Factors Affecting the Prevalence of House Dust Mite in Tekirdag and Istanbul Provinces in Comparison with House Dust Mite Population of Sivas Province During the Same Period

Objective: This study aimed to examine the frequency of house dust mite according to various variables and determine the house dust mite population in these provinces in house dust samples collected in the same period from Istanbul and Tekirdag provinces, which is located on the coastal part of the Marmara Region, and Sivas province, which has different climatic and geographic characteristics from these provinces. A comparison was done from each province. Methods: Between May and August 2018, a total of 100 powder samples were prepared by a lactic acid precipitation method that was examined microscopically. Besides, some variables in Tekirdag and Istanbul provinces were applied to participants by face-to-face interview method from a questionnaire. Results: House dust mite was found with a rate of 66.7% in Istanbul and 61.5% in Tekirdag; however, house dust mite was not found in Sivas province. According to survey results, the frequency of house dust mite detection is 1-4. It increased according to the fact that it is located between floors, cleaning was every 15 days, no smoking at home and insufficient sun exposure. No statistically significant difference was found according to the presence of plants and/or animals in the house and way of heating. Conclusion: Measures to be taken against house a dust mite, which is the most essential component of house dust with allergic content, are observed to be important in reducing complaints of sensitive people by especially considering the climate, geographic characteristics and general hygienic conditions. According to investigations, Baloghella melis, one of the mites detected in dust samples taken from Istanbul, has been determined to be a new record in Turkey. This study will contribute to Turkey with this aspect fauna of house dust mites.

The Role of Dust Mites in Allergy.

House dust mites are an unsurpassed cause of atopic sensitization and allergic illness throughout the world. The major allergenic dust mites Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis are eight-legged members of the Arachnid class. Their approximately 3-month lifespan comprises egg, larval, protonymph, tritonymph, and adult stages, with adults, about one fourth to one third of a millimeter in size, being at the threshold of visibility. The geographic and seasonal distributions of dust mites are determined by their need for adequate humidity, while their distribution within substrates is further determined by their avoidance of light. By contacting the epithelium of the eyes, nose, lower airways, skin, and gut, the allergen-containing particles of dust mites can induce sensitization and atopic symptoms in those organs. Various mite allergens, contained primarily in mite fecal particles but also in shed mite exoskeletons and decaying mite body fragments, have properties that include proteolytic activity, homology with the lipopolysaccharide-binding component of Toll-like receptor 4, homology with other invertebrate tropomyosins, and chitin-cleaving and chitin-binding activity. Mite proteases have direct epithelial effects including the breaching of tight junctions and the stimulation of protease-activated receptors, the latter inducing pruritus, epithelial dysfunction, and cytokine release. Other components, including chitin, unmethylated mite and bacterial DNA, and endotoxin, activate pattern recognition receptors of the innate immune system and act as adjuvants promoting sensitization to mite and other allergens. Clinical conditions resulting from mite sensitization and exposure include rhinitis, sinusitis, conjunctivitis, asthma, and atopic dermatitis. Systemic allergy symptoms can also occur from the ingestion of cross-reacting invertebrates, such as shrimp or snail, or from the accidental ingestion of mite-contaminated foods. Beyond their direct importance as a major allergen source, an understanding of dust mites leads to insights into the nature of atopy and of allergic sensitization in general.

Species Identification and Prevalence of House Dust Mites as Respiratory Allergen in Kindergartens of the Bandar Abbas City.

The aim of this study was to identify the species and prevalence of house dust mites (HDMs) in kindergartens in Bandar Abbas, south of Iran. In this study 10 kindergartens were selected randomly in five areas of Bandar Abbas. Two dust samples were collected from each sampling place with a vacuum cleaner. Mites were isolated and mounted in Hoyer's medium and identified using a morphology-based key. In total, 1758 mites were collected and identified, whichconsisted of five species: Dermatophagoides pteronyssinus (31.06%), D. evansi (23.49%), D. farinae (17.75%), Ornithonyssus bacoti (19.45%), and Cheyletus malaccensis (8.25%). Two main allergenic dust mite species D. pteronyssinus and D. farinae, coinhabited and were collected from all of kindergartens. Results of this study have revealed that D. pteronyssinus is the most prevalent HDMs in Bandar Abbas Kindergartens and all studied areas are contaminated by more than one dust mite Regarding the high prevalence of HDMs in Bandar Abbas kindergartens, implementation of strict control measures is necessary for reduction of mite population and prevention of children respiratory diseases and other allergic disorders in this city.

