Description of Babesia galileei sp. nov. A Piroplasmid species causing severe disease in domestic cats.

BACKGROUND: Babesiosis is a tick-borne infection caused by piroplasmid protozoa and associated with anemia and severe disease in humans, domestic animals and wildlife. Domestic cats are infected by at least six Babesia spp. that cause clinical disease. METHODS: Infection with a piroplasmid species was detected by microscopy of stained blood smears in three sick cats from Israel. Genetic characterization of the piroplasmid was performed by PCR amplification of the 18S rRNA, cytochorme B (CytB) and heat shock protein 70 (HSP70) genes and the internal transcribed spacer (ITS) locus, DNA sequencing and phylogenetic analysis. In addition, Haemaphysalis adleri ticks collected from two cats were analyzed by PCR for piroplasmids. RESULTS: The infected cats presented with anemia and thrombocytopenia (3/3), fever (2/3) and icterus (1/3). Comparison of gene and loci sequences found 99-100% identity between sequences amplified from different cats and ticks. Constructed phylogenetic trees and DNA sequence comparisons demonstrated a previously undescribed Babesia sp. belonging to the Babesia sensu stricto (clade X). The piroplasm forms detected included pear-shaped merozoite and round-to-oval trophozoite stages with average sizes larger than those of Babesia felis, B. leo and B. lengau and smaller than canine Babesia s.s. spp. Four of 11 H. adleri adult ticks analyzed from cat # 3 were PCR positive for Babesia sp. with a DNA sequence identical to that found in the cats. Of these, two ticks were PCR positive in their salivary glands, suggesting that the parasite reached these glands and could possibly be transmitted by H. adleri. CONCLUSIONS: This study describes genetic and morphological findings of a new Babesia sp. which we propose to name Babesia galileei sp. nov. after the Galilee region in northern Israel where two of the infected cats originated from. The salivary gland PCR suggests that this Babesia sp. may be transmitted by H. adleri. However, incriminating this tick sp. as the vector of B. galilee sp. nov. would require further studies.

Clinical practice guidelines for the diagnosis and treatment of scabies.

Scabies, caused by the Sarcoptes scabiei var hominis mite burrowing into the skin, is a highly contagious disease characterized by intense nocturnal itching. Its global impact is considerable, affecting more than 200 million individuals annually and posing significant challenges to healthcare systems worldwide. Transmission occurs primarily through direct skin-to-skin contact, contributing to its widespread prevalence and emergence as a substantial public health concern affecting large populations. This review presents consensus-based clinical practice guidelines for diagnosing and managing scabies, developed through the fuzzy Delphi method by dermatology, parasitology, pediatrics, pharmacology, and public health experts. The presence of burrows containing adult female mites, their eggs, and excreta is the diagnostic hallmark of scabies. Definitive diagnosis typically involves direct microscopic examination of skin scrapings obtained from these burrows, although dermoscopy has become a diagnostic tool in clinical practice. Treatment modalities encompass topical agents, such as permethrin, balsam of Peru, precipitated sulfur, and benzyl benzoate. In cases where topical therapy proves inadequate or in instances of crusted scabies, oral ivermectin is recommended as a systemic treatment option. This comprehensive approach addresses the diagnostic and therapeutic challenges associated with scabies, optimizing patient care, and management outcomes.

Redescription of adults and first description of the larva of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae), parasite of carnivorans in Western Asia.

The adults of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae) are redescribed and the larva of this species is described for the first time here. The adults of H. adleri that we studied were collected from various canid, felid and hyaenid carnivorans (Carnivora: Canidae, Felidae, Hyaenidae) as well as a hedgehog (Erinaceomorpha: Erinaceidae) in Iraq, Israel and West Bank. The males, females and larvae of H. adleri can be differentiated from Haemaphysalis (Rhipistoma) species occurring in the Palearctic portion of West Asia and Egypt as well those in the H. asiatica subgroup by the length of idiosomal setae, development and size of spurs on palpi, dental formula on the hypostome and size of spur on coxae. A lectotype of H. adleri has been designated and the geographic distribution and hosts of this tick species are discussed.

Pediculicide regulations and usage trends in Türkiye in 2015-2022.

