodology of hidden Markov models (moveHMM package in R) we found that SPZ movement is best described by three movement states; however, none of these states corresponded to previously described circling gliding. Taking together, our results suggest that inference of SPZ movement patterns depends on the criteria used to define tracks as motile or immotile. Standardized preprocessing criteria are therefore important when comparing motility across Plasmodium species, experimental time points, or laboratories. Analysis of turning angle distributions and application of hidden Markov models provided additional metrics to quantify distinct modes of SPZ movement in vivo.

Anthelmintic drugs are used to control soil-transmitted helminths that infect a third of the worlds human population. There is increasing concern about the development of resistance to anthelmintic drugs because of the limited number of compounds available and there is an unmet need for new resistance-busting drugs. Here we describe the presence of a previously unrecognized endogenous acetylcholine analogue, {beta}-alanine betaine, which may serve as an endogenous ligand for an alternate subfamily of nicotinic receptors (DEG-3/DES-2) that could be developed as novel drug targets because their analogues are not present in their human or animal hosts. We collected peri-enteric fluid from female Ascaris suum (a model for the human parasite, Ascaris lumbricoides) and subjected it to chromatography and MS/MS to reveal signals consistent with acetylcholine, choline, and {beta}-alanine betaine but we did not recover betaine. We injected betaine into female Ascaris suum which produced no effect. However, injection of {beta}-alanine betaine, produced characteristic pretzel coiling and injection of levamisole produced a rod-like spastic paralysis. The differences between {beta}-alanine betaine and levamisole suggested that they activate different nAChRs subfamilies. PCR showed that messages of the DEG-3 subfamily of nAChR channels, which are betaine targets and were present in the intestine and body wall of A. suum. Calcium signaling experiments showed that {beta}-alanine betaine increased intracellular calcium of the intestine enterocytes and electrophysiology of the body muscle cells demonstrated that {beta}-alanine betaine produced membrane potential depolarization. In N2 elegans, application of {beta}-alanine betaine produced gradual inhibition of motility, which was reduced in acr-20, acr-23, des-2, deg-3 and lgc-41 null-mutants. These observations suggest that, in addition to acetylcholine, {beta}-alanine betaine - an anaerobic analog of betaine - may function as an endogenous ligand in anaerobic nematodes such as A. suum. An expanded repertoire of nicotinic acetylcholine receptor subfamilies in nematodes relative to mammals may reflect a corresponding need for diversification of cholinergic endogenous ligands in these organisms. This repertoire could allow their simpler neuronal system to perform more complex controls and be exploited for development of different and novel subfamily selective cholinergic anthelmintics.

The recent shift in Bangladesh from tradition backyard rearing system to modern commercial layer farming has made the birds immune to infectious diseases. Pediculosis, however, continues to pose a challenge in modern production system due to its invasive nature, often going unnoticed and neglected as it is typically non-lethal, yet capable of causing significant production losses. Lice infestation is a persistent threat in poultry production; however, its implications in battery-caged commercial layer hens in Bangladesh remain insufficiently characterized. The study aimed to identify the causative louse species and evaluate its associations with clinical pathology, hematological alteration and productive performance in 30 white-feathered (15 infested + 15 non-infested) and 30 brown-feathered (15 infested + 15 non-infested) laying birds from two commercial farms in Tangail. Morphological characterization confirmed the parasite as Menacanthus stamineus, distinguished by a dorsoventrally flattened body, parabolicallly rounded head wider than long, concealed club-shaped antennae, an oblong-oval abdomen with fine setae and three pairs of short legs each bearing paired claws. Infested birds exhibited consistent clinical pathology, including pale combs, petechial hemorrhages around the vent, severe feather damage with alopecic and exudative areas and incidence of irregular and broken-shelled eggs. Production performance analysis revealed significant reduction in hen-day egg production, egg weight, and feed intake, accompanied by significantly increased feed conversion ratios. Hematological evaluation demonstrated significantly reduced hemoglobin concentration, hematocrit and erythrocyte counts in infested hens, indicating mild anemia and compromised oxygen-carrying capacity. Collectively, pediculosis was strongly associated with lice-induced self-inflicted injury and cannibalism, systemic physiological stress, impaired erythropoiesis, reduced production efficiency and compromised welfare in caged laying hens. To best of our knowledge, it was the first integrative reports from Bangladesh documenting M. stramineus infestation in battery-caged commercial layer system with concurrent evidence of hematological disruption and measurable productivity losses, underscoring its epidemiological and economic significance and urgent need for targeted, evidence-based ectoparasite control strategies.