[Blomia tropicalis: A house dust mite in the tropics]. / Blomia tropicalis : un acarien sous les tropiques.

INTRODUCTION: Blomia tropicalis is a mite that belongs to the superfamily of Glycyphagidae. Initially described as a storage mite, it is now considered as a house dust mite of tropical and sub-tropical areas. STATE OF THE ART: Sensitization to this mite is very common in South America and Southeast Asia. Epidemiological studies have also found sensitization to this mite in Africa and Central America. Blo t 5 is the major allergen of B. tropicalis. Co-sensitization to other house dust mites such as Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) is very common. Cross-reactivity has been described but recombinant allergens revealed by molecular biology techniques do not explain this cross-reactivity. Sensitization to B. tropicalis seems to begin at the age of 36 months, the incidence increases until adulthood, and decreases from the age of 50. The involvement of B. tropicalis in allergic rhinitis and asthma is well described. It is also implicated in other allergic diseases. Few studies have assessed the therapeutic strategies available against this mite but immunotherapy is widely used. PERSPECTIVES: Studies are needed to better understand the role of B. tropicalis in human diseases and to develop specific treatments.

Mite allergen extracts and clinical practice.

OBJECTIVE: To provide physicians, researchers, and other interested health care professionals with information about how mite source materials and allergen extracts are manufactured, including the critical process parameters that can affect the final composition of allergenic extracts available for clinical use. DATA SOURCES: A PubMed search was performed using focused keywords combined with relevant regulatory documents and industry guidelines. STUDY SELECTIONS: The information obtained through literature and specialized books was evaluated and combined with the personal expertise and experience of the authors. RESULTS: Dermatophagoides farinae and Dermatophagoides pteronyssinus are the primary species responsible for allergen sensitizations and allergy symptoms in genetically predisposed individuals. Storage mites belonging to the families Glycyphagidae, Echimyopodidae, and Acaridae can also be relevant sources of indoor mite allergens. The cultivation and purification processes used to produce mite raw materials play a critical role in the final composition of mite allergen extracts. Mite extract standardization in the United States is based on total allergenic activity with respect to a single national standard, whereas in Europe consistency is ensured by in-house standards and international references. Because of the limitation of allergen avoidance and pharmacotherapy for patients with severe allergic rhinitis and asthma, house dust mite subcutaneous immunotherapy or sublingual immunotherapy can be an invaluable treatment option for them. CONCLUSION: Differences in manufacturing processes and extract standardization approaches may lead to differences in extract quality and potency. Physicians should be aware of these potential sources of mite extract variability. Use of well-standardized house dust mite extracts would be critical for success in the diagnosis and treatment of house dust mite allergy.

Early House Dust Mite Sensitivity in Mumbai Children.

OBJECTIVE: To identify house dust mite (HDM) sensitivity by skin prick test in children with allergic rhinitis, allergic wheezing and eczema. METHODS: In this prospective study, children with persistent or recurrent allergic symptoms of rhinitis, wheezing and eczema were enrolled to undergo skin prick testing. Sensitivity was checked for three mites: Dermatophagoide farinae, Dermatophagoide pteronyssinus, and Blomia tropicalis. RESULTS: Total 92 children underwent skin prick test; 49 (53.2 %) showed significant positivity to one or more dust mite. In the HDM sensitized group, a positive family history of allergic disorders was present in 32 children (65.3 %). In the HDM sensitized group, 18 (36.7 %) children had allergic rhinitis. The youngest child in this group was 12-mo-old. Ten (55.55 %) children were less than 24 mo of age. Significant sensitization to mites was detected in 7 (14.28 %) children with eczema. All children were below 24 mo of age. In children with a tendency to wheeze frequently without any evidence of infections or other systemic disease, 24 (48.9 %) had sensitization to HDM. The youngest child was 15 mo of age. Ten (41.6 %) children were below 24 mo of age. Sensitivity to Blomia tropicalis was detected in 6 (12.24 %) children. Significantly more number of children were sensitive to D. pteronyssinus as compared to D. farinae (65.31 % vs. 46.94 %; p = 0.034). CONCLUSIONS: Children in Mumbai show early sensitization to HDM. D. pteronyssinus is the commonest offending allergen in the index study.

Studies on the Occurrence, Identification and Control of House Dust Mites at Rural Houses of Shebin El-Kom Locality, Egypt.

