Molecular and Morphological Identification of Dermanyssoid Mites (Parasitiformes: Mesostigmata: Dermanyssoidea) Causatives of a Parasitic Outbreak on Captive Snakes.

A parasitic outbreak caused by dermanyssoid mites in a herpetarium of the Metropolitan area of the Valley of Mexico is revealed. This outbreak was caused by Hemilaelaps triangulus (Ewing), but a second mite species, Ophionyssus natricis (Gervais), was found in low abundance. The parasitic load is analyzed, and the morphological and molecular diagnostic characters to identify each of the two species involved are given. A barcode analysis is presented, and two more molecular markers are presented and analyzed. Hemilaelaps triangulus is recorded for the first time in Mexico, and this is the first record of massive infestation on captive snakes caused by ixodorhynchid mites, and DNA sequences of ixodorhynchid mites are publicly available for the first time.

Histopathological Analysis of 226 Patients With Rosacea According to Rosacea Subtype and Severity.

BACKGROUND: The histopathological features of rosacea have not been described in detail. OBJECTIVE: To evaluate the histopathological features of rosacea according to clinical characteristics such as subtype and severity. METHODS: We retrospectively analyzed histopathological findings in 226 patients with rosacea, which included 52 patients with the erythematotelangiectatic rosacea (ETR) and 174 patients with the papulopustular rosacea (PPR) subtype. The frequency of each histopathological finding was compared between subtypes. Histopathological features were also compared according to the severity, through subgroup analysis within each subtype group. RESULTS: Perivascular and perifollicular lymphohistiocytic infiltration were common dermal findings in both subtype groups, but the intensity of dermal inflammatory infiltration was higher in PPR than in ETR. Follicular spongiosis and exocytosis of inflammatory cells into hair follicles were noted in both subtypes; but these findings were significantly more common in the PPR subtype. Vascular changes (telangiectasia and proliferation) and solar elastosis were common histopathological findings in both subtypes, with no difference in frequency between subtype groups. Demodex mites were identified in about 40% of patients, and the frequency of demodex mites did not differ between subtype groups. The intensity of perifollicular inflammation and the presence of follicular inflammatory reactions were dependent on the severity of rosacea in both subtype groups. CONCLUSIONS: The intensity of inflammatory reactions, especially perifollicular infiltration, was higher in PPR patients than in ETR patients. Rosacea has a spectrum of histopathological features that are related to clinical progression between rosacea subtypes.

Human demodicosis: revisit and a proposed classification.

Human Demodex mites (Demodex folliculorum and Demodex brevis) hold a high rank in the evolutionary and phylogenetic hierarchy of the skin microbiome, although in most people their presence is of no consequence. While human demodicosis is a skin disease sui generis, it can mimic many other inflammatory dermatoses, such as folliculitis, rosacea and perioral dermatitis, leading to unspecific and confusing descriptions in the literature. Here, we propose to classify human demodicosis into a primary form and a secondary form, which is associated mainly with immunosuppression. The clinical manifestations of primary demodicosis may include (i) spinulate demodicosis, currently known as pityriasis folliculorum, involving sebaceous hair follicles without visible inflammation; (ii) papulopustular/nodulocystic or conglobate demodicosis with pronounced inflammation affecting most commonly the perioral and periorbital areas of the face; (iii) ocular demodicosis, inducing chronic blepharitis, chalazia or, less commonly, keratoconjunctivitis; and (iv) auricular demodicosis causing external otitis or myringitis. Secondary demodicosis is usually associated with systemic or local immunosuppression. Treatment is only weakly evidence based, and the most effective concentrations of acaricides remain to be determined. Optimization of an in vitro or ex vivo culture model is necessary for future studies. Endosymbiosis between certain bacteria and Demodex mites in the pathogenesis of demodicosis deserves more attention. Further clinical observations and experiments are needed to prove our hypothesis.

Ácaros plumícolas (Acari: Astigmata) em aves do Cerrado do Distrito Federal, Brasil / Feather mites (Acari: Astigmata) on birds of Cerrado in Distrito Federal, Brazil

O objetivo do estudo foi identificar os ácaros plumícolas em aves do cerrado. O mesmo foi realizado na Fazenda Água Limpa (FAL), Distrito Federal, Brasil, entre janeiro e agosto de 2002. As aves foram capturadas com rede de neblina e anilhadas. Foram amostradas 696 aves pertencentes a 83 espécies e 25 famílias de Passeriformes e não-Passeriformes. Foram encontrados ácaros plumícolas pertencentes a cinco famílias: Analgidae, Trouessartiidae, Proctophyllodidae, Avenzoariidae e Psoroptoididae. O presente trabalho contribui com novos registros de ácaros plumícolas nos hospedeiros capturados. A família Proctophyllodidae e o gênero Pterodectes foram os mais prevalentes grupos de ácaros plumícolas coletados. Considerando todas as aves capturadas, a prevalência foi de 44,98 por cento. As maiores prevalências (>50 por cento) de ácaros plumícolas foram encontradas para as famílias Trochilidae, Conopophagidae, Furnariidae, Tityridae, Turdidae, Mimidae, Cardinalidae e Parulidae.