BACKGROUND: Over the years, the increasing prevalence of head lice infestation has led to an increase in treatment-related costs and the development of resistance to pediculicides. This study aimed to evaluate pediculicide sales over an 8-year period (2015-2022), including the COVID-19 pandemic. METHODS: Data on products registered in the Turkish Pharmaceutical Index Dataview, Intercontinental Medical Statistics (IMS) database, sold on prescription and approved by the Ministry of Health in Türkiye were formally requested from the research organization IQVIA for pharmacologically active pediculicides (PAP) such as permethrin, pyrethrin, and sumithrin. Data for physically active products containing dimethicone (DMT) were obtained from the relevant pharmaceutical companies. Sale revenues were determined based on sale prices in the aforementioned year. RESULTS: Total sales of pediculicides decreased from 2,452,846 units in 2015 to 2,028,840 units in 2022. While PAP consumption decreased over the years, from 1,832,006 to 518,460 units, DMT consumption increased from 620,840 to 1,510,380 units, from 2015 to 2022. The total price of pediculicides for the consumer increased more than threefold in Turkish currency. In terms of USD, an almost similar amount of money was spent over the years, with the exception of 2022 when the expenditure almost halved mainly due to the high inflation rate in the country. CONCLUSION: The decrease in PAP and the increase in DMT indicate that local lice have developed resistance to the former. Further studies are needed to determine the possible development of resistance in the country.

Scientometric Evaluation of the Itch Mite, Sarcoptes scabiei (Acari: Sarcoptidae): The Last Four Decades of Global Academic Output on Scabies.

OBJECTIVE: Scabiosis, the infestation of the skin with Sarcoptes scabiei, is a neglected tropical disease, with at least 200 million people being infested with the parasite at any time. It is estimated that scabies is responsible for 0.07% of the total burden of disease worldwide. Objective of this study is to perform a scientometric analysis of S. scabiei literature using the Web of Science Core Collection database for the years 1981-2020. METHODS: All documents indexed between 1981 and 2020 in scabies literature were analyzed by using a search string including keywords of "scabies", "Sarcoptes scabiei" and "S. scabiei" in Web of Science Core Collection database. We excluded all materials including data on the bacterium species named Streptomyces scabies and Streptomyces scabiei. RESULTS: Overall, 2,933 articles were retrieved on scabies, 66.3% of which were original article. With 663 publications the USA was the most productive country, while The International Journal of Dermatology was the journal with the highest number of publications on scabies. Half of the most productive institutions and seven of the top ten prolific authors were also from Australia. The National Health and Medical Research Council of Australia was the most supportive funding agency. With 4,706 citations, 2020 was the year with most references on scabies. The most cited publication was "The Global Burden of Skin Disease in 2010: An Analysis of the Prevalence and Impact of Skin Conditions" by Hay et al. in the Journal of Investigative Dermatology with a total of 565 citations. The most collaborative country was Australia and the most cooperative institution was the University of Melbourne. CONCLUSION: The majority of the studies were done in a given country while multicenter studies are very rare. It is recommended that more studies should be conducted on scabiosis in developing countries where the problem of scabies is the biggest.

Pathogens in ticks collected in Israel: II. Bacteria and protozoa found in Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus.

Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus are very prevalent in Israel and are known to be vectors of human and animal diseases. The aim of this study was to identify the pathogens found in questing ticks and such parasitizing domestic and wild animals. Ticks were collected from 16 localities in Israel with the flagging technique and by examining dogs, hedgehogs, a badger and a tortoise. Bacterial and protozoal pathogens were analyzed by PCR and sequencing. Overall, 374 R. sanguineus s.l. specimens were collected, out of which 142 by flagging and 132 from six dogs. Rickettsia africae, Rickettsia massiliae, Rickettsia conorii subsp. israelensis, and Anaplasma sp. were identified in ticks collected by flagging, Rickettsia aeschlimannii was found only in specimens collected from dogs, while Ehrlichia sp., Coxiella burnetii, Hepatozoon canis and Leishmania infantum were recorded in ticks collected by flagging and from dogs. Out of 226 specimens of R. turanicus, 124 were collected by flagging, while additional 33 from eight dogs, 64 from seven southern white-breasted hedgehogs (Erinaceus concolor), two from a European badger (Meles meles) and one from a Greek tortoise (Testudo graeca). Out of 65 R. sanguineus s.l. pools 17 (26.2%) had pathogens, while seven of them were positive for one pathogen, and 10 for two pathogens. In 43 R. turanicus pools, R. aeschlimannii R. africae, Rickettsia barbariae, R. massiliae, Anaplasma sp., Ehrlichia sp. and C. burnetii, as well as Babesia microti, B. vogeli, Hepatozoon felis, and L. infantum was detected, while Listeria monocytogenes, Bartonella sp. and Toxoplasma gondii were negative in all R. sanguineus s.l. and R. turanicus pools examined. In conclusion, Babesia microti is reported for the first time in Israel, R. africae, R. aeschlimannii, C. burnetii and L. infantum are reported for the first time in R. sanguineus s.l. and R. turanicus, while H. felis is reported for the first time from R. turanicus in the country.

