Search Results (30)

Urogenital schistosomiasis, caused by Schistosoma haematobium and transmitted by Bulinus snails, affects approximately 190 million individuals globally and remains a major public health concern. Effective surveillance of snail vectors is critical for disease control, but traditional identification methods are time-intensive and require specialized expertise. Environmental DNA (eDNA) detection using qPCR has emerged as a promising alternative for large-scale vector surveillance. To prevent eDNA degradation, benzalkonium chloride (BAC) has been proposed as a preservative, though its efficacy with schistosomiasis snail vectors has not been evaluated. This study tested the impact of BAC (0.01%) on the stability of Bulinus truncatus eDNA under simulated field conditions. Water samples from aquaria with varying snail densities (0.5–30 snails/L) were stored up to 42 days with BAC. eDNA detection via qPCR and multivariable linear mixed regression analysis revealed that BAC enhanced eDNA stability. eDNA was detectable up to 42 days in samples with ≥1 snail/L and up to 35 days at 0.5 snails/L. Additionally, a positive correlation between snail density and eDNA concentration was observed. These findings support the development of robust eDNA sampling protocols for field surveillance, enabling effective monitoring in remote areas and potentially distinguishing between low- and high-risk schistosomiasis transmission zones. Full article

The trematodes Fasciola hepatica and F. gigantica are transmitted by lymnaeid snails and cause fascioliasis in livestock and humans. Human infection is emerging in southern and southeastern Asia. In India, the number of case reports has increased since 1993. This multidisciplinary study analyzes the epidemiological scenario of human infection. The study reviews the total of 55 fascioliasis patients, their characteristics, and geographical distribution. Causes underlying this emergence are assessed by analyzing (i) the climate change suffered by India based on 40-year-data from meteorological stations, and (ii) the geographical fascioliasis hotspots according to archeological–historical records about thousands of years of pack animal movements. The review suggests frequent misdiagnosis of the wide lowland-distributed F. gigantica with F. hepatica and emphasizes the need to obtain anamnesic information about the locality of residence and the infection source. Prevalence appears to be higher in females and in the 30–40-year age group. The time elapsed between symptom onset and diagnosis varied from 10 days to 5 years (mean 9.2 months). Infection was diagnosed by egg finding (in 12 cases), adult finding (28), serology (3), and clinics and image techniques (12). Climate diagrams and the Wb-bs forecast index show higher temperatures favoring the warm condition-preferring main snail vector Radix luteola and a precipitation increase due to fewer rainy days but more days of extreme rainfall, leading to increasing surface water availability and favoring fascioliasis transmission. Climate trends indicate a risk of future increasing fascioliasis emergence, including a seasonal infection risk from June–July to October–November. Geographical zones of high human infection risk defined by archeological–historical analyses concern: (i) the Indo-Gangetic Plains and corridors used by the old Grand Trunk Road and Daksinapatha Road, (ii) northern mountainous areas by connections with the Silk Road and Tea-Horse Road, and (iii) the hinterlands of western and eastern seaport cities involved in the past Maritime Silk Road. Routes and nodes are illustrated, all transhumant–nomadic–pastoralist groups are detailed, and livestock prevalences per state are given. A baseline defining areas and seasons of high infection risk is established for the first time in India. This is henceforth expected to be helpful for physicians, prevention measures, control initiatives, and recommendations for health administration officers. Full article

WHO promotes the implementation of a comprehensive strategy to control and eliminate schistosomiasis through preventive chemotherapy, snail control, clean water supply, improved sanitation, behaviour change interventions, and environmental management. The transmission of schistosomiasis involves infected definitive hosts (humans or animals) excreting eggs that hatch (miracidia), which infect freshwater snail vectors (also referred to as intermediate snail hosts) living in marshlands, ponds, lakes, rivers, or irrigation canals. Infective larvae (cercariae) develop within the snail, which, when released, may infect humans and/or animals in contact with the water. Snail control aims to interrupt the transmission cycle of the disease by removing the vector snails and, by so doing, indirectly improves the impact of the preventive chemotherapy by reducing reinfection. Snail control was, for many years, the only strategy for the prevention of schistosomiasis before preventive chemotherapy became the primary intervention. Snails can be controlled through various methods: environmental control, biological control, and chemical control. The chemical control of snails has proven to be the most effective method to interrupt the transmission of schistosomiasis. The current review aims to describe the vector snails of human schistosomiasis, present the chemicals and strategies for the control of snails, the challenges with the implementation, and the future needs. Snail control can play a key role in reducing schistosomiasis transmission and, thus, complements other interventions for disease control. There is a need to develop new molluscicide products or new formulations and methods of applications for existing molluscicides that would target snail vectors more specifically. Full article

