Demodex Species Research Articles

Identification and management of infections caused by Giardia sp., Trichuris sp. and Demodex sp. in captive Brazilian porcupines (Coendou prehensilis)

The Brazilian porcupine (Coendou prehensilis, Rodentia, Erethizontidae) is an arboreal South American nocturnal rodent. Switzerland is home to one of the largest captive colonies in Europe. In June 2022, most of the animals in this colony showed severe diarrhoea, and Giardia sp. cysts were detected. All the animals were treated with metronidazole (75 mg/animal/day orally) for five days, repeating after two weeks. The diarrhoea continued, sometimes containing blood, and further analyses revealed Giardia sp. cysts and Trichuris sp. eggs with a particular undulating eggshell in pooled samples. The soil layer of some enclosures was removed to thoroughly clean and disinfect the underlying concrete floor. The animals were treated with fenbendazole (50 mg/kg/day orally) for 5 days repeating after three days. Giardia sp. cysts were not further detected. However, Trichuris sp. eggs were detected in branch bark samples and in six animals 2–3 months after treatment. The treatment with fenbendazole was repeated and no further Trichuris sp. eggs were detected. A 18S rRNA fragment consensus sequence showed 98.58% identity with Trichuris fossor. The Trichuris sp. in C. prehensilis may represent a new species, specific for arboreal porcupines. Demodex mites were observed in faecal flotations and thereafter in skin scrapings from five animals (four of them being family-related). A 16S consensus sequence showed 86.4% identity with other Demodex species. The animals were initially treated with moxidectin (0.4 and 0.8 mg/kg orally) and afterwards with sarolaner (10 mg/animal) but the treatments were not completely effective since in control scrapings, two animals evidenced few non-motile mites. An individual susceptibility and poor immunological control of the infection is suggested. Treatment with fenbendazole was effective against Giardia sp. and Trichuris sp. infections; however, reinfections may occur if the enclosures and tree branches are not deep cleaned and disinfected or replaced.

Investigation of the in-vitro lethal effect of spilanthol on demodex and finding the most effective dose.

Demodex species are associated with many dermatological diseases, so an acaricidal agent that is effective against them and safe for skin applications may benefit many diseases. This study aims to investigate the anti-demodex potential of spilanthol, a product obtained from the Spilanthes Acmella plant, by determining the minimal effective dose for the first time in the literature. Demodex mites were obtained from 70 patients with standard superficial skin biopsy. Spilanthol extract was used at 1%, 2%, 3%, 4%, and 5%. Standard immersion oil was used for the negative control, and permethrin 5% was used for the positive control group. The dependent variable is the survival time of the mite. Comparisons with the negative control group, the anti-demodex effect demonstrated itself in all groups, creating a statistically significant difference (p < 0.001). The positive control group, had 3%, 4%, and 5% spilanthol rates which were very similar to the results with 5% permethrin (p > 0.05). Higher concentrations than 3% did not make any additional contribution to survival times. This is the first attempt to show the dose-dependent acaricidal effect of spilanthol on demodex mites. Even the 3% dose shows similar results to 5% permethrin, and no additional effect increase was observed at higher doses. Therefore, in vivo, studies may be planned with a 3% spilanthol dose for further studies.

Morphometry of Demodex species in dogs

The present study was carried out to record the mean length and width of gnathosoma, podosoma and opisthosoma of two different Demodex mites in dogs. The mean lengths gnathosoma, mean width of gnathosoma, podosoma and opisthosoma did not differ significantly (P&gt;0.05); mean length of podosoma, opisthosoma and the total body differed significantly (P&lt;0.05) between both types of mites of Demodex canis and Demodex cornei. The present study suggests that apart from examination of deep skin scrapings, tape impression smears may also be made a regular practice while dealing with demodicosis suspected dogs in order to detect the surface dweller like Demodex cornei

Which factors influence Demodex mite density in standardized superficial skin biopsy in patients with rosacea? A prospective cross-sectional analysis.