Head louse infestations before and during the COVID-19 epidemic in Israel.

Head louse infestations caused by Pediculus humanus capitis (Phthiraptera: Pediculidae) are a public health problem in developing and developed countries worldwide. Head to head contact is by far the most common mode of lice transmission. In March 2020, WHO declared the COVID-19 outbreak as a pandemic. Starting from March 2020, the Israeli government established mandatory isolation for extensive periods including closure of school systems for very long time. The aim of the project was to compare the pediculicide sale numbers before the COVID-19 epidemic with those starting of the epidemic in 2020, as a possible marker for changing epidemiology of head lice during the COVID pandemic. Data were collected from a large pharmacy chain in Israel, which provided the actual sales of pediculicides during the years 2010-2020. During the period 2010-2019 a significant increase of pediculicide sales from 281,986 - 498,107 was observed, the highest number being from 2019. In 2020, this number dropped to 294,477, a significant drop compared to previous years and to 2019. The results of this study suggest that head louse infestations are increasing in the last years, while the extended isolation of children due to COVID-19 influenced significantly the infestation rate of children with head lice.

Reestablishment of Rhipicephalus secundus Feldman-Muhsam, 1952 (Acari: Ixodidae).

Rhipicephalus secundus is reestablished as a valid tick name within the Rhipicephalus sanguineus group and removed from the synonymy list of Rhipicephalus turanicus. Morphological re-description of both male and female of R. secundus and the analysis of its phylogenetic position based on mitochondrial DNA sequences are presented. The morphological re-description was made with tick specimens collected on goat in Israel. The phylogenetic analyses showed that R. secundus belong to a different clade from those formed by R. turanicus sensu stricto (s.s.) and R sanguineus s.s., and by other taxa from the R. sanguineus group. Rhipicephalus secundus is morphologically related to R. turanicus, but the scutal punctation pattern of both male and female allows the morphological differentiation between R. secundus and R. turanicus, punctations being clearly more numerous and larger in the latter. Both male and female of R. secundus can be differentiated from those of R. sanguineus s.s. by the shape of the spiracular plate. In males, the dorsal prolongation of the spiracular plate is equal to the breadth of the adjacent festoon in R. secundus, while it is narrower than the breadth of the adjacent festoon in R. sanguineus s.s. The dorsal prolongation of the spiracular plate in the female of R. secundus is wider than in the female of R. sanguineus s.s. The genital apertures of the females of R. secundus and R. sanguineus are both U-shaped, but in R. sanguineus s.s. it is broader than in R. secundus. Considering the results obtained in this study, it can be stated that R. secundus is present at least in Israel, Palestinian Territories, Turkey, Albania and southern Italy, but it is necessary to carry out additional studies to determine the geographical range and host usage of this species.

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.

Pathogens in ticks collected in Israel: I. Bacteria and protozoa in Hyalomma aegyptium and Hyalomma dromedarii collected from tortoises and camels.

Ticks were collected from 30 Greek tortoise (Testudo graeca), and 10 Arabian camels (dromedary) (Camelus dromedarius) in Israel. All those collected from Greek tortoises belonged to Hyalomma aegyptium, while all specimens collected from the camels belonged to Hyalomma dromedarii. Out of 84 specimens of H. aegyptium, 31 pools were examined by PCR, while from 75 H. dromedarii specimens nine pools were studied. Out of 31 pools of H. aegyptium 26 were positive for pathogens or endosymbiont; 14 for one, 11 for two and one for three pathogens. Out of nine pools prepared from H. dromedarii, seven were positive for pathogens (two for C. burnetii and five for Leishmania infantum). In H. aegyptium, Rickettsia africae, Rickettsia aeschlimannii, Rickettsia endosymbiont, Coxiella burnetii, Hemolivia mauritanica, Babesia microti, Theileria sp., and Leishmania infantum was detected, while in H. dromedarii C. burnetii and L. infantum were found. None of the ticks were positive for Anaplasma/Ehrlichia, Listeria monocytogenes, Bartonella spp., Hepatozoon spp. and Toxoplasma gondii. H Rickettsia endosymbionts, C. burnetii, B. microti, Theileria sp. and L. infantum are reported for the first time in H. aegyptium, and C. burnetii and L. infantum for the first time in H. dromedarii.