In many leishmaniasis foci, reservoirs that maintain infection remain unknown. Here, we developed a field-applicable toolkit based on the analysis of individual blood fed sand flies (IBF) to identify reservoirs. Sand flies were given a Leishmania donovani-infected first blood meal (iBM1) by feeding artificially on a membrane or naturally on a clinically ill animal followed by two subsequent uninfected blood meals (BMS+). Bulk-RNAseq was used to identify two target parasite genes, sherp and a novel hypothetical gene (HPB), which exhibited a significantly higher expression in BMS+ compared to iBM1 sand flies. DNA and RNA were co-extracted from IBF. DNA was used to detect Leishmania infection and the blood meal source; RNA was used to assess expression of target genes by qRT-PCR. Linear discriminant analysis (LDA) of target gene expression classified sand fly specimens based on their iBM1 or BMS+ status. Co-extraction yielded a mean of >800ng per IBF for DNA and RNA. We detected [&ge;]1 parasite/s by kDNA qPCR and ssu rRNA RT-qPCR. LDA identified iBM1 parasites with a predictive accuracy of [~]87% and [~]82%, in membrane or naturally fed sand flies, respectively. This toolkit provides an innovative approach to identification of leishmaniasis reservoirs informing targeted control strategies.

Wildlife hosts play important roles in the ecology and transmission of vector-borne parasites, yet information on host associations remains scarce in many biodiverse tropical regions. Within a One Health framework, characterizing parasite diversity in wildlife can improve understanding of ecosystem health and disease emergence. Road-killed animals provide a non-invasive opportunity to investigate host-parasite interactions while minimizing disturbance to natural habitats. We screened 127 liver and intestinal tissue samples obtained from 76 road-killed vertebrates collected near protected areas in two Ecuadorian biodiversity hotspots, the Tropical Andes and Choco-Darien, for trypanosomatids and other vector-borne microorganisms. Molecular analyses targeted the 18S rRNA and cytochrome b genes of trypanosomatids and included additional screening for Trypanosoma cruzi, Trypanosoma rangeli, Rickettsia spp., and piroplasmids. Twenty-nine samples were positive for kinetoplastids. We detected diverse trypanosomatids representing the genera Leishmania, Porcisia, Trypanosoma, Phytomonas, Blastocrithidia, and Obscuromonas, as well as free-living kinetoplastids of the order Neobodonida. The most frequently detected species was Leishmania amazonensis, identified in 17 samples from at least 13 species of birds, reptiles, and caecilians, predominantly in liver tissue, suggesting previously unrecognized host associations. We also identified a putatively novel species of Porcisia and three potentially undescribed avian trypanosomes belonging to the subgenus Ornithotrypanum. No evidence of T. cruzi, T. rangeli, Rickettsia spp., or piroplasmids was found. Our findings identify birds, reptiles, and caecilians as potential reservoir hosts of L. amazonensis. In addition, we substantially expanded current knowledge of kinetoplastid diversity in Ecuadorian wildlife. This study demonstrates the value of road-killed animals as a practical, non-invasive resource for wildlife pathogen surveillance and highlights the importance of integrating biodiversity research into One Health approaches to better understand parasite transmission dynamics in rapidly changing tropical ecosystems. Author summaryMany parasites that affect humans circulate naturally in wildlife, but identifying their animal hosts is often difficult in remote, biodiverse regions. We used road-killed animals as a non-invasive source of biological material to investigate parasites in wildlife from two biodiversity hotspots in Ecuador. By analyzing tissues from birds, reptiles, amphibians, and mammals, we found a remarkable diversity of kinetoplastid flagellates, a group that includes the agents of Chagas disease and leishmaniasis. Although we did not detect human-infective trypanosomes, we repeatedly identified Leishmania amazonensis (a species causing human disease) in birds, reptiles, and caecilians. These vertebrate groups have not previously been recognized as potential hosts of this parasite. We also discovered several undescribed trypanosomatid species, emphasizing how little is known about parasite diversity in tropical wildlife. Our results show that road-killed animals can provide valuable information on host-parasite interactions without disturbing living populations. Such surveillance contributes to One Health efforts by improving our understanding of how environmental change, wildlife, and human health are interconnected.

