Silver and gold nanoparticles as a novel approach to fight Sarcoptic mange in rabbits.

Various kinds of pets have been known to contract the ectoparasite Sarcoptes scabiei. Current acaricides are becoming less effective because of the resistance developed by the mite besides their adverse effects on the general activity and reproductive performance of domestic pets. For this reason, the present study aims to discover a novel and safe approach using silver and gold nanoparticles to fight Sarcoptic mange in rabbits as well as to explain their mechanism of action. 15 pet rabbits with clinical signs of Sarcoptic mange that were confirmed by the microscopic examination were used in our study. All rabbits used in this study were assessed positive for the presence of different developing stages of S. scabiei. Three groups of rabbits (n = 5) were used as follows: group (1) didn't receive any treatment, and group (2 and 3) was treated with either AgNPs or GNPs, respectively. Both nanoparticles were applied daily on the affected skin areas via a dressing and injected subcutaneously once a week for 2 weeks at a dose of 0.5 mg/kg bwt. Our results revealed that all rabbits were severely infested and took a mean score = 3. The skin lesions in rabbits that didn't receive any treatments progressed extensively and took a mean score = of 4. On the other hand, all nanoparticle-treated groups displayed marked improvement in the skin lesion and took an average score of 0-1. All NPs treated groups showed remarkable improvement in the microscopic pictures along with mild iNOS, TNF-α, and Cox-2 expression. Both nanoparticles could downregulate the m-RNA levels of IL-6 and IFγ and upregulate IL-10 and TGF-1ß genes to promote skin healing. Dressing rabbits with both NPs didn't affect either liver and kidney biomarkers or serum Ig levels indicating their safety. Our residual analysis detected AgNPs in the liver of rabbits but did not detect any residues of GNPs in such organs. We recommend using GNPs as an alternative acaricide to fight rabbit mange.

Assessment of the in vitro acaricidal activity of Bravecto® (fluralaner) and a proposed orange oil-based formulation vehicle for the treatment of Sarcoptes scabiei.

BACKGROUND: Sarcoptic mange is a serious animal welfare concern in bare-nosed wombats (Vombatus ursinus). Fluralaner (Bravecto®) is a novel acaricide that has recently been utilised for treating mange in wombats. The topical 'spot-on' formulation of fluralaner can limit treatment delivery options in situ, but dilution to a volume for 'pour-on' delivery is one practicable solution. This study investigated the in vitro acaricidal activity of Bravecto, a proposed essential oil-based diluent (Orange Power®), and two of its active constituents, limonene and citral, against Sarcoptes scabiei. METHODS: Sarcoptes scabiei were sourced from experimentally infested pigs. In vitro assays were performed to determine the lethal concentration (LC50) and survival time of the mites when exposed to varying concentrations of the test solutions. RESULTS: All compounds were highly effective at killing mites in vitro. The LC50 values of Bravecto, Orange Power, limonene and citral at 1 h were 14.61 mg/ml, 4.50%, 26.53% and 0.76%, respectively. The median survival times of mites exposed to undiluted Bravecto, Orange Power and their combination were 15, 5 and 10 min, respectively. A pilot survival assay of mites collected from a mange-affected wombat showed survival times of < 10 min when exposed to Bravecto and Orange Power and 20 min when exposed to moxidectin. CONCLUSIONS: These results confirm the acaricidal properties of Bravecto, demonstrate acaricidal properties of Orange Power and support the potential suitability of Orange Power and its active constituents as a diluent for Bravecto. As well as killing mites via direct exposure, Orange Power could potentially enhance the topical delivery of Bravecto to wombats by increasing drug penetration in hyperkeratotic crusts. Further research evaluating the physiochemical properties and modes of action of Orange Power and its constituents as a formulation vehicle would be of value.

Risk factors for scabies in hospital: a systematic review.