Protozoan and Microbial Pathogens of House Cats in the Province of Tekirdag in Western Turkey.

Domestic felines' re-emerging infectious and neglected zoonotic diseases are a significant focus of global "One Health" efforts. This study aimed to rapidly diagnose 14 pathogens, including zoonoses by using PCR primers in 167 client-owned symptomatic cats, routinely accepted to the Veterinary Clinics of Tekirdag. The prevalence of pathogens investigated were as follows: Babesia canis canis (24%), Babesia microti (2.4%), Hepatozoon felis (10.8%), Cytauxzoon felis (6.6%), Bartonella henselae (40.1%), Anaplasma platys (30.5%), Anaplasma phagocytophilum (7.2%), Rickettsia felis (26.3%), Borrelia burgdorferi (21%), and hemotropic Mycoplasma sp. (11.4%). There was a significant difference between the prevalence of the pathogens (χ2 = 152.26, df = 9, p < 0.001). There was also a statistical difference between the gender of the cats in terms of the prevalence of all pathogens considered together (χ2 = 4.80, df = 1, p = 0.028), where the female cats showed a higher prevalence. This was not the case for the different age groups (χ2 = 2.92, df = 1, p = 0.088). The lowest infection was observed for B. microti (p < 0.001), while the highest infection was observed for B. henselae (p < 0.01). Leishmania donovani, Plasmodium spp., Ehrlichia chaffeensis, and Neoehrlichia mikurensis PCR test results were negative in all samples. In conclusion, house cats of Tekirdag are apparently highly susceptible to some neglected zoonoses important for "One Health", and their prevalence in the region is most probably underestimated. Hence, applying PCR tests to assist fast clinic diagnosis in routine, may be an efficient option to protect the public as well as the cats from severe diseases.

International recommendations for an effective control of head louse infestations.

Head louse infestations continue to be a concern of public health in most countries, including the most developed ones. The present recommendations are intended to inform and stress the role and impact of the different authorities, institutions, industry, and the public in the control of head lice in order to reduce the prevalence of this parasite. We encourage health authorities to pursue more effective methods to correctly identify such infestations, and evaluate existing and new pediculicides, medical devices, louse repellents, and louse- and nit-removal remedies. Pediculicides and medical devices must have verifiable claims in the instructions for use and should be tested periodically to document current levels of resistance by lice to the active ingredients and to the formulated products. Where the prevalence of lice is claimed to be epidemic, children should be periodically evaluated objectively to document the actual level of prevalence. Continuing education for health providers and the general population promises to correct misinformation regarding the biology, prevention, and management of lice. Parents should regularly inspect their children for head lice and treat as necessary. Health authorities are encouraged to eliminate policies and practices that rely upon school exclusion as a means to reduce incidence and prevalence, e.g., the 'no-nit' policy which lacks scientific justification, and are counterproductive to the health and welfare of children.

Integrative taxonomy and species delimitation of Rhipicephalus turanicus (Acari: Ixodida: Ixodidae).

Rhipicephalus turanicus ticks are widely distributed across the Palearctic and Afrotropics. These two continental populations display differences in morphological characters that raise the question of a potential species boundary. However, the taxonomic status of these morphologically divergent lineages is uncertain because R. turanicus from Cyprus and Zambia have been shown to interbreed and produce fertile hybrids. We employ integrative taxonomy that considers data from mtDNA sequences (12S and 16S rDNA), geographic distribution, traditional (qualitative) morphology, as well as shape outlines of female spiracles and male adanal plates measured in a geometric morphometric framework (quantitative morphology) to resolve this taxonomic issue. Molecular lines of evidence (12S and 16S rDNA) support taxonomic separation between ticks sampled in the Afrotropics and the Palearctic. This is corroborated by qualitative and quantitative morphology. Within the Palearctic, two sub-lineages were recovered based on sequence data that loosely correspond to southern Europe and the Middle East/Asia. One new species, Rhipicephalus afranicus n. sp. is described from South Africa with a geographic distribution that extends into eastern Africa. This leaves R. turanicus sensu lato comprised of two lineages located in southern Europe and the Middle East/Asia. The type locality for R. turanicus is in Uzbekistan, thus the Middle East/Asia lineage is considered R. turanicus sensu stricto. Detailed descriptions are provided for R. afranicus n. sp. and R. turanicus sensu stricto together with high resolution images. Speciation is attributed to recent Sahara desert expansion that formed a natural barrier to dispersal approximately 5-7 million years ago. However, reproductive potential between these two species suggests that divergence time and mode of speciation were not sufficient for the development of reproductive isolation. We suggest speciation was complicated by divergence and population reintegration events driven by oscillating climatic conditions contributing to reticulate evolution and maintenance of compatibility between reproductive mechanisms. This study represents an integrative (iterative) approach to delimiting Rhipicephalus spp., and provides the first application of shape outlines for female spiracles and male adanal plates measured in a geometric morphometric framework, applied to testing species boundaries between ticks.