Rosacea is a chronic cutaneous disease that manifests with facial erythema, telangiectasia, papules and pustules on the central face. Although the pathogenesis is not well established, rosacea appears to have a close relationship with Demodex mites. The aim of the study was to elucidate the factors influencing Demodex mite density by standardized superficial skin biopsy (SSSB) in patients with rosacea. This prospective, cross-sectional study included 200 patients with rosacea. Clinical characteristics of the patients were recorded and SSSB was used to measure Demodex density (Dd). If Dd was < 5 D/cm2 in the first SSSB, SSSB was repeated 4 more times to avoid false negative results. Of 200 patients, 152 (76%) were females and 48 (24%) males with a mean age of 43.47 ± 11.87 years. Ninety-nine patients (49.5%) had erythematotelangiectatic (ETR) and 101 patients (50.5%) had papulopustular (PPR) subtype of rosacea. Among 200 patients, the ratio of cumulative positive results of the consecutive SSSBs were as follows: 1st SSSB = 125 (62.5%), 2nd SSSB = 155 (77.5%), 3rd SSSB = 170 (85%), 4th SSSB = 173 (86.5%) and 5th SSSB = 174 (87%). The ratio of detecting Demodex infestation in the first SSSB was significantly lower in patients with PPR (55/101, 54.5%) than in patients with ETR (70/99, 70.7%). Median total Demodex mite density and D. folliculorum density were significantly higher in the ETR group than in the PPR group. There was a statistically significant relationship between density of Demodex tails in dermoscopy and positive/negative results of Demodex infestation in SSSB. As a conclusion, Demodex mite density by SSSB was influenced by various factors such as subtypes of rosacea, types of Demodex species, and dermoscopic findings.

Human Demodex mites (Acari: Demodicidae) as a possible etiological factor in Rosacea: A cross-sectional study from Turkey

This study was conducted to determine the prevalence and burden of Demodex mites in patients with rosacea, and to investigate their potential contribution to the aetiology of rosacea. The study included 82 patients (44 with papulopustular rosacea and 38 with erythematotelangiectatic rosacea) diagnosed with rosacea by clinical examination and 82 healthy controls without dermatologic disease. Samples were obtained from each participant from the cheek, nasolabial, and chin regions using standardised skin surface biopsy (SSSB). Samples were examined under a light microscope, and Demodex species were identified and counted. Demodex positivity (≥5 mites) was detected in 91% of patients and 20% of controls in the study (p&lt; 0.01). Only D. folliculorum (total 1328, mean 44.27/cm2) was detected in 37% of patients and D. folliculorum + D. brevis coinfection (total 6071, mean 134.91/cm2) in 55% of patients. Only D. folliculorum (total 97, mean 6.06/cm2) was detected in 20% of healthy controls, while D. folliculorum + D. brevis co-infection was not detected. The study showed that Demodex burden in patients with rosacea was approximately 30 times higher than in healthy controls and was caused by coinfection of D. folliculorum and D. brevis (mean Demodex burden: 179.18/cm2 in patients, 6.06/cm2 in healthy controls). It was concluded that Demodex infestation, especially co-infection with D. folliculorum and D. brevis, may be a potential factor in the aetiology of rosacea that should not be ignored in the clinic, and that it may be appropriate to initiate antiparasitic treatment when the parasite is detected.

Demodicidosis in clinical practice: more questions than answers

Demodicosis is a common parasitic dermatosis in humans. Data on the role of demodicosis as an independent nosological form are contradictory. However, in ICD-10 demodicosis is encrypted as "B88. Other acariasis. Dermatitis due to Demodex species". Purpose. To study the variety of approaches of dermatologists to the problem of demodicosis using the anonymous survey method. Methods. An individual registration card was used for an anonymous survey of doctors, including 45 questions with various answer options, posted on the electronic resource Google forms https://forms.gle/neH4zn27znwv4ZrW7. Doctors received information about the study at the Department of Skin and Sexually Transmitted Diseases with a cosmetology course at the Medical Institute of Continuing Education of the Federal State Budgetary Educational Institution of Higher Education "ROSBIOTECH" and at the conference "Infections and Infection Control in Dermatology" (Moscow, 2023). 134 doctors took part in the study. Results. Data on the level of professional training of doctors is presented. Defined frequency of registration of demodicosis in clinical practice, diagnostic criteria for demodicosis as an independent nosological form, features of its course against the background of coronavirus infection. Disadvantages and difficulties in laboratory diagnostics have been identified. The spectrum, frequency of use of drugs for treatment and their off-label use have been studied. Conclusions. Entrenched false stereotypes regarding the clinic, diagnosis and treatment of the disease have been identified, which forms the basis of a scientific research algorithm to eliminate the identified shortcomings.