Predators are often considered regulators of disease in prey populations, a concept central to the "healthy herd hypothesis". This hypothesis suggests that by preferentially removing infected individuals, predators can reduce parasite prevalence. However, predators may also act as disease vectors, facilitating the spread of parasites. We investigated whether stickleback fish (Gasterosteus aculeatus) can act as vectors for the transmission of the obligate bacterial parasite Pasteuria ramosa to its Daphnia host, a widespread freshwater zooplanktor. We fed infected D. magna to sticklebacks, and subsequently analysed faecal samples for the presence, viability, and infectivity of parasite transmission stages (= spores). We recovered approximately 60% of the consumed spores from fish faeces and these spores did not suffer from reduced infectivity to D. magna. Additionally, spores associated with sloppy feeding did not reduce infection rates. Thus, consumption of infected hosts by fish does not eliminate the parasite, but in contrary, may contribute to the spread and persistence of P. ramosa in natural populations, potentially influencing parasite dynamics in natural freshwater ecosystems.

Nutritional symbionts can be essential for their animal hosts. The bacterial symbiont of the leaffooted bug, Leptoglossus zonatus, Caballeronia, is acquired from the environment each generation in the 2nd instar. The symbiont is critical for L. zonatus: aposymbiotic bugs are unable to reproduce. We hypothesized that symbiotic bugs excrete Caballeronia where juveniles might find and consume them. We inoculated L. zonatus with GFP-labelled Caballeronia and examined feces of each life stage. We found that Caballeronia is excreted almost exclusively in the adult stage. We then asked if 2nd instar nymphs could acquire Caballeronia from feces. Nymphs were provided with a) feces from adults fed GFP-labelled Caballeronia, b) GFP-Caballeronia in culture, or c) water only. We found that feces-fed bugs had similar rates of symbiont acquisition to those fed Caballeronia in culture, indicating that feces can be a source of Caballeronia for L. zonatus. However, compared to culture fed individuals, bugs fed feces had reduced survivorship and required longer to develop, and surviving adults had reduced mass. Bacterial motility assays showed that in contrast to cultured Caballeronia cells, Caballeronia in feces were non-motile. These results show suggest that feces can be a source of Caballeronia, at least in some environments, however transmission mode can influence success of the offspring.

Despite extensive efforts to understand the population biology and ecology of the African malaria mosquitoes questions regarding their movement pattern, survival, and population size persist, reflecting methodological limitations. Site fidelity, in which mosquitoes return to feeding sites, resting sites, or oviposition sites remain debated. Mark release recapture (MRR) studies are vital to address such questions. Using locality- and date-specific DNA tags in fluorescent spray, we carried out a continuous MRR in a Malian village from September to December 2019 with three days interval between capture and release across seven zones. A total of 12,937 Anopheles gambiae s.l. (7,455 females) were captured during 35 indoor collections. Handling related mortality was 3.4%., A. coluzzii predominated (89.7%), followed by A. gambiae (9.4%), and A. arabiensis (0.9%). Overall recapture rate was 1.05% (N=129). Contrary to the site-fidelity hypothesis, the distribution of recaptured mosquitoes across zones (regardless of their zone of release) was similar to the distribution of the captured mosquitoes (r=0.97, P<0.001), with 70% recaptured in a different zone. There was no difference in distance moved between sexes, but males average distance increased over time since release, whereas females distance remained unchanged. Simulated movements (across released points), with equal probability to reach any of the village houses predicted actual distance moved by mosquitoes. The regression of observed distance from each zone over predicted had a slope of 1 (r2=94%, P=0.006), suggesting that the layout of the capture area greatly affected the results. The average days post release (minimum age of wild captured mosquitoes) for recaptures was 6.4 d with the longest being 30 d. No seasonal and sex related difference in minimum age were detected. The corrected probability of daily survival (PDS) was 94% and the daily increase in sporozoite rate was 4.9%. Limiting the recapture duration period showed that PDS increased with recapture duration from 74% to 86% (12 to 30 d, uncorrected). Thus, larger recapture area and longer recapture duration are needed to obtain accurate estimates of movement range and of daily survival.