The emergence of infectious diseases presents a significant global health, economic, and security risk. Climate change can unexpectedly lead to the spread of pathogens, vectors, or hosts into new areas, contributing to the rise of infectious diseases. Surveillance plays a crucial role in monitoring disease trends and implementing control strategies. In this study, we document the first discovery of Heterobilharzia americana, a parasitic schistosome of mammals and its intermediate hosts Galba cubensis and Galba humilis along the banks of the Colorado River in California. We conducted multiple samplings of snails from various locations in the region with a previous history of canine schistosomiasis. Nucleotide sequencing of the multiple regions of the snails’ and parasites’ DNA revealed the coexistence of G. cubensis and G. humilis, both infected with H. americana. Phylogenetic analyses further validate the presence of H. americana in California, suggesting a wider distribution than previously reported. Our findings have implications for public health, veterinary medicine, and biodiversity conservation, contributing to developing effective control strategies to prevent the spread of this emerging infectious disease. Full article

Non-target species are commonly exposed to anticoagulant rodenticides worldwide, which may pose a key threat to declining species. However, the main pathway of exposure is usually unknown, potentially hindering conservation efforts. This study aimed to examine whether baits mixed with the biomarker rhodamine B can be used to track invertebrate consumption of rodenticides in a field environment, using this to observe whether invertebrate prey are a potential vector for anticoagulant rodenticides in the diet of insectivores such as the European hedgehog (Erinaceus europaeus). Rhodamine B baits were found to create an observable response. Uptake was negligible in captured insects; however, 20.7% of slugs and 18.4% of snails captured showed uptake of bait. Maximum temperature, distance from bait, proximity to buildings, and the addition of copper tape to bait boxes all influenced the rate of bait uptake in molluscs. Based on these data, it seems likely that molluscs could be a source of rodenticide poisoning in insectivores. This research demonstrates which prey may pose exposure risks to insectivores and likely environmental factors, knowledge of which can guide effective mitigation measures. We suggest that further investigation into using mollusc repellents around bait boxes should be considered. Full article

In this study, we focused on the eastern part of the Cochlodina laminata range. Although this door snail is widespread in Europe, even a widespread species may lose habitats if future climate change projections are realized. The range shift is one of the consequences of climate change. We applied SDM methods to model the current potential range of C. laminata and the range shift after 40 and after 80 years. We used climatic parameters as predictors. The annual mean temperature has the greatest impact on the modeling results (about 30–60% among models). The precipitation of the warmest quarter also had a high relative importance (about 15–40% among models). For future projections, we considered two shared socio-economic pathways (ssp245 and ssp585). We applied three algorithms: the generalized additive model (GAM), support vector machine (SVM) and multilayer perceptron (MLP) and ensemble prediction. Our projections showed a decrease in habitable area in the eastern part of the range of C. laminata in 40 and in 80 years. According to the forecast, the habitat suitable area will become more fragmented. The range shift with new suitable areas is expected toward the east direction. Full article

Diseases transmitted by mosquitoes and snails cause a large burden of disease in less developed countries, especially those with low-income levels. An approach to control vectors and intermediate hosts based on readily available essential oils, which are friendly to the environment and human health, may be an effective solution for disease control. Guava is a fruit tree grown on a large scale in many countries in the tropics, an area heavily affected by tropical diseases transmitted by mosquitoes and snails. Previous studies have reported that the extracted essential oils of guava cultivars have high yields, possess different chemotypes, and exhibit toxicity to different insect species. Therefore, this study was carried out with the aim of studying the chemical composition and pesticide activities of six cultivars of guava grown on a large scale in Vietnam. The essential oils were extracted by hydrodistillation using a Clevenger-type apparatus for 6 h. The components of the essential oils were determined using gas-chromatography–mass-spectrometry (GC-MS) analysis. Test methods for pesticide activities were performed in accordance with WHO guidelines and modifications. Essential oil samples from Vietnam fell into two composition-based clusters, one of (E)-β-caryophyllene and the other of limonene/(E)-β-caryophyllene. The essential oils PG03 and PG05 show promise as environmentally friendly pesticides when used to control Aedes mosquito larvae with values of 24 h LC_50-aegypti of 0.96 and 0.40 µg/mL while 24 h LC_{50-albopictus} of 0.50 and 0.42 µg/mL. These two essential oils showed selective toxicity against Aedes mosquito larvae and were safe against the non-target organism Anisops bouvieri. Other essential oils may be considered as molluscicides against Physa acuta (48 h LC₅₀ of 4.10 to 5.00 µg/mL) and Indoplanorbis exustus (48 h LC₅₀ of 3.85 to 7.71 µg/mL) and with less toxicity to A. bouvieri. Full article