A new species of Demodex (Acari: Demodecidae) from the skin of golden-handed tamarins, Saguinus midas (Primates: Cebidae)

Two captive-bred golden-handed tamarins, Saguinus midas L., 1758 (Primates: Cebidae), kept in households in Japan, presented with psoriasis-like plaques on their faces, along with scale, alopecia, and itching. Histopathological examination revealed numerous Demodex mites in the hair follicles, and the clinical symptoms in both cases improved after treatment with fluralaner. Based on the morphological and genetic characteristics of the mites collected from tamarins, we describe a new species of Demodex. This new species is the fifth valid Demodex species recorded from primates.

Demodicosis in a Kunekune pig and molecular characterisation of porcine demodectic mites involved: a case report

BackgroundIn January 2021, a female 1-year-old Kunekune was presented at the University Clinic for Swine with severe reduction of the field of vision resulting in prolonged reaction time when targeting barriers, due to moderate to severe thickening of the skin around both orbits also affecting the eyelids. MethodsClinical examination revealed skin hyperplasia, nodular enlargement of the skin pores of the axillar and inguinal region. Ophthalmologists decided to remove parts of the thickened periocular skin, followed by histopathological examination.ResultsOnce large amounts of demodectic mites were detected by histopathology, demodicosis could be diagnosed and treatment of the pig was started using sarolaner. Morphological and molecular analyses were performed. Histopathological and parasitological exams led to the aetiological diagnosis of demodicosis in the affected Kunekune pig. Severe skin lesions were revealed to be the consequence of an infestation with Demodex sp. Morphological analyses confirmed the involvement of D. phylloides. Molecular characterization indicated a Demodex species closely related to mites documented in wild boar - most probably D. phylloides for which no explicit sequences are available in GenBank yet. Treatment with sarolaner (2.6 mg/kg) resulted in a substantial regression of skin lesions, already detectable 1 month after first treatment.ConclusionsDemodicosis is a very rare disease in pigs that is most probably related to an impaired immune response to the mites. Demodectic mange should be included in the list of differential diagnoses in cases of periocular alterations of the skin of pigs.Graphical

The Skin Microbiome and its Significance for Dermatologists.

The skin is a physical and immunological barrier to the external environment. Its large surface area is colonized by diverse communities of microorganisms, including bacteria, viruses, fungi, and Demodex species mites. These microorganisms and their genetic material together create the skin microbiome. Physiologic and anatomic properties of skin sites create biogeographical habitats (dry, moist, and sebaceous) where distinct microbiota communities reside. Although, in general, the composition of these habitats is maintained from person to person, the skin microbiome of an individual also has unique microbial features. Dysbiosis occurs when the normal abundance, composition, or location of the microbiota is changed, most notably there is a decrease in flora diversity. Certain skin diseases, including atopic dermatitis, rosacea, and psoriasis are associated with cutaneous dysbiosis, and even disruption of the gut microbiota. Studies have shown that current treatments for these dermatologic conditions can alter/stabilize the skin microbiome, and there is emerging research detailing the impact of prebiotics, probiotics, and postbiotics on these conditions. Although clinical guidelines do not currently exist, clinical studies support the safety and possible benefits of using topical prebiotics and postbiotics and oral probiotics for a variety of skin conditions. Until such guidelines exist, utilizing carefully designed clinical studies to inform clinical practice is recommended.