Free-roaming dog populations pose challenges to public health and animal welfare, and their management and protection is legally mandated in many countries to control zoonotic diseases such as rabies, reduce bites, mitigate fear of aggressive dogs, and preserve animal welfare. Although international organisations recommend holistic dog population management with surgical sterilisation as a key component, stakeholders report a lack of evidence-based guidance on effective and cost-efficient strategies. To address this, we developed a deterministic model of a closed free-roaming dog (FRD) population, including dogs dependent on and independent of humans, parameterised using data from southern India. We evaluated a wide range of sterilisation strategies varying duration, interval, frequency, intensity, targeting different population subsets, and fixed or responsive approaches. Strategies were assessed based on their effects on independent FRD population size and implementation costs. Female sterilisation coverage (FSC) strongly determined population reduction and cost-effectiveness. Repeated, short sterilisation periods with appropriately timed intervals and high early intensity best balanced population reduction and cost-efficiency. Excluding dependent dogs (cared for by humans) severely constrained population reduction, while male sterilisation enhanced impact at little extra cost, assuming direct effects on pregnancy rates. Costs and population impacts can be visualised on an interactive web application (https://field.shinyapps.io/DogPopSimApp), allowing practitioners and policymakers to explore sterilisation strategy outcomes. Overall, cost-effective population reduction required sustained commitment and coverage-driven strategies that balance welfare, population reduction and the operational needs of dog-mediated rabies control.

Plant-parasitic nematodes (PPNs) are among the most destructive agricultural pests worldwide, causing significant economic losses across diverse cropping systems. Soil fumigation, the most common management strategy, is costly, detrimental to soil health, and increasingly restricted due to environmental and regulatory concerns. As a result, there is a critical need for alternative, sustainable approaches for PPN control. Solanum sisymbriifolium is resistant to several Meloidogyne species and represents a promising source of natural nematicidal compounds. In this study, we evaluated the effects of S. sisymbriifolium extracts on Meloidogyne chitwoodi and M. hapla, two economically important nematodes. Compounds were extracted using solvents of increasing polarity and then reconstituted in water. The water-solubilized extracts were then used in bioassays to assess their effects on nematode egg hatching, egg viability, and second-stage juvenile (J2) survival. Egg hatching and J2 viability of both Meloidogyne species were consistently affected by compounds in the 1-butanol fraction. Further characterization of these compounds may enable the development of novel, environmentally sustainable alternatives to conventional nematode management strategies.

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops in Nigeria, serving as a major source of income, nutrition, and raw material for food industries. However, its production is severely constrained by Fusarium wilt, a destructive soil-borne disease caused by Fusarium oxysporum f. sp. lycopersici. This study investigated the prevalence and severity of Fusarium wilt on tomato in Chikun Local Government Area (LGA) of Kaduna State, Nigeria. Field survey and laboratory analyses were conducted on forty-five tomato samples from three tomato farms Kujama, Kakau, and Rido. The samples were examined for disease incidence and severity. Data were analyzed using descriptive statistics and Chi-square tests. The overall disease incidence was with Rido recording the highest infection rate (80.0%), followed by Kujama (60.0%) and Kakau (40.0%). Among plant parts, the stem exhibited the highest infection frequency (80.0%), while leaves and fruits had 60.0% and 40.0% incidence respectively. Chi-square analysis indicated no significant difference (p > 0.05) in disease incidence among farms and plant parts, suggesting uniform pathogen distribution. The research recommends the adoption of integrated disease management strategies and improved farmer awareness to mitigate the impact of the disease and ensure sustainable tomato production.