BACKGROUND: Annually, 175.4 million people are infected with scabies worldwide. Although parasitic infections are important nosocomial infections, they are unrecognized compared to bacterial, fungal, and viral infections. In particular, nonspecific cutaneous manifestations of scabies lead to delayed diagnosis and frequent nosocomial transmission. Hospital-based studies on the risk factors for scabies have yet to be systematically reviewed. METHODS: The study followed the PRISMA guidelines and was prospectively registered in PROSPERO (CRD42023363278). Literature searches were conducted in three international (PubMed, Embase, and CINAHL) and four Korean (DBpia, KISS, RISS, and Science ON) databases. We included hospital-based studies with risk estimates calculated with 95% confidence intervals for risk factors for scabies infection. The quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tools. Two authors independently performed the screening and assessed the quality of the studies. RESULTS: A total of 12 studies were included. Personal characteristics were categorized into demographic, economic, residential, and behavioral factors. The identified risk factors were low economic status and unhygienic behavioral practices. Being a patient in a long-term care facility or institution was an important factor. Frequent patient contact and lack of personal protective equipment were identified as risk factors. For clinical characteristics, factors were categorized as personal health and hospital environment. People who had contact with itchy others were at higher risk of developing scabies. Patients with higher severity and those with a large number of catheters are also at increased risk for scabies infection. CONCLUSIONS: Factors contributing to scabies in hospitals range from personal to clinical. We emphasize the importance of performing a full skin examination when patients present with scabies symptoms and are transferred from settings such as nursing homes and assisted-living facilities, to reduce the transmission of scabies. In addition, patient education to prevent scabies and infection control systems for healthcare workers, such as wearing personal protective equipment, are needed.

The most effective systemic treatment in dogs with sarcoptic mange: a critically appraised topic.

BACKGROUND: Sarcoptic mange is a common, pruritic parasitic skin disease of dogs. Due to its highly contagious character, it represents a potential veterinary and public health risk. Because of clinical similarity with other diseases, cross-antigenicity, and low sensitivity of available diagnostic methods, therapeutical trial is frequently used to confirm the disease. Considering the variety of available acaricidal molecules as well as the need to use the most effective treatment, the present paper reviews evidence comparing different types of systemic treatment of canine scabies. RESULTS: Analysis of the results showed that afoxolaner, fluralaner and sarolaner as well as several macrocyclic lactones such as selamectin, moxidectin and milbemycin oxime can lead to parasitological and clinical cure. CONCLUSION: The similarity in the clinical and parasitological efficacy of these substances enhances the need for comparative studies, which could allow the identification of the most efficacious product.

Can Ivermectin kill Sarcoptes scabiei during the molting process?

BACKGROUND: Sarcoptes scabiei is a permanent obligate ectoparasite that lives and reproduces in the epidermis of humans and other mammals worldwide. There is a lack of information on the molting process of Sarcoptes scabiei. Ivermectin is widely used to treat Sarcoptes infection in humans and animals, while the survival of molting Sarcoptes mites in the presence of ivermectin is unknown. The aim of the present study is to investigate the molting process of Sarcoptes mites and assess the activity of ivermectin during the molting process of Sarcoptes mites. METHODOLOGY/PRINCIPAL FINDINGS: molting Sarcoptes mites were incubated at 35°C and 80% relative humidity and observed hourly until complete molt. Of the 192 molting mites recorded, the longest molt periods for larvae and nymphs were 23 and 30 h, respectively. The activity of ivermectin on molting Sarcoptes mites was also assessed using two concentrations of the drug (0.1 and 0.05 mg/ml). The exposure time for molting mites was determined by 100% mortality of female mites exposed to the solution of ivermectin. While all female mites were killed after exposure to 0.1 mg/ml ivermectin for 2 h and and 0.05 mg/ml for 7 h, 32% and 36% of molting mites survived and successfully molted, respectively. CONCLUSIONS/SIGNIFICANCE: The present study demonstrated that molting Sarcoptes mites are less susceptible to ivermectin than active mites. As a consequence, mites may survive after two doses of ivermectin given 7 days apart due not only to hatching eggs but also to the resistance of mites during their molting process. Our results provide insight into the optimal therapeutic regimens for scabies and highlight the need for further research on the molting process of Sarcoptes mites.

Co-infection patterns in the ectoparasitic community affecting the Iberian ibex Capra pyrenaica.