In myoelectrical pattern recognition (PR), the feature extraction methods for stroke-oriented applications are challenging and remain discordant due to a lack of hemiplegic data and limited knowledge of skeletomuscular function. Additionally, technical and clinical barriers create the need for robust, subject-independent feature generation while using supervised learning (SL). To the best of our knowledge, we are the first study to investigate the brute-force analysis of individual and combinational feature vectors for acute stroke gesture recognition using surface electromyography (EMG) of 19 patients. Moreover, post-brute-force singular vectors were concatenated via a Fibonacci-like spiral net ranking as a novel, broadly applicable concept for feature selection. This semi-brute-force navigated amalgamation in linkage (SNAiL) of EMG features revealed an explicit classification rate performance advantage of 10–17% compared to canonical feature sets, which can drastically extend PR capabilities in biosignal processing. Full article

The Giant African snail (Lissachatina fulica) is listed among the top 100 worst invasive alien species. Native to East Africa, it has been introduced voluntarily or accidentally into more than 50 countries, where it impacts negatively on biodiversity, ecosystems, agriculture, and public health. Here we describe for the first time the finding of a specimen of L. fulica in a protected area of the Cottian Alps (Avigliana Lakes Nature Park, northwest Italy). The snail underwent morphometric analysis and species identification. Given its reproductive characteristics (i.e., hermaphroditism with self-fertilization), it poses a potential threat to the biodiversity of the area and is a vector of zoonotic parasites for humans and animals. Health monitoring of specimens found in the wild and those kept as pets is of crucial importance, as is the establishment of monitoring plans in these areas. Full article

Schistosomiasis, or also generally known as bilharzia or snail fever, is a parasitic disease that is caused by trematode flatworms of the genus Schistosoma. It is considered by the World Health Organisation as the second most prevalent parasitic disease after malaria and affects more than 230 million people in over 70 countries. People are infected via a variety of activities ranging from agricultural, domestic, occupational to recreational activities, where the freshwater snails Biomphalaria release Schistosoma cercariae larvae that penetrate the skin of humans when exposed in water. Understanding the biology of the intermediate host snail Biomphalaria is thus important to reveal the potential spread of schistosomiasis. In this article, we present an overview of the latest molecular studies focused on the snail Biomphalaria, including its ecology, evolution, and immune response; and propose using genomics as a foundation to further understand and control this disease vector and thus the transmission of schistosomiasis. Full article

Modeling and representing 3D shapes of the human body and face is a prominent field due to its applications in the healthcare, clothes, and movie industry. In our work, we tackled the problem of 3D face and body synthesis by reducing 3D meshes to 2D image representations. We show that the face can naturally be modeled on a 2D grid. At the same time, for more challenging 3D body geometries, we proposed a novel non-bijective 3D–2D conversion method representing the 3D body mesh as a plurality of rendered projections on the 2D grid. Then, we trained a state-of-the-art vector-quantized variational autoencoder (VQ-VAE-2) to learn a latent representation of 2D images and fit a PixelSNAIL autoregressive model to sample novel synthetic meshes. We evaluated our method versus a classical one based on principal component analysis (PCA) by sampling from the empirical cumulative distribution of the PCA scores. We used the empirical distributions of two commonly used metrics, specificity and diversity, to quantitatively demonstrate that the synthetic faces generated with our method are statistically closer to real faces when compared with the PCA ones. Our experiment on the 3D body geometry requires further research to match the test set statistics but shows promising results. Full article