Rift Valley fever (RVF) is a mosquito-borne disease that can cause severe illness and death in both humans and livestock. Since 2016, Uganda has experienced recurrent but localized RVF outbreaks concentrated in the countrys southwestern region. The ecological drivers of this emergence remain unclear, as outbreaks have occurred throughout the year and show little association with meteorological patterns. We evaluated whether crop cultivation, particularly banana cultivation, is associated with RVF outbreak occurrence after controlling for likely confounders. We conducted a longitudinal study of human-inhabited 5 x 5 km grid cells across southwestern Uganda from 2016-2024. Annual Sentinel-2 satellite imagery composites were used to classify land cover into banana, coffee, ground crops, and non-crop categories, and the proportion of each land type was calculated for every grid-cell year. Because land cover proportions are compositional, isometric log-ratio transformations were used to estimate the independent effects of each land type. Confounding was addressed through propensity weighting, and crop substitution effects were estimated using g-computation. Banana land cover was the only land type consistently associated with increased RVF outbreak likelihood. In grid-cell years with low baseline banana cover, a 10-percentage point substitution from other land classes into banana was associated with a 1.64-fold increase in the odds of an RVF outbreak (95% CI: 1.17-2.29). In a simplified banana-only model, each 10-percentage point increase in banana cover was associated with a 1.21-fold increase in outbreak odds (95% CI: 1.02-1.43). Holding banana cover constant, substitutions among coffee, ground crop, and non-crop land showed weak or null associations. These findings suggest that banana cultivation may be an important ecological feature influencing RVF transmission dynamics and outbreak risk in southwestern Uganda. Author SummaryRift Valley fever (RVF) is a mosquito-borne disease that affects both humans and livestock and has caused repeated outbreaks in southwestern Uganda since 2016. While rainfall and flooding are often linked to RVF outbreaks elsewhere, Ugandas recent outbreaks have occurred across seasons and are not well explained by weather patterns alone. We investigated whether agricultural land use could help explain where outbreaks occur. Using satellite imagery from 2016-2024, we measured the amount of banana cultivation, coffee cultivation, ground crops, and non-crop land across southwestern Uganda and evaluated their association with RVF outbreak occurrence. We found that areas with greater banana cultivation were consistently more likely to experience RVF outbreaks, even after accounting for environmental and demographic factors. In contrast, coffee, ground crops, and non-crop land showed little evidence of an independent association with outbreak risk. These findings suggest that banana cultivation may create ecological conditions that favor RVF transmission. Rather than indicating that bananas themselves cause disease, the results point to banana-growing landscapes as potential environments where interactions among mosquitoes, livestock, and humans may increase transmission opportunities. Understanding these local ecological drivers could help improve surveillance, risk assessment, and prevention strategies for RVF in Uganda and other endemic regions.

The tick Ixodes ricinus is the main vector of human and animal pathogens in Europe. Despite its importance in epidemiology and medicine, our understanding of physiological mechanisms controlling blood feeding, osmoregulation, or development are still limited. Here, we identify novel neuropeptide invertebrate parathyroid hormone-like peptide (iPTH) and its two receptors - PTHR1 and PTHR2 in I. ricinus. Functional aequorin-based assay confirmed specific activation of both receptors by iPTH. Using RT-qPCR we detected the PTHR1 transcript in the synganglion, while increased expression levels of PTHR2 were found in the salivary glands, hindgut and female gonads. RNA-mediated knockdown of iPTH receptors in nymphs resulted in delayed blood feeding, and a high incidence of defects in adult ecdysis. Consistent with observed phenotypes, iPTH is expressed in multiple neurons of the synganglion which project arborizing axons to the salivary glands, rectal sack and skeletal muscles. iPTH was colocalized with orcokinin-immunoreactivity (OK-IR) in all neurons that innervate these peripheral tissues. iPTH is further colocalized with tachykinin (TK) in Pd1DL1 neurons, suggesting coordinated action with other neuropeptides. Our findings indicate that iPTH signaling is required for normal feeding, development and successful ecdysis.