Alternative Treatments for the Cure of Dogs Infested by Demodex canis Leydig, 1859 (Arachnida: Acarina)

Demodicosis is a very common cutaneous parasitic disease that afflicts dogs, usually inflammatory, does not produce contagion and is related to the excessive proliferation of mites of different species of the genus Demodex, which are commensal hosts, in small quantities, in the skin of canids. The objective of the research work was to propose a series of alternative treatments for the cure of demodicosis in dogs, using traditional natural medicine. The diagnosis was made by direct observation of D. canis in multiple skin scrapings, trichogram, acetate tape test, skin biopsy among others. In addition, data collection and processing methods were used. A total of 25 dogs infested by D. caninus, with generalized demodicosis (12 males and 8 females) aged between 6 months and 12 years were studied. The SPSS statistical program was used for data processing. As a result of the application of alternative treatments, with the use of traditional natural medicine, it was found that 100% of the specimens of Canis familiaris Linnaeus, 1758, were cured in different periods, taking into consideration the severity of the lesions and their breed. It is considered that the use of alternative treatments can substitute the use of industrial pharmaceuticals.

Correlation between Demodex species in primary and recurrent chalazia

ObjectiveTo determine the correlation between the infestation by species of Demodex spp. and the occurrence of primary and recurrent chalazia. MethodsProspective and observational study. Patients with primary or recurrent chalazia were included. Eyelash samples were taken to determine the microscopic presence of Demodex spp. The correlation between the recurrence of the chalazia and the infestation by Demodex spp. mites was determined using Spearman’s rank correlation coefficient test. ResultsSixty-eight adult patients diagnosed with chalazia were included. In 63.2% of the total cases, the presence of one or more parasites of the genus Demodex spp. was documented. In the quantitative parasitological study, it was found that 25% of all cases presented infestation by Demodex spp. defined by an index greater than or equal to 0.5 parasites per eyelash. The most frequently found species was Demodex folliculorum. Of the 14 patients with recurrent chalazia, 50% presented infestation by Demodex spp. and in 91.7% of the cases the infestation was by D. folliculorum. There is a positive, directly proportional correlation between these factors (rθ=+0.665, P<.05). In the group of patients with primary chalazion, only 18.5% presented infestation by Demodex spp., and in 81.6% of these cases it was caused by D. folliculorum. There is a non-statistically significant correlation between these two factors. ConclusionThere is a direct, high and statistically significant correlation between the recurrence of the chalazion and the infestation by Demodex spp., there is no statistically significant correlation between the primary chalazia and the presence of Demodex spp.

Correlación entre especies del género Demodex en chalaziones primarios y recurrentes

ObjectiveTo determine the correlation between the infestation by species of Demodex spp. and the occurrence of primary and recurrent chalazia. MethodsProspective and observational study. Patients with primary or recurrent chalazia were included. Eyelash samples were taken to determine the microscopic presence of Demodex spp. The correlation between the recurrence of the chalazia and the infestation by Demodex spp. mites was determined using Spearman's rank correlation coefficient test. ResultsSixty-eight adult patients diagnosed with chalazia were included. In 63.2% of the total cases, the presence of one or more parasites of the genus Demodex spp. was documented. In the quantitative parasitological study, it was found that 25% of all cases presented infestation by Demodex spp. defined by an index greater than or equal to 0.5 parasites per eyelash. The most frequently found species was Demodex folliculorum. Of the 14 patients with recurrent chalazia, 50% presented infestation by Demodex spp. and in 91.7% of the cases the infestation was by D. folliculorum. There is a positive, directly proportional correlation between these factors (rθ=+0.665, P<.05). In the group of patients with primary chalazion, only 18.5% presented infestation by Demodex spp., and in 81.6% of these cases it was caused by D. folliculorum. There is a non-statistically significant correlation between these two factors. ConclusionThere is a direct, high and statistically significant correlation between the recurrence of the chalazion and the infestation by Demodex spp., there is no statistically significant correlation between the primary chalazia and the presence of Demodex spp.