The present study was conducted at Elkom Elakhdar village, Shebin El-Kom, Menoufia Governorate along 2012 year seasons, to calculate and identify the species composition and the occurrence frequency of the extracted dust mites collected from three building ages at rural houses, as well as to determine the toxicity limits of different concentrations of three plant essential oils against two species of the family Pyroglyphidae the main causal of allergy to humans. The obtained results revealed that there were eleven mite species belong to five families (Pyroglyphidae, Chortoglyphidae, Glycyphagidae, Acaridae and Cheyletidae). Of the total collected mites (5276) the highest dominant percentage species was the dust mites: Dermatophagoides farinae (66.1%), followed by D. pteronyssinus (23.3%), while the percentages of the rest species: Chortoglyphus arcuatus, Lepidoglyphus destructor, Glycyphagus domesticus, Gohieria fusca, Tyrophagusputrescentiae, Caloglyphus sp, Cheyletus malaccensis, Blomia sp. and Acarus siro were ranged between 0.16-2.0%. Regarding to the effect of temperature degrees on mite population, high degrees more than 25 degrees C at summer season, decreased the numbers of D. farinae and D. pteronyssinus. Toxicological tests of the three plant essential oils against adult stages of D. farinae and D. pteronyssinus showed that lemon grass oil gave the highest toxicity effect, in comparison with geranium and thyme oils, where mortality percentages were approximately around 100% at 800 ppm concentration on both species. The LC50 of lemon grass were 228.992 and 293.615 ppm against the two species, respectively. From the results of the research, it could be recommend that it is preferable to apply control operation during summer season where the mite population density is the least, moreover, the botanical oil extracts effectively controlled the parasitic dust mites, D. farinae and D. pteronyssinus and can be used in the biological control programs, as well as, it can play effective role in the integrated management programs.

Tachornithoglyphus gen. nov.--a new genus of nidicolous Pyroglyphidae (Acariformes: Astigmata).

Tachornithoglyphus gen. nov. (Acariformes: Pyroglyphidae) is established for Tachornithoglyphus tachornis (Cruz, Cuervo and Dusbabek, 1984), comb. nov. (transferred from Guatemalichus), collected from nests of the Antillean palm swift, Tachornis phoenicobia (Apodiformes: Apodidae) in Cuba. The new genus differs from the other four genera of the subfamily Guatemalichinae, Guatemalichus Fain and Wharton, 1970, Pottocola Fain, 1971, Fainoglyphus Atyeo and Gaud, 1977, and Capitonocoptes Fain and Gaud, 1984, mainly by having the length of solenidion σ1 of genu I less than one-third that of the segment (vs. solenidion σ1I at least half as long as genu I), by the absence of famulus ε on tarsus I (vs. present), and by coxal apodemes Ia separated from each other and contiguous to the lateral parts of the epigynal arch (vs. posterior tips of apodemes Ia fused to each other and with the median part of the epigynal arch, or separated and contiguous to or fused with the median part of the epigynal arch). A detailed redescription of adults and tritonymphs of T. tachornis is provided.

Diversity of House Dust Mite Species in Xishuangbanna Dai, a Tropical Rainforest Region in Southwest China.

PURPOSE: To survey the species diversity of home dust mites (HDM) in Xishuangbanna, a tropical rainforest region in Southwest China. METHODS: From August 2010 to January 2011, mite-allergic patients and healthy controls were invited to participate. Dust samples from the patients' homes were collected, and mites in the samples were isolated. Permanent slides were prepared for morphologically based species determination. RESULTS: In total, 6316 mite specimens of morphologically identifiable species were found in 233 dust samples taken from 41 homes. The result shows that the mite family of Pyroglyphidae occupied the highest percentage of the total amount of mites collected, followed by Cheyletidae family. The most common adult Pyroglyphidae mites were Dermatophagoides (D.) farinae, D. pteronyssinus, and D. siboney. The most common mites found from other families were Blomia tropicalis, Tyrophagus putrescentiae, and Aleuroglyphus ovatus. Four main allergenic dust mite species D. farinae, D. pteronyssinus, D. siboney, and Blomia tropicalis were found to be coinhabiting in 6/41 homes. CONCLUSION: The HDM population in homes in Xishuangbanna, a tropical rainforest region in Southwest China, has its own characteristics. It has rich dust mite species and the dust mite densities do not show significant variation across seasons.

House Dust Mites in Erzincan Province.