The migratory endoparasitic pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease, causing significant economic and ecological losses in conifer forest ecosystems in Europe and Asia. Understanding the molecular mechanisms regulating PWN parasitism-related genes may lead to new sustainable solutions for control. Based on previous PWN transcriptomic datasets from the pre-parasitic and parasitic stages and from the pharyngeal gland cells (GC), an in silico analysis was performed to identify transcription factors (TF) highly expressed in the GC. Seven candidates TF genes were selected, and their spatial expression validated by in situ hybridisation. From those, two GC-expressed TFs, BXY_079 and BXY_022, each encoding zinc finger domains, were successfully knocked down by RNA interference. Transcriptomic data from silenced BXY_079 and BXY_022 TFs, analysed with existing life cycle specific transcriptomic data, showed that both TFs control genes expressed at similar times, by repressing male-related genes while activating genes expressed during the J3 and D3 stages, yet each represents the extreme of the others minor function. In addition to these common roles, BXY_079 also activates parasitism-related genes in the J2 stage. These BXY_079-activated parasitism-related genes predominantly encode proteins with lytic functions, including secreted peptidases and glycoside hydrolases. Consistent with their proposed role in parasitism, these genes are highly expressed during the parasitic juvenile stages and are likely involved in nematode feeding, tissue penetration, and migration within the host. In contrast, BXY_022 also represses the expression of several genes related to the reproduction system, such as major sperm proteins and cytosolic motility proteins, particularly in the adult male stage. Taken together, both dual-functional TFs work together, non-redundantly, to regulate gene expression across the life cycle, while each is additionally specialised to regulate diverse and distinct gene sets: ranging from genes implicated in lytic parasitic functions to sexual dimorphism.

RNA interference (RNAi) is a widely exploited reverse-genetics tool with potential uses for disease control. Successful RNAi has been reported in trematode-vectoring snails, but the composition of RNAi effector-encoding gene complements, a key driver for RNAi efficiency, remain unstudied in these species. Using bioinformatics and comparative genomics, we searched for orthologues of 115 RNAi effector sequences in genomes or transcriptomes of four snail vectors: Biomphalaria glabrata, B. pfeifferi, Bulinus truncatus, and Lymnaea staginalis. Gene expression patterns of selected RNAi effectors were then examined across developmental stages and tissues of the model B. glabrata snail. At least 74 RNAi-related proteins were conserved across all four species, including core components known to be essential for gene silencing. Classical systemic RNAi-deficient (SID) genes that facilitate systemic RNAi in other systems were absent, suggesting that alternative pathways may compensate for dsRNA uptake and transport. Core effectors of secondary RNAi amplification and heritable RNAi were not detected. Expressions of Dicer-1, Argonaute-2, and the exonuclease Eri-1 did not vary significantly with snail size. A putative RNAi-inhibiting Staufen orthologue showed elevated expression in the ovotestis, while another putative cholesterol-interacting gene was overexpressed in the trunk tissue and may partly contribute to RNAi import. Altogether, our results present the most comprehensive overview of RNAi pathway effectors in major intermediate snail hosts for trematodes. The findings underscore the likely broad potential for RNAi use in trematode intermediate hosts as an experimental tool and potential control method.

Background: Dirofilaria repens is a zoonotic parasite expanding unnoticed across Europe due to climate change. We hypothesised that in this process, the Carpathian Basin has a facilitating effect. Methods: Using 426 georeferenced European cases, the probability of infection occurrence was determined in relation to climatic factors, surface water availability, regional social deprivation, and stray dog population density. To analyse the potential impacts of ecological and social factors (deprivation and stray dog population density), the MaxEnt algorithm, and spatial Empirical Bayes smoothing and Bivariate Local Indicators of Spatial Association (BiLISA) index calculation were employed, respectively. Results: MaxEnt analysis revealed that the mean warmest month temperature (22.8 - 25.1 oC), winter mean minimum temperature (> -2.1 oC), and summer precipitation (28.6 - 231 mm) have the strongest impact on the probability of the parasite's occurrence in Europe. Social factors have significance in the eastern Balkans and the Carpathian Basin, but not in Western Europe. The Carpathian Basin appears to be a hotspot, similar to Mediterranean coastal areas. Furthermore, the Danube Valley acts as an ecological corridor for subtropical vector-borne parasites. Conclusions: Our findings confirm that summer warmth is the primary ecological driver of the parasite's range expansion, which is facilitated by the Carpathian Basin due to climatic and socioeconomic conditions.