Cloning, sequencing, expression, and purification of aspartic proteases isolated from two human Demodex species

Aspartic proteases (ASPs) are important hydrolases for parasitic invasion of host tissues or cells. This was the first study on Demodex ASP. First, the complete coding sequence (CDS) was amplified, cloned and sequenced. Then, the protein physical and chemical properties was analysed. Finally, the recombinant plasmid, expression and purification system was established. Results showed that the lengths of CDS of Demodex folliculorum and D. brevis were 1161 and 1173 bp, respectively. The molecular weight of the protein was approximately 40 KDa. It contained an aspartic acid residue, a substrate-binding site and signal peptide, yet lacked a transmembrane domain and was located in the membrane or extracellular matrix. The phylogenetic and conserved motif analyses showed that D. folliculorum and D. brevis clustered separately and then formed a single branch, which finally clustered with other Acariformes species. The prokaryotic expression systems for recombinant ASP with His-tag (rASP-His) and GST-tag (rASP-GST) were constructed. The inclusion bodies of rASP-His were renaturated by gradient urea and purified using NI beads, while those of rASP-GST were renaturated by sarkosyl and Triton X-100 and purified using GST beads. Conclusively, the prokaryotic expression and purification system of Demodex rASP was successfully established for further pathogenic mechanism research.

Demodex Species and Culturable Microorganism Co-Infestations in Patients with Blepharitis.

We aimed to determine the prevalence of Demodex spp. and bacterial infection in patients with blepharitis and also to investigate the relationship between culturable microorganisms and Demodex spp. in this study. The study included patients diagnosed with blepharitis (n = 128) and volunteers without ocular problems (n = 113). Eyelash sampling was performed by epilating eight lashes, which were then tested for Demodex spp. using a light microscope. The examination consisted of assessing the patient's vision with and without ocular correction and tonus in both eyes and a careful examination of the anterior segment of both eyes. Bacterial identification was performed based on morphological, physiological, and biochemical methods. The prevalence of Demodex spp. was 8.0% in patients from the control group and all patients with blepharitis. Isolated forms of Demodex spp. were detected in all infested patients in the control group and in 58% of patients with blepharitis. A total of 35% of patients with blepharitis had from three to nine forms of Demodex spp., and 7% of patients with blepharitis had more than 10 mites in every field of vision. We found a statistically significant relationship between Demodex spp. infestation and the occurrence of eye dryness and sensations of burning and tearing, redness of the conjunctiva, feeling of a foreign body, loss of eyelashes, Meibomian gland dysfunction, and cylindrical dandruff. There were statistically significant relationships between Demodex sp. infestation and the presence of hyperopia, Meibomian cysts, chronic eyelid inflammation, and the use of eyeglasses. There was also a statistically significant relationship between the occurrence of Demodex spp. and seborrheic dermatitis and diabetes mellitus. Culturable microorganisms of the ocular surface were found in 8.7% of participants who were uninfested and in all patients infested with D. folliculorum. We isolated Staphylococcus aureus, Acinetobacter baumannii, Streptococcus pneumoniae, Klebsiella oxytoca, and Bacillus spp. from the conjunctival sac only in patients infested with D. folliculorum. This indicates an increased probability of colonization by pathogenic bacteria in patients with demodicosis. Therefore, patients infested with D. folliculorum should undergo a microbiological examination of conjunctival swabs.

A New Species of Demodex (Acariformes: Prostigmata) Observed in the Mouflon, Ovis aries musimon (Artiodactyla: Bovidae) with Data on the Parasitism and Occurrence of Other Ectoparasites.

A greater understanding of mite biodiversity and ecology can explain their preference for microhabitats within host bodies, i.e., as ecto-, meso-, and endoparasites. Similarly, learning about the patterns formed by mite communities in wild animals can shed light on the mechanisms of parasitosis development in their domesticated counterparts. Hence, the present study examined the acarofauna of the mouflon, introduced to Poland in the early 20th century from a region of endemic occurrence. Forty-one individuals were examined for the presence of ectoparasites between 2010 and 2013; later, skin fragments were analysed for the presence of skin mites. A new species of Demodecidae, Demodex musimonis sp. nov., was discovered in the skin of the pasterns of 14.6% mouflons, as well as the ectoparasitic tick Ixodes ricinus (prevalence 29.3%) and ungulate-typical fly Lipoptena cervi (34.1%). However, no mites typical for ovine Ovis (Psorergatidae, Psoroptidae) were noted, nor any colonisation of microhabitats by species from local ungulates, resulting from the loss of original parasites during the introduction. A comparison of the acarofauna of the mouflon and domestic sheep Ovis aries aries suggests that a mite community with a complex structure and the co-occurrence of different families may be formed. However, it is not known whether the acarofauna of domestic sheep is derived from wild ancestors or the process of domestication. Even so, the peculiar Demodecidae must have been part of the natural parasitofauna of wild sheep, of which only D. musimonis sp. nov. has been recognised so far.