OBJECTIVE: We aimed to determine the species of the house dust mites seen in Erzincan, the number of mites per gram of dust in the houses, and the relationship between temperature and the number of mite specimens. METHODS: For this purpose, 54 dust samples collected from 18 houses located in different districts of Erzincan province between November 2013 and January 2014. These samples were examined by a lactic acid precipitation method. RESULTS: Of the houses in which the dust samples were collected, 94.44% were found to be positive in terms of mites. A total of 844 mite specimens were isolated from the dust samples, and the mean number of mites per gram of dust was found to be 18.34. The most common species was found to be Acarus siro (55.55%) and was followed by Dermatophagoides pteronyssinus (50.00%), Tyrophagus putrescentiae (22.22%), Histiostoma sp. (22.22%), Lepidoglyphus destructor (16.66%), T. perniciosus(11.11%), Euroglyphus maynei (11.11%), Glycyphagus privatus (11.11%), Cheyletus sp. (11.11%), Tarsonemus sp. (11.11%), and Tetranychus sp. (11.11%). CONCLUSION: Mite-holding rate of the houses in Erzincan province was found to be 94.44%. The mean number of mites per gram of dust was found to be 18.34. The most common mite species was A. siro, which was followed by D. pteronyssinus.

Are skin prick tests really safe? A case of anaphylaxis caused by skin prick testing with inhalant allergens

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Domestic mites on the hair/scalp, pillows, and mattresses of mite-sensitized children in a subtropical area

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House dust mite allegry immunotherapy tablet

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Revision of the subfamily Onychalginae Fain, 1988 (Acariformes: Pyroglyphidae)-ectoparasites of passerine birds.

The subfamily Onychalginae Fain, 1988 (Acariformes: Pyroglyphidae) is a monophyletic lineage comprising the closest parasitic relatives of the free-living pyroglyphid house dust mites. Onychalgine mites parasitize passerine birds of the families Estrildidae, Passeridae, and Ploceidae in Africa and South America (a single record of Onychalges spinitarsis from a piciform bird requires confirmation). We revise this subfamily based on external morphology of adults and immature stages using light and scanning electron microscopy and give a key to species. Onychalginae includes 2 genera: Onychalges Gaud and Mouchet, 1959 (6 species) and Paramealia Gaud, 1968 (1 species). The genus Kivuicola Fain, 1971 syn. nov. is synonymized with Onychalges, and its single species K. kivuana Fain, 1971 syn. nov. is considered as a putative synonym of O. odonturus Gaud, 1968. Onychalges spinitarsis (Fain and Gaud, 1984) is considered as a species inquirenda.

Species diversity of house dust mites in Beijing, China.

Even though house dust mites are one of the most important allergens, there have been few studies in China for their identification and diversity. In this study, we reported that Dermatophagoides siboney was found for the first time in Beijing, China, in a temperate zone and it was also the first reported in Asia. This survey of mite prevalence was carried out in several districts of Beijing, a city of thirty million people. House dust samples were collected from 38 homes of mite-allergic patients who visited our Allergy Department from December 2008 to January 2010. Out of 345 house dust samples collected, 64% contained mites. Dermatophagoides farinae was the predominant species in the mite population found and Dermatophagoides pteronyssinus was second, and Dermatophagoides siboney was the third. The positive rates of samples were higher in single-story homes and lower buildings. The seasonal density distribution of house dust mites showed the highest mite concentration in September through October, followed by May through July, December to next January; and lowest in March and November.

Mimotope identification using phage displayed random peptide libraries against monoclonal antibodies specific to house dust mite.

Random heptapeptide T7 and random 12mer M13 phage libraries were employed to identify mimotopes binding to monoclonal antibodies (MAb) specific to house dust mite. After selection of bound phage by bio-panning and determination of binding specificity, DNA of selected bound phages was amplified, sequenced and aligned for peptide similarity. Eight mimotopes which were partially matched with Der f 15 allergen were predominant. The amino acid regions, 411-429 and 480-503 of Der f 15 allergen, appeared to be the main epitope clusters. Five mimotopes of MAb B2 and one mimotope of MAb B1 matched with Der p 1 and Der f 2 precursor, respectively.

Seasonal dynamics of house dust mites in dust samples collected from sleeping places in north-western Poland.