BACKGROUND: Sarcoptic mange is one of the main parasitic diseases affecting the Iberian ibex Capra pyrenaica. Scabietic animals suffer a decline in body condition and reproductive fitness and in severe cases may die. Although several previous studies of the pathology of this disease and the physiological changes it produces in ibex have been carried out in recent years, our knowledge of the relationship between Sarcoptes scabiei and other ectoparasites of this host is still limited. METHODS: We analysed 430 Iberian ibex skin samples. Ectoparasites were removed, counted and identified. Mite (S. scabiei) numbers were obtained after digesting the skin samples in a 5% KOH solution. We modelled mite numbers in terms of host sex and age, site, year, season and the presence of other ectoparasites such as ticks and lice using generalized linear mixed models (GLMMs) and ectoparasite co-occurrence patterns using two different models: the probabilistic model species co-occurrence and the generalized linear latent variable model (GLLVM). RESULTS: The ectoparasite community was mainly composed of S. scabiei, six ticks (Haemaphysalis sulcata, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus turanicus, Dermacentor marginatus and Ixodes ricinus) and two lice (Bovicola crassipes and Linognathus stenopsis). Adult male ibex harboured more mites than females. Mite numbers varied greatly spatially and seasonally and increased with the presence of other parasites. Some positive co-occurrence relationships between pairs of different ectoparasites were observed, particularly between ticks. The presence of S. scabiei negatively affected lice and H. sulcata numbers. CONCLUSIONS: Sarcoptic mange has spread above all in ibex populations in and around the Mediterranean Basin, where it is now found in almost a third of its host's range. Mite numbers varied seasonally and spatially and were higher in male hosts. The presence of S. scabiei had a negative effect on lice numbers but favoured the presence of ticks.

Sarcoptic mange in Felidae: does Sarcoptes scabiei var. felis exist? A first molecular study.

Domestic and wild felids are considered suitable hosts for the parasitic mite Sarcoptes scabiei, and sarcoptic mange is reported in several felid species in the scientific literature. However, the historic classification of Sarcoptes mites into host-specific varieties does not include S. scabiei var. felis. It is unclear whether sarcoptic mange transmission in felids involves canids, other sympatric species, or exclusively felids. This study aimed to characterize the genetic structure of S. scabiei mites from domestic cats (Felis catus) and Eurasian lynx (Lynx lynx carpathicus), comparing them with Sarcoptes mites from sympatric domestic and wild carnivores. Ten Sarcoptes microsatellite markers were used to genotype 81 mites obtained from skin scrapings of 36 carnivores: 4 domestic cats, one dog (Canis lupus familiaris), 4 Eurasian lynx, 23 red foxes (Vulpes vulpes), and 4 grey wolves (Canis lupus lupus) from either Italy, Switzerland or France. Two genetic clusters of S. scabiei with a geographical distribution pattern were detected: mites from cats originating from Central Italy clustered with those from sympatric wolves. In contrast, all the other mites from Switzerland, France and Northern Italy clustered together. These results strengthen the previously advanced hypothesis that genetic variants of S. scabiei have a predominant geographic-related distribution with cryptic transmission patterns. These patterns may rely on the interactions between different hosts living in the same ecological niche rather than a simple infection among hosts belonging to the same taxon, reinforcing the idea that the S. scabiei historic classification into "var" might have little ongoing relevance.