Bacterial and protozoan agents found in Hyalomma aegyptium (L., 1758) (Ixodida: Ixodidae) collected from Testudo graeca L., 1758 (Reptilia: Testudines) in Corum Province of Turkey.

Hyalomma aegyptium (L., 1758) (Ixodida: Ixodidae) is a hard tick and the main host for adults are Palearctic tortoises of the genus Testudo, while larvae and nymphs are less host-specific and nymphs also attach to humans. In the present study, a total of 261 H. aegyptium ticks were removed from 26 Testudo graeca L., 1758 in Corum Province of Turkey. The most prevalent pathogens identified molecularly in the ticks were Hemolivia mauritanica (51.9 %), followed by Rickettsia aeschlimannii (32.6 %), Ehrlichia spp. (30.2 %), and Bartonella bovis (0.8 %). All samples were negative for Coxiella burnetii, Francisella tularensis, Anaplasma phagocytophilum, Babesia spp., Hepatozoon spp. and Theileria spp. Overall, 97.4 % of the examined adult ticks and 26.3 % of nymphs were infected with at least one pathogen, while 40.9 % of all ticks were infected with only one pathogen, 27.4 % with two pathogens, and 9.9 % with three pathogens, concomitantly. Overall, 80.8 % of the examined blood smears of tortoises were H. mauritanica-positive, and the mean intensity of parasitemia was 4.8 % (1-21). As a conclusion, since the examined tortoises were sampled in gardens and vineyards close to human habitation, and as a relatively large percentage of them were infested with ticks carrying pathogenic agents affecting also humans, the importance of tortoises, their ticks and pathogens in terms of the public health should be farther examined.

Massive Orbital Myiasis Caused by Sarcophaga argyrostoma Complicating Eyelid Malignancy.

Purpose. To report a case of massive orbital myiasis caused by the larvae of Sarcophaga argyrostoma, complicating eyelid malignancy. Observations. A 98-year-old man first presented to our clinic noted to have a fast-growing lesion on his right upper and lower eyelids. Squamous cell carcinoma of the eyelids was highly suspected, and surgical excision was advised, but the patient refused any surgical or nonsurgical intervention. For the next eight months, the patient's family members continued to observe a high rate of tumor growth accompanied by deterioration of the general condition. During this whole period, the patient rejected admission to the hospital and was observed by nursing home staff. He was admitted to the emergency room in cachexic, unresponsive condition with fetid discharge and multiple live maggots crawling out from a large necrotic mass over the right orbit. On examination, no eyelids, eyeball, or other ocular tissue could be seen, while an extension of necrotic mass to forehead and midcheek was noted. Manual removal of larvae was performed. The patient passed away eight hours after his admission and larval removal. The maggots were identified as the third-instar larvae of Sarcophaga argyrostoma. Conclusions and Importance. This is the first reported case of home-acquired, massive orbital myiasis by S. argyrostoma. This case illustrates the crucial role of fly control as part of medical and home care in immobile patients. Moreover, it shows the importance of awareness by nursing home staff, paramedical, and medical personnel of possible myiasis, especially in bed-bound patients with skin malignancies and open wounds.

Polyplax brachyrrhyncha (Anoplura: Polyplacidae) and Rhipicephalus turanicus (Ixodidae: Rhipicephalinae) in an Ancient Louse Comb.