The most common families of mites found in house dust are Pyroglyphidae, Glycyphagidae and Acaridae; all are a source of many antigens responsible for allergic diseases. The aim of this study was to examine the seasonal dynamics of allergenic mite populations in dust samples collected from sleeping places in apartments in north-western Poland. The mites were isolated from the dust using a saturated saline floating method. In 132 dust samples we determined: Dermatophagoides farinae, Dermatophagoides pteronyssinus, Euroglyphus maynei, Hirstia sp., Chortoglyphus arcuatus, Lepidoglyphus destructor, Gohieria fusca and Cheyletus sp. The greatest frequency was observed for D. farinae, D. pteronyssinus, Ch. arcuatus and Cheyletus sp., in the fourth quarter and D. farinae in the third quarter. Smaller coefficients of dominance were found for D. pteronyssinus, Ch. arcuatus and Cheyletus sp., and their greatest mean concentrations were found in the first and fourth quarters. Given the division of the year into heating and non-heating seasons, mites D. farinae and D. pteronyssinus achieved the highest mean concentration in the first season, and Cheyletus sp. in the second season. The analysis of the participation of developmental stages showed that the adults of D. farinae were more prevalent than juveniles in the first, second and third quarters, and imago stages of D. pteronyssinus were more numerous in relation to juveniles in the first, third and fourth quarters. The results confirm the high incidence of house dust mites in sleeping places in north-western Poland dwellings; the best conditions for the development of these mites, mainly D. farinae and D. pteronyssinus, occur in the fourth quarter and are the least favourable in the second quarter. In many cases, these results are consistent with data from other parts of Poland collected by various authors.

Molecular identification of house dust mites and storage mites.

Mites are known causes of allergic diseases. Currently, identification of mites based on morphology is difficult if only one mite is isolated from a (dust) sample, or when only one gender is found, or when the specimen is not intact especially with the loss of the legs. The purpose of this study was to use polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the ITS2 gene, to complement the morphological data for the identification of mites to the species level. For this, six species were cultured: Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Tyrophagus putrescentiae, Aleuroglyphus ovatus and Glycycometus malaysiensis. Genomic DNA of the mites was extracted, quantified, amplified and digested individually with restriction enzymes. Hinf I and Ple I differentiated the restriction patterns of D. pteronyssinus and D. farinae. Bfa I and Alu I enzymes differentiated B. tropicalis and G. malaysiensis. Ple I enzyme was useful for the differentiation between T. putrescentiae and A. ovatus. Bfa I was useful for the differentiation of G. malaysiensis from the rest of the species. In conclusion, different species of mites can be differentiated using PCR-RFLP of ITS2 region. With the established PCR-RFLP method in this study, identification of these mites to the species level is possible even if complete and intact adult specimens of both sexes are not available. As no study to date has reported PCR-RFLP method for the identification of domestic mites, the established method should be validated for the identification of other species of mites that were not included in this study.

The fauna and distribution of house dust mites in residential homes of Bandar Abbas District, Southern Iran.

This study was designed to determine the occurrence, distribution and abundance of house dust mites (HDM) in residential homes in Bandar Abbas (Hormozgan Province), because of numerous complaints of allergies in this oriental city. The study area was divided in five sampling zones based on population density and geographical distribution. In each sampling zone 10 houses were randomly selected. A total of 50 home dust samples were collected using a portable vacuum cleaner for 2 min from 1 m(2) of the surface of mattresses, carpets, sofas and furniture in residential houses. After collection, samples were immediately frozen. Mite species were identified and counted using standard methods and keys. Of the sampled houses 88% (44 houses) were contaminated with at least one HDM species. Three species were identified: Dermatophagoides pteronyssinus (63.1%), D. farinae (32.8%) and D. evansi (4.1%) (Pyroglyphidae). Our findings indicate a relationship between HDM density and moisture and temperature of residential places. The high contamination rate of residential houses (88%) and the favourable environmental conditions for these arthropods stress that they should be considered as important allergic causing agents.

[House dust mites and their allergens]. / Les acariens domestiques et leurs allergènes. Biologie et écologie des acariens.

The taxonomy, anatomy, life cycle and ecology of Pyroglyphidae mites and storage mites (Acaridae, Glycyphagidae, B. tropicalis) are described. Pyroglyphidae and storage mites have similar morphologies: they are octopods, with characteristic gnathosoma and sensory hairs. Salivary glands and the mid gut produce most of the allergens excreted, which are enzymatic proteins. Biological cycles and development are similar, although fecundity is superior in storage mites compared to the Pyroglyphides. Relative humidity is the main parameter, which regulates mite development, with a higher degree of temperature and humidity required for storage mites. Bedding is the ecological niche of Pyroglyphidae, which feed on human skin. Moulds and food products are the storage mite biotope from which they spread in the dwelling. Initially considered as rural mites, storage mites are also present in urban dwellings. B. tropicalis, in tropical regions is a true domestic mite. Because of this, it is justified to denominate Pyroglyphidae "house dust mites" and storage mites "domestic mites". In addition to the respiratory allergic symptoms, the storage mites can also cause occupational contact dermatoses.