STANDARDIZED SKIN SURFACE BIOPSY - A BETTER DIAGNOSTIC OPTION FOR DEMODICOSIS IN MACULAR ROSACEA IN VIETNAMESE PATIENTS

Introduction: Demodicidosis is a chronic skin disease, caused by two species of Demodex (D. folliculorum and D. brevis). Demodex infected individuals are mainly symptomless and may have pathogenic symptom only when mite density is high within the skin.Objectives: To compare the value of the Standardized skin surface biopsy (SSSB) and direct microscopic examination with KOH (DME) for assessing Demodex density.Methods: Fifty patients with demodicosis were determined Demodex by SSSB and DME. Comparision of the similarity of test results between the two methods was conducted by Cohen’s Kappa statistic.Results: The positive test rate of SSSB is 90.0%, of DME is 82.0%. The percentage of patients who tested positive for both methods was 76.0%, and the negative for both methods was 4.0%. Demodexdensity &gt; 5/cm2of SSSB was 47.9% higher than DME of 29.2%. There was quite similarity of Demodexdensity between SSSB and DME with coefficient kappa = 0.62. Conclusion: SSSB is more sensitive method for detecting Demodex than DME, particularly in patients with macular lesions, vasodilatation, U-shaped distribution, located on the nose and nasolabial sulcus.

Identification and genetic characterisatin of cathepsin L in Demodex.

Owing to difficulties in obtaining functional gene sequences, molecular pathogenic mechanisms in Demodex have been understudied. In this study, overlap extension PCR was used to obtain the sequences of cathepsin L (CatL), a pathogenicity-related gene, to provide a foundation for subsequent functional research. Demodex folliculorum and Demodex brevis mites were obtained from the face skin of Chinese individuals, and Demodex canis mites were isolated from the skin lesions of a dog. RNA was extracted and used to synthesise double-stranded cDNA. PCR amplification, cloning, sequencing, and bioinformatics analysis of CatL were performed. CatL gene sequences of 1005, 1008, and 1008bp were successfully amplified for D. brevis, D. folliculorum, and D. canis, respectively. These sequences showed 99.9 or 100% identity with templates previously obtained by RNA-seq. The Maximum Likelihood (ML) phylogenetic tree showed that D. folliculorum clustered with D. canis first, then with D. brevis, and finally with other Acariformes mite species. The three Demodex species had nine similar motifs to those of Sarcoptes scabies, Dermatophagoides pteronyssinus, and Dermatophagoides farinae, and motifs 10-13 were valuable for identification. CatL proteins of Demodex species were predicted to be approximately 38kDa, be located in lysosomes, have a signal peptide but no transmembrane region, and have two functional domains, I29 and Pept_C1. However, interspecific differences were observed in secondary and tertiary protein structures. In conclusion, we successfully obtained CatL sequences of three Demodex species by overlap extension PCR, which creates conditions for further pathogenic mechanism studies.

Is there a relationship between keratoconus and ocular Demodex mites?

The background of this study was to evaluate the relationship between keratoconus (KC) occurrence and ocular Demodex infestation together with the effects of Demodex on the ocular surface. Thirty-eight eyes of 20 KC patients (KC group) and 40 eyes of 20 age- and sex-matched healthy subjects (control group) were included in this cross-sectional study. Demodex species (folliculorum/brevis), clinical symptoms such as eye rubbing, Ocular Surface Disease Index (OSDI), corneal topography findings, tear break-up time (TBUT), and Schirmer test scores were evaluated. KC eyes were also divided into two subgroups according to KC severity and presence of Demodex. Demodex was detected using conventional light microscopy. The mean age was 25.90 ± 7.01 years in the KC group, and 26.52 ± 8.94 years in the control group (P = 0.731). While unexpectedly no Demodex were detected in the control group, Demodex were detected in the KC group, including 8 eyes (21.1%) with Demodex folliculorum, and 10 eyes with D. folliculorum + Demodex brevis (26.3%) (P < 0.001). As the KC severity worsened, the percentage of eyes with Demodex mites increased (43.8% in the mild/moderate subgroup and 66.7% in the severe subgroup, P < 0.001). The number of rubbing eyes and OSDI scores were significantly higher, and TBUT levels were significantly lower in the KC Demodex + and Demodex - subgroups than the control group (P < 0.001 for all), but there is no significant difference between the KC Demodex + and Demodex - subgroups regarding ocular surface parameters (P = 1.0). Although the number of patients is relatively small and there is no follow-up data after Demodex treatment, KC and ocular Demodex infestation seem to be associated. Demodex-related inflammation and associated eye rubbing may contribute to KC progression.