A fine-toothed comb found in the Judean Desert and resembling an ancient louse comb was examined. Based on radiocarbon dating, it ranged between 1660 AD and 1950 AD. From the material accumulated between the teeth, an oribatid mite, a pseudoscorpion, exuviae of beetle larvae, a sucking louse (Polyplax brachyrrhyncha Cummings, 1915), as well as a fully engorged larva and a nymph of the ixodid tick Rhipicephalus turanicus Pomerantzev, 1936 were recorded. Additionally, the comb included numerous hairs of a spiny mouse (Acomys sp.). Although finding mites, beetle larvae, and a pseudoscorpion on a louse comb could be regarded as contamination, the findings of P. brachyrrhyncha, as well as of a larva and nymph of R. turanicus, are noteworthy. We hypothesize that the presence of animal lice and ticks could indicate some sort of pet grooming.

Scientometric analysis of medicinal leech therapy.

BACKGROUND: Hirudotherapy, also known as medicinal leech therapy, has been used to treat a wide range of disorders for thousands of years since Ancient Egypt. Leech therapy is also mentioned as a minimal invasive technique called Jalaukavacharana in the Sushruta Samhita, an ancient Sanskrit text of Ayurvedic medicine. Although hirudotherapy has become a popular component of complementary medicine in the last decade, scientometric studies investigating the articles published in this field, do not exist. OBJECTIVE: In this study, we aimed to perform a detailed scientometric analysis of hirudotherapy literature. MATERIALS AND METHODS: We collected data by using four databases provided by Web of Science using the keywords "hirudotherapy", "leech therapy", "medicinal leech" and "medicinal leech therapy". RESULTS: A total of 834 articles were found of which 89.8% were original articles. USA was the leading country with 280 publications, followed by UK, Germany and France (128, 101 and 41 items, respectively). The most productive countries regarding hirudotherapy were the UK (1.93), Slovenia (1.44), and Israel (1.32). The peak publication year for hirudotherapy literature was 2011 with 41 papers. CONCLUSION: To the best of our knowledge, our study was the first bibliometric and scientometric analysis in this field and we believe that multicenter studies and further searches from developing and least-developed countries are needed in hirudotherapy literature.

Immune mechanisms in human and canine demodicosis: A review.

Demodex mites are saprophytic parasites of the mammalian skin, mostly found in or near pilosebaceous units of hairy regions. While they can be found in healthy humans and animals without causing any clinical manifestations, they were suggested to create pathogenic symptoms when they appear in high densities under favourable conditions (ie, demodicosis). Nevertheless, their role as the primary causative agent of the pathogenic conditions in humans is debated today. Canine demodicosis, which is highly prevalent in certain dog breeds, provides a valuable tool for studying the pathogenesis of human demodicosis. Canine and human demodicosis are caused by different Demodex species, and the clinical manifestations in former could be life-threatening. Nevertheless, current literature suggests similar immune responses and immune evasion mechanisms in human and canine demodicosis; cellular immunity appeared to have a central role in protection against demodicosis, and Demodex mites were shown to influence both innate and adaptive immune response to escape immune attack. The aim of this review is to summarize the relevant literature on demodicosis obtained from studies conducted on both organisms, and draw the attention to the effect of mite-associated factors (eg, microbiota) on the different clinical manifestations displayed during human and canine demodicosis.

Skin-homing T-cell responses associated with Demodex infestation and rosacea.

AIMS: Our aim was to investigate the skin-homing T-cell immune responses triggered in patients with Demodex infestation and/or rosacea. METHODS: Collected whole blood samples were divided into four groups: control subjects; nonrosacea patients with Demodex infestation (Demodex group); papulopustular rosacea (PPR) patients without Demodex infestation (Rosacea group); and PPR patients with Demodex infestation (Rosacea/Demodex group). Following ex vivo activation, skin-homing CLA+CD4+ T-cell subset levels were monitored by flow cytometry. RESULTS: When compared with control subjects, among skin-homing CD4+ T-cell subsets analysed, Demodex patients had higher TH 9 and Treg cell levels; Rosacea subjects displayed elevated TH 1 cell levels; and Rosacea/Demodex patients exhibited increased frequencies of TH 9 and TH 22 cells. In contrast to Rosacea subjects, Rosacea/Demodex group members displayed higher TH 2 cell levels; and when compared with Demodex groups, they had higher TH 1 and TH 2 but lower Treg cell levels. Demodex group members also exhibited higher Treg but lower TH 1 and TH 22 levels than Rosacea/Demodex group subjects. CONCLUSIONS: The skin-homing T-cell responses associated with Demodex infestation and rosacea formation seem to influence each other. The present as well as future studies could contribute to the development of effective treatment strategies for demodicosis and rosacea.