The goal of this study was to identify feather mites on Cerrado birds. This study was conducted at Fazenda Água Limpa (FAL), Distrito Federal, Brazil, between January and August 2002. Birds were captured with mist nets and banded. Were sampled 696 birds, belonging to 83 species and 25 bird families of Passeriformes and non-Passeriformes. Feather mites were found on five families: Analgidae, Trouessartiidae, Proctophyllodidae, Avenzoariidae and Psoroptoididae. The present work reports new occurrences of feather mites on captured hosts. The family Proctophyllodidae and the genus Pterodectes were the most prevalent group of feather mites collected. Tyrannidae, Pipridae, Emberizidae and Thraupidae were the bird families with most host numbers, with parasites from three taxa: Trouessartiidae, Proctophyllodidae and Analgidae. Considering the birds captured the prevalence was 44.98 percent. Trochilidae, Conopophagidae, Furnariidae, Tityridae, Turdidae, Mimidae, Cardinalidae, and Parulidae were the families with major feather mites prevalence (>50 percent).

Comparison of Demodex folliculorum density in haemodialysis patients with a control group.

BACKGROUND: Demodex folliculorum (DF) is resident in human pilosebaceous follicles. Mite density is low in healthy skin. Many cases of demodicosis in association with immunosuppression have been reported. Patients undergoing haemodialysis are also immunosuppressed. OBJECTIVE: We aimed to compare the Demodex folliculorum density in haemodialysis patients and healthy subjects. METHODS: Mite density of 87 patients undergoing haemodialysis was compared with that of age- and sex-matched controls. Two samples of standardized skin surface biopsies were taken from each subject from the forehead, cheek and nose. The number of mites counted on the surface area of 1 cm2 was accepted as the density of DF. The length and width of mites were measured by oculometer. RESULTS: DF density was found in 17 (19.54%) of the 87 dialysis patients and in 9 (10.34%) of 87 controls. A mean mite density of 5.11+/-5.65 was found in dialysis patients and of 2.55+/-1.6 in controls. Differences between the two groups in mite density were not statistically significant (P=0.13). There was also no significant difference in mite length between the two groups (P=0.06). There was, however, a significant difference in mite width (P=0.018). CONCLUSION: Despite the presence of sebaceous gland atrophy in haemodialysis patients, the higher density of DF in these patients than controls supports the supposition that this mite can increase immunosuppression.

Ácaros predadores (Acari) associados à cultura do morango (Fragaria sp., Rosaceae) e plantas próximas no Estado do Rio Grande do Sul / Predatory mites (Acari) associated with strawberry and neighboring plants in the State of Rio Grande do Sul

O objetivo deste estudo foi determinar as espécies de ácaros predadores associados à cultura do morango e em plantas associadas, no estado do Rio Grande do Sul. Este estudo foi conduzido nos municípios de Bom Princípio, Capitão e Lajeado em plantações de morango da variedade Oso Grande em túnel baixo. As avaliações foram feitas mensalmente entre agosto de 2002 e março de 2004. Nas plantas de morango, as amostras foram constituídas de três folhas coletadas em cada uma das 15 plantas escolhidas ao acaso, totalizando 45 folhas/campo. Nas plantas associadas, o esforço de amostragem foi de uma hora para cada planta avaliada. Ácaros das famílias Ascidae, Parasitidae, Phytoseiidae, Cunaxidae, Erythraeidae, Stigmaeidae e Tydeidae foram observados associados com o ácaro rajado, Tetranychus urticae Koch, 1836, praga importante na região onde este estudo foi conduzido. Vinte espécies foram identificadas, 14 das quais pertencem à família Phytoseiidae. Phytoseiulus macropilis (Banks, 1905) e Neoseiulus californicus (McGregor, 1954) foram as espécies mais comuns. Nas plantas asssociadas, a maior diversidade foi observada em Richardia sp. (seis espécies), Agerantum conyzoides L.(quatro espécies) e Sonchus oleraceus L., Bidens pilosa L.e Rumex sp. (três espécies). Uma chave docotômica é apresentada para a identificação das espécies.

The aim of this study was to determine the species predatory mites on strawberry crop and associated plants in the State of Rio Grande do Sul. It was conducted in Bom Princípio, Capitão and Lajeado counties, in crops of strawberry Oso Grande variety in low tunnels. The evaluations were done monthly between August 2002 and March 2004. In the plants of strawberry, the samples were constituted of three leaves collected in each of 15 plants taken randomly, totaling 45 leaves/field. In the associated plants, the sampling effort was of one hour for each plant evaluated. Mites of the families Ascidae, Parasitidae, Phytoseiidae, Cunaxidae, Erythraeidae, Stigmaeidae and Tydeidae were observed associated with the two-spotted spider mite, Tetranychus urticae Koch, 1836, important pest of this crop in the region where the study was conducted. Twenty species were identified, 14 of which belong to the family Phytoseiidae. Phytoseiulus macropilis (Banks, 1905) and Neoseiulus californicus (McGregor, 1954) were the most common species. On associated plants, the highest diversity of predatory mites was found on Richardia sp. (six mite species), Agerantum conyzoides L. (four mite species) and Sonchus oleraceus L., Bidens pilosa L. and Rumex sp. (three mite species). A dichotomous key is presented for the separation of the species collected.