Mange: Epidemiology and ivermectin efficacy in goats and application of zero-inflated negative binomial regression in Uba Debre Tsehay, southern Ethiopia

Mites are one of the most common and widely distributed ectoparasites of goats in Ethiopia, contributing to major burdens in livestock productivity in the country. Between February 2021 and July 2021, this study was conducted to estimate the prevalence of mange mites, assess the potential risk factors, identify the species infesting goats, and evaluate the efficacy of ivermectin in naturally infested goats in the Uba Debere Tsehay district of Gofa Zone, Southern Ethiopia. A cross-sectional study, longitudinal field efficacy, and questionnaire survey were conducted. A total of 384 goats suspected of having mange were scraped for mite prevalence and count. The mite count data were analyzed using zero-inflated negative binomial (ZINB) models with explanatory variables. The ZINB models indicated that a substantial proportion of the observed zero mite count reflected a failure to detect mites in suspected goats, meaning that the estimated true prevalence was much higher than the apparent prevalence as calculated using a simple proportion of nonzero mite counts. Overall prevalence of mange was 21.87% (84/384) in the study areas. Sarcoptes species (21.09%) and Demodex species (0.78%) were the mite genera identified in this study. Among goats with poor, medium, and good body conditions, mite prevalence was 36.3%, 12.3%, and 10.9%, respectively. Both the prevalence and intensity of infestation were significantly associated with body condition scores, but other risk factors were not. The questionnaire survey indicated that 85.94% of the participants preferred to use modern treatment options (ivermectin 1%, injection) and 76.56% (98/128) respondents replied that ivermectin treatment is effective. Wilcoxon rank-sum test analysis shows that there was significantly (P<0.05) fewer mites counted on goats treated with ivermectin than on untreated goats at each count up to day 56 after treatment. No live mites were found on any treated animal on days 28 and 56. Mixed ANOVA indicated that there was a significant difference within treatment groups. This study showed that mites are one of the constraints to goat production in the study area and ivermectin was highly effective against Demodex and Sarcoptes mites in goats. Hence, there is a need to create awareness about the impact of mange on goat production, and appropriate ivermectin treatment against mites should be implemented.

Demodex murilegi and Demodex obliquus, two new specific skin mites from domestic cat Felis catus, with notes on parasitism.

The Demodecidae are skin and tissue parasites of mammals with high host, topical, and topographic specificity. They may cause a demodecosis, typically observed in pets and humans. Numerous mammal species have been found to have several, specific demodecids, which inhabit different microhabitats. Thus far, two species have been known from the domestic cat, namely Demodex cati Megnin, 1877 (Acariformes: Demodecidae) and D. gatoi Desch and Stewart, 1999; however, there have been indications for the presence of other demodecid mites in this host. Presently, two other species are described, D. murilegi sp. nov. associated primarily with the skin from the area of lips and nose, and D. obliquus sp. nov. associated with the skin of the lower part of the limb. They exhibit morphological discreteness in terms of qualitative traits significant for Demodecidae taxonomy. Demodex murilegi sp. nov. is larger than both known species, and D. obliquus sp. nov. is intermediate in length between them. It is likely that infection with different Demodex species may result in variable symptoms and courses of demodecosis; however, a correct identification of the species causing the parasitosis is needed to confirm this. Thus, the present study compares the taxonomic traits of four cat demodecid mites.