Title: La gale sarcoptique chez les félidés : Sarcoptes scabiei var. felis existe-t-il ? Première étude moléculaire. Abstract: Les félidés domestiques et sauvages sont considérés comme des hôtes appropriés pour l'acarien parasite Sarcoptes scabiei, et la gale sarcoptique est signalée chez plusieurs espèces de félidés dans la littérature scientifique. Cependant, la classification traditionnelle des acariens du genre Sarcoptes en variétés spécifiques à l'hôte n'inclut pas S. scabiei var. felis. On ne sait pas si la transmission de la gale sarcoptique chez les félidés implique des canidés, d'autres espèces sympatriques ou exclusivement des félidés. Cette étude visait à caractériser la structure génétique des acariens S. scabiei des chats domestiques (Felis catus) et du lynx eurasien (Lynx lynx carpathicus), en les comparant aux Sarcoptes des carnivores domestiques et sauvages sympatriques. Dix marqueurs microsatellites de Sarcoptes ont été utilisés pour génotyper 81 acariens issus de grattages cutanés de 36 carnivores : 4 chats domestiques, un chien (Canis lupus familiaris), 4 lynx eurasiens, 23 renards roux (Vulpes vulpes) et 4 loups gris (Canis lupus lupus) d'Italie, de Suisse ou de France. Deux groupes génétiques de S. scabiei, qui suivent un modèle de distribution géographique, ont été détectés. Les acariens des chats originaires du centre de l'Italie se regroupent avec ceux des loups sympatriques. En revanche, tous les autres acariens de Suisse, de France et d'Italie du Nord sont groupés ensemble. Ces résultats renforcent l'hypothèse précédemment avancée selon laquelle les variants génétiques de S. scabiei ont une distribution géographique prédominante avec des schémas de transmission cryptiques. Ces modèles peuvent reposer sur les interactions entre différents hôtes vivant dans la même niche écologique plutôt que sur une simple transmission parmi des hôtes appartenant au même taxon, renforçant l'idée que la classification historique de S. scabiei en "var" a peu de pertinence.

Main mites associated with dermatopathies present in dogs and other members of the Canidae family.

Dermatological diseases of parasitic origin are one of the most frequent in the clinical practice of dogs and cats. Mites such as Sarcoptes scabiei, Otodectes cynotis, Demodex canis, and Cheyletiella spp., commonly affect domestic dogs. However, the impact generated by these mites on populations of wildlife animals and the mechanisms involved in their epidemiological dynamics are still not clear. In recent decades, the migration of populations and their interaction with domestic environments and vice versa have generated a worrying threat due to the transmission of some of these ectoparasites. Some reports have suggested that sarcoptic mange represents an emerging threat to wildlife. Given the outbreaks of greater magnitude and geographical extension. The objective of this review is to contribute to the state of the art of the main mites that cause dermatopathies in members of the Canis lupus familiaris family and other members of the Canidae family. For this, a systematic search was carried out in the Embase and PubMed databases. Infections caused by mites, mainly scabies, continue to be diseases with a worldwide distribution, affecting mammals and humans. Although they are long-standing diseases, the effects that are generated in wild canids are still unknown. A comprehensive evaluation is required to generate guidelines in favor of the conservation of some species of foxes and wolves present in different regions of the world.

Essential Oils against Sarcoptes scabiei.

Herbal remedia are widely employed in folk medicine, and have been more and more often studied and considered in the treatment of several infections. Sarcoptic mange (scabies, when referring to human patients) is a highly contagious skin disease caused by Sarcoptes scabiei (sarcoptiformes, Sarcoptinae), an astigmatid mite which burrows into the epidermis, actively penetrating the stratum corneum. This parasitosis negatively affects livestock productions and represents a constraint on animal and human health. The treatment relies on permethrine and ivermectine but, since these molecules do not have ovicidal action, more than a single dose should be administered. Toxicity, the possible onset of parasite resistance, the presence of residues in meat and other animal products and environmental contamination are the major constraints. These shortcomings could be reduced by the use of plant extracts that have been in vitro or in vivo checked against these mites, sometimes with promising results. The aim of the present study was to review the literature dealing with the treatment of both scabies and sarcoptic mange by plant-derived agents, notably essential oils.

Effects of Sarcoptes scabiei Translationally Controlled Tumor Protein (TCTP) on Histamine Release and Degranulation of KU812 Cells.

Scabies is a common parasitic dermatological infection worldwide that is often neglected. Scabies mites stimulate host inflammatory symptoms via secreted and excreted proteins, which induce basophil and mast cell degranulation and host histamine release. However, the mechanism of degranulation and histamine release is unclear. Moreover, the Sarcoptes scabiei translationally controlled tumor protein (TCTP) is predicted as an excreted protein, which may be involved in host inflammatory response regulation. First, we evaluated S. scabiei TCTP gene (SsTCTP) transcription in larvae, nymphs, and adults by qRT-PCR, and SsTCTP transcription was highest in larvae, followed by nymphs. Second, we found that the S. scabiei TCTP recombinant protein (rSsTCTP) promoted mice histamine release in vivo by Evans blue Miles assay. Therefore, to further explore the possible role of S. scabiei TCTP in host inflammatory response regulation, we established a degranulation model of KU812 cells. The results of the degranulation model suggested that rSsTCTP could induce enhanced degranulation of KU812 cells and increase the secretion of histamine and the expression of IL-4, IL-6, and IL-13 in vitro. In conclusion, we speculate that scabies mites could stimulate host histamine release and Th2 response by excreting S. scabiei TCTP.