A biodiversity survey on three corallivorous snails (Mollusca: Gastropoda) was performed at 28 sites around the island of Bonaire to assess their distribution patterns and associated host corals. The snails and their hosts were identified and counted in three depth zones: 5–10, 10–20, and 20–30 m. The snails were Coralliophila galea and C. salebrosa (Muricidae: Coralliophilinae), and Cyphoma gibbosum (Ovulidae: Simniinae). All three species were widespread around the island without apparent interspecific geographical variation. Coralliophila galea was found exclusively on scleractinian corals, Coralliophila salebrosa almost exclusively on octocorals, and Cyphoma gibbosum only on octocorals. Coralliophila salebrosa showed more dietary overlap with Cyphoma gibbosum than with Coralliophila galea. Coralliophila galea was the most commonly encountered species with the largest number of host species. Owing to its hosts distribution, this species also showed a greater maximum depth and a wider bathymetrical range than the other two snails. The other two snails were shallower and their depth ranges did not differ significantly. Host-coral size did not seem to have influence on the number of snails per host. Coral damage caused by the snails was visible but appeared to be low, causing no mortality in Bonaire, which suggests that the relation with their hosts is more parasitic than predatory. Because these three corallivores have occasionally been reported to occur as outbreaks in other Caribbean localities and may act as vectors in the dispersal of coral diseases, it is recommended that future studies should focus on their population dynamics. Full article

Schistosomiasis is a neglected tropical disease (NTD) caused by blood flukes (Schistosoma spp.). Schistosomatids affect a wide array of vertebrate hosts, including humans. In the present study, multiple species of schistosomatids were identified by isolating schistosomatid cercariae (SC) from naturally infected snails. We also described different biotic and abiotic factors influencing SC infections in snails and reported human cercarial dermatitis (HCD) for the first time in Bangladesh. A total of 22,012 snails of seven species: Lymnaea auricularia, L. luteola, Indoplanorbis exustus, Physa acuta, Viviparus bengalensis, Brotia spp., and Thiara spp., were collected and examined. Among these snails, 581 (2.6%) belonging to five species: L. luteola, L. auricularia, P. acuta, I. exustus, and V. bengalensis, were infected with SC. The rate of infection was the highest for L. luteola (11.1%), followed by L. auricularia (5.3%), and was the lowest for V. bengalensis (0.4%). Prevalence in snails was the highest in September (16.8%), followed by October (9.5%) and November (8.8%), and was the lowest in colder months, such as January (1.8%) and February (2.1%). Infections with schistosomatids were more common in larger snails and snails collected from sunny areas. We confirmed the presence of Schistosoma indicum, S. incognitum, S. nasale, S. spindale, and Trichobilharzia szidati by PCR and sequencing. Through a questionnaire survey, we detected HCD in 214 (53.5%) individuals, and the infection rate was almost equally distributed across all professions. Collectively, the present results suggest that lymnaeid snails are the main vector for Schistosoma spp. prevalent in Bangladesh, and schistosomatids with zoonotic potential are also prevalent. Full article

(1) Background: Schistosomiasis remains a public health issue in Cameroon. Snail control using Niclosamide can prevent schistosome transmission. It is safe to determine lethal concentrations for the population. This study aimed at assessing the toxicity of Niclosamide on different developmental stages of snail populations; (2) Methods: Snails were collected, identified, and reared in the laboratory. Egg masses and adult snails were exposed to Niclosamide, at increasing concentrations (0.06, 0.125, 0.25, 0.5, 1 mg/L for egg embryos and 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2 mg/L for adults). After 24 h exposure, egg masses and snails were removed from Niclosamide solutions, washed with source water and observed; (3) Results: Snail susceptibility was species and population dependent. For egg embryos, Biomphalaria pfeifferi was the most susceptible (LC₅₀: 0.1; LC₉₅: 6.3 mg/L) and Bulinus truncatus the least susceptible (LC₅₀: 4.035; LC₉₅: 228.118 mg/L). However, for adults, B. truncatus was the most susceptible (mortality rate: 100%). The LC₅₀ and LC₉₅ for Bi. camerunensis eggs were 0.171 mg/L and 1.102 mg/L, respectively, and were higher than those obtained for adults (0.0357 mg/L and 0.9634 mg/L); (4) Conclusion: These findings will guide the design of vector control strategies targeting these snail species in Cameroon. Full article

Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC₅₀ of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC₅₀ of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment. Full article