A clinico-pathological approach to the classification of human demodicosis.

BACKGROUND: Demodicosis is a parasitic skin disease caused by the follicle mites Demodex folliculorum and Demodex brevis. Although there are several clinical variants of this disease, a clear classification is missing. OBJECTIVE: To characterize the clinical features and course of the different forms of demodicosis. PATIENTS: Prospective study of 87 patients with clinical symptoms of demodicosis and positive acarological findings. Each patient was examined an average of six times during the treatment period. RESULTS: We suggest that demodicosis be divided into both primary and secondary types. The usual etiological agent of primary demodicosis is D. folliculorum, which causes an erythemato-squamous eruption in the facial T-zone. The rash starts on unaltered skin and covers 8 - 15 % of the face. Pruritus accompanies the onset of the rash, while erythema is first apparent after papulo-pustules are seen and disappears after treatment. Half the patients show seasonal exacerbations. Secondary demodicosis is usually caused by D. brevis and characterized by a symmetrical malar papulo-pustular eruption. It develops on diseased skin and covers 30 - 40 % of the face. Pruritus starts after the lesion exacerbation, but erythema precedes the papulo-pustular phase and persists after treatment. Most patients flare during the summer. The facial distribution, seasonality and pathogenesis, as well as the species of mite involved, must be taken into consideration in separating the various forms of demodicosis.

Serial determinations of Der p 1 and Der f 1 show predominance of one Dermatophagoides species.

One dust sample each month was collected for an average of 11 months throughout the year from the bedroom carpet of 39 mite allergic, asthmatic individuals living in the Tampa Bay area of Florida. Dust samples were collected from a square meter area from the bedroom carpet for 2 min using a portable vacuum cleaner and analyzed using two-site monoclonal antibody assays. The geometric mean of Dermatophagoides allergens Der p 1 and Der f 1 levels measured in each individual home was used in the statistical analysis of the results and reflects the average allergen level per year per home. Der p 1 levels were greater than Der f 1 in 21 homes; five homes had between 1.1 and 5 times more; one home had between 5 and 10; and 15 had between 10 and 175. Der f 1 levels were greater than Der p 1 in 18 homes; seven homes had between 1.1 and 5 times more; four had between 5 and 10; and seven homes had between 10 and 44. Spearman rank analysis of the results yielded a negative correlation coefficient (Rho) = -0.213 (p = 0.19) between Der p 1 and Der f 1 levels. These data suggest that when mite allergen levels reach a geometric mean value of approximately 2 micrograms/gram of dust throughout a year, one mite species predominates over the other.

Uso de invermectina en sarna noruega / Use of ivermectin in norwegian scabies

La Sarna Noruega es más difícil de tratar que la escabiosis común, pudiendo requerir repetidos tratamientos con escabicidas y a veces el uso de varios agentes de manera secuencial en ocasiones con fracaso. Ivermectina es un agente antiparasitario usado en la práctica veterinaria contra un amplio rango de nemátodos, insectos y parásitos acarinos. En humanos, ha sido ampliamente usado en Oncocercosis. Reportes anecdóticos de su uso con curación en pacientes con infestación por Sarcoptes scabie sugieren que esta enfermedad ectoparasitaria puede ser tratada con Ivermectina. La dosis oral recomendada es de 200 ug/kg para escabiosis no complicada, una segunda dosis para los aun sintomáticos es recomendada. Se reporta un paciente con SIDA y Sarna Noruega tratado exitosamente con Invermectina oral

Pneumonyssoides caninum, the canine nasal mite, reported for the first time in a fox (Vulpes vulpes).

This is the first report describing the finding of the canine nasal mite, Pneumonyssoides caninum, in a silver fox (Vulpes vulpes). It is also the first time P. caninum has been found in a species other than the dog (Canis familiaris). A severely debilitated 10-month-old, male silver fox was euthanised due to suspected renal failure. During autopsy, a female mite matching the description of P. caninum was found in the nasal cavity of the fox. The finding of P. caninum in the fox suggests the existence of a new host, or at the very least a transient host. The fox's role in maintaining and/or propagating canine nasal mite infection needs to be explored.

Sarna noruega

Presentamos un caso de sarna noruega en una enferma con artritis reumatóide y sometida a corticoterapia general. Comentamos las principales características clínicas, etio-patogénicas, histopatológicas y terapéuticas de esta rara entidad.