The genetic characteristics of Sarcoptes scabiei from Chinese serow (Capricornis milneedwardsii) and goral (Naemorhedus goral arnouxianus) compared with other mites from different hosts and geographic locations using ITS2 and cox1 sequences.

Scabies is a common parasitic disease in many mammalian species, caused by the infestation of Sarcoptes scabiei. There is no consistent conclusion on whether Sarcoptes mites from different hosts or geographic locations have apparent genetic divergence. In this study, we collected and morphologically identified S. scabiei from Chinese serow and goral, and we described the genetic diversity of S. scabiei and other mites based on phylogenetic analyses of the ITS2 and cox1 sequence fragments, including data available in GenBank. The mites isolated from Chinese serow and goral were S. scabiei, and they were morphologically similar. The phylogenetic trees and haplotype networks showed that S. scabiei from other locations worldwide did not cluster according to host divergence or geographical distribution. Additionally, the Fst values were - 0.224 to 0.136 and - 0.045 to 1 between S. scabiei from different hosts, including humans and domestic and wild animals, based on partial ITS and cox1 sequences. Worldwide S. scabiei samples formed three clusters (with H2, H5, and H12 at their centers) in the ITS and one cluster (with C9 at the center) in the cox1 haplotype phylogenetic network. The S. scabiei collected from Chinese serow and goral were morphologically similar and had the same genotype. A study on the genetic characteristics of S. scabiei from Chinese serow and goral together with other mites from different hosts and geographic locations around the world showed no obvious divergence. These findings indicated that scabies likely is a zoonotic disease and that the global prevalence of scabies is probably related to the worldwide trade of domestic animals.

Evidence that Transcriptional Alterations in Sarcoptes scabiei Are under Tight Post-Transcriptional (microRNA) Control.

Here, we explored transcriptomic differences among early egg (Ee), late egg (Le) and adult female (Af) stages of the scabies mite, Sarcoptes scabiei, using an integrative bioinformatic approach. We recorded a high, negative correlation between miRNAs and genes with decreased mRNA transcription between the developmental stages, indicating substantial post-transcriptional repression; we also showed a positive correlation between miRNAs and genes with increased mRNA transcription, suggesting indirect post-transcriptional regulation. The alterations in mRNA transcription between the egg and adult female stages of S. scabiei were inferred to be linked to metabolism (including carbohydrate and lipid degradation, amino acid and energy metabolism), environmental information processing (e.g., signal transduction and signalling molecules), genetic information processing (e.g., transcription and translation) and/or organismal systems. Taken together, these results provide insight into the transcription of this socioeconomically important parasitic mite, with a particular focus on the egg stage. This work encourages further, detailed laboratory studies of miRNA regulation across all developmental stages of S. scabiei and might assist in discovering new intervention targets in the egg stage of S. scabiei.

Sarcoptic mange changes bacterial and fungal microbiota of bare-nosed wombats (Vombatus ursinus).

BACKGROUND: Sarcoptes scabiei is globally distributed and one of the most impactful mammalian ectoparasites. Sarcoptic mange, caused by infection with S. scabiei, causes disruption of the epidermis and its bacterial microbiota, but its effects on host fungal microbiota and on the microbiota of marsupials in general have not been studied. Here, we (i) examine bacterial and fungal microbiota changes associated with mange in wild bare-nosed wombats (BNWs) and (ii) evaluate whether opportunistic pathogens are potentiated by S. scabiei infection in this species. METHODS: Using Amplicon Sequencing of the 16S rRNA and ITS2 rDNA genes, we detected skin microbiota changes of the bare-nosed wombat (Vombatus ursinus). We compared the alpha and beta diversity among healthy, moderate, and severe disease states using ANOVA and PERMANOVA with nesting. Lastly, we identified taxa that differed between disease states using analysis of composition of microbes (ANCOM) testing. RESULTS: We detected significant changes in the microbial communities and diversity with mange in BNWs. Severely affected BNWs had lower amplicon sequence variant (ASV) richness compared to that of healthy individuals, and the microbial communities were significantly different between disease states with higher relative abundance of potentially pathogenic microbial taxa in mange-affected BNWs including Staphylococcus sciuri, Corynebacterium spp., Brevibacterium spp., Brachybacterium spp., and Pseudogymnascus spp. and Debaryomyces spp. CONCLUSION: This study represents the first investigation of microbial changes in association with sarcoptic mange in a marsupial host, as well as the first investigation of fungal microbial changes on the skin of any host suffering from sarcoptic mange. Our results are broadly consistent with bacterial microbiota changes observed in humans, pigs, canids, and Iberian ibex, suggesting the epidermal microbial impacts of mange may be generalisable across host species. We recommend that future studies investigating skin microbiota changes include both bacterial and fungal data to gain a more complete picture of the effects of sarcoptic mange.

Evidence underscoring immunological and clinical pathological changes associated with Sarcoptes scabiei infection: synthesis and meta-analysis.

BACKGROUND: Sarcoptes scabiei is one of the most impactful mammalian parasites. There has been much research on immunological and clinical pathological changes associated with S. scabiei parasitism across a range of host species. This rich body of literature is complex, and we seek to bring that complexity together in this study. We first (1) synthesise narrative reviews of immunopathological relationships to S. scabiei infection to construct overarching hypotheses; then (2) undertake a systematic meta-analysis of primary literature on immunological and clinical pathological changes; and lastly (3) contrast our findings from the meta-analysis to our synthesis from narrative reviews. METHODS: We synthesised 55 narrative reviews into two overarching hypotheses representing type I and type IV immune responses to S. scabiei infection. We then systematically extracted all literature reporting immunological variables, acute phase proteins, oxidant/antioxidant status, and erythrocytic, hepatological and nephrological changes, calculating 565 effect sizes between controls and sarcoptic mange affected groupings, refining (simplifying) hypotheses from narrative reviews. RESULTS: Immunological and clinical pathological parameters were most often studied in dogs (n = 12) and humans (n = 14). Combining immunological and clinical pathological information across mammalian species (n = 19) helped yield general insights into observed disease responses. This is evidenced by interspecific consensus in 27 immunological and clinical pathology variables (6/26 type I hypersensitivity, 3/20 type IV hypersensitivity, 6/10 oxidant/antioxidant status, 3/6 acute phase protein, 4/7 erythrocytic, and 5/10 hepatological/nephrological). CONCLUSIONS: Elevated IgE, eosinophils and mast cells in type I hypersensitivity response corresponded to what was described in narrative reviews. Results from type IV hypersensitivity response suggested typical antibody response, however cell-mediated response was less evident. Some consensus of acute phase protein response and shifted oxidant/antioxidant balance and slight evidence of anemia. We highlight the need for mange/scabies studies to more routinely compare immunological and clinical pathological changes against controls, and include collection of a more standardised suite of variables among studies.

Can we increase the success of scabies treatment? The effect of removing tunnels from patients in the success of scabies treatment.

Recently, there has been an increase in scabies infestations. Moreover, the number of patients who do not benefit from conventional treatment regimens is increasing rapidly worldwide. This situation leads clinicians to seek new treatments. To evaluate the contribution of mechanical parasite removal to treatment success when applied prior to topical permethrin 5% treatment. The mechanical removal process was applied once during diagnosis. Two groups of 30 people each were included in the study. Permethrin treatment was given directly to the first group without any procedure. In the second group, the maximum number of tunnels that could be detected were removed from patients. After this procedure, the group received permethrin treatment. All patients were called for control after 10 days, and treatment response rates were evaluated. Sixteen (53.3%) patients who received permethrin treatment directly without any procedure responded to the treatment. In the remaining 14 (46.6%) patients, tunnels and Sarcoptes mites were still present. In the second group, which underwent tunnel removal, complete recovery was observed in 26 (86.6%) patients. The patients who did not benefit from the treatment in the study group had relatively less tunnel removal from their bodies. Removing the tunnel from the patient before the treatment increases the success of the treatment. Considering that there are 8-10 parasites on average in scabies patients, it has been determined that the tunnel removal method is not difficult and contributes to therapeutic success.

Spinosad topical suspension (0.9%): a new topical treatment for scabies.

INTRODUCTION: Scabies is a highly contagious skin disease caused by the parasitic mite Sarcoptes scabiei. There is no vaccine and for the past 30 years, the first line treatments have been topical permethrin and oral ivermectin. These drugs target mainly the parasite nervous system, killing only the motile stages. As they lack ovicidal activities, repeat treatments are required to achieve complete cure. Incompliance to repeat treatments causing prolonged drug usage has contributed to emerging drug resistances. In addition, they are not appropriate for all patient categories, specifically for infants and young children or pregnant and breast feeding women. Consequently, new single-dose scabicides are urgently needed. AREAS COVERED: In 2021, spinosad, a drug previously used to treat head lice, was approved by the US FDA as a topical scabies treatment. Here the pharmacology, clinical efficacy, and tolerability of this drug are discussed. EXPERT OPINION: As the first single-dose scabicide, the formulated 0.9% topical Spinosad solution shows significant efficacy, little systemic absorption, and no serious adverse reactions, making it a promising treatment for classical scabies in patients older than four years.

Immune mechanisms in human Sarcoptes scabiei (Acari: Sarcoptidae) infestations.

Scabies is a parasitic infestation of human and animal skin caused by different strains of the itch mite, Sarcoptes scabiei. The World Health Organization (WHO) has declared scabies in human as a neglected tropical disease, and today over 200 million people worldwide are affected. The two most commonly reported clinical manifestation of the condition are ordinary (OS) and crusted scabies (CS). CS, which can lead to fatal consequences due to secondary bacterial infections, is mostly observed in immunocompromised subjects but can also, although rarely, be detected in immunocompetent individuals. Innate and adaptive immune system components are involved in protection and pathogenesis of scabies, although with some differences between OS and CS. While the cutaneous immune response is dominated by CD4+ T-cells in OS, it is mainly mediated by CD8+ T-cells in CS. The two clinical conditions also differ in CD4+ T-cell-mediated immune responses with mixed TH 1/TH 2 (protective) and TH 2/TH 17 (non-protective) immunoprofiles in OS and CS, respectively. Moreover, the development of CS is associated with early immunosuppression that is followed by deleterious immune response to uncontrolled mite proliferation. However, the immune response to scabies still needs further attention due to inconsistent results in the literature. The aim of this study is to attract more attention to this area by summarizing the current literature on innate and adaptive immune responses triggered against S. scabiei mites.

Activity of terpenes derived from essential oils against Sarcoptes scabiei eggs.

BACKGROUND: The limited ovicidal activity of currently available acaricides is a significant obstacle to efficacious scabies treatment. Several essential oils or their respective components have proved to be active against the eggs of arthropods, mainly lice and ticks. Information on the activity of these oils and/or components against the eggs of mites remains very limited. The aim of this study was to assess the activity of six terpenes (carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool) commonly found in essential oils against the eggs of Sarcoptes scabiei. METHODS: Sarcoptes eggs were exposed to paraffin oil containing 1, 2.5, or 5% of each terpene tested. After a 12-h exposure period, the eggs were washed and placed in paraffin oil for hatching. Embryonic development following treatment was assessed every day to determine the stage of developmental arrest. RESULTS: The median effective concentration to obtain 50% egg mortality (EC50) was 0.5, 0.9, 2.0, 4.8, 5.1 and 9.8% for carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool, respectively. The microscopic images of eggs after each treatment indicated that these six terpenes may act by penetrating through the aeropyles on the egg surface. CONCLUSIONS: In conclusion, carvacrol, eugenol and geraniol possess significant ovicidal activities, which should be considered as promising ovicidal agents for the treatment of scabies.