Raquel Soares Binotti

House dust mites in Brazil - an annotated bibliography

House dust mites have been reported to be the most important allergen in human dwellings. Several articles had already shown the presence of different mite species at homes in Brazil, being Pyroglyphidae, Glycyphagidae and Cheyletidae the most important families found. This paper is an annotated bibliography that will lead to a better knowledge of house dust mite fauna in Brazil.

Comparison of house dust mites found on different mattress surfaces

BACKGROUND House dust mites have been considered the most important source of allergens for humans. These allergens have been encountered at different indoor sites, mainly on mattresses and pillows. OBJECTIVE To evaluate the number and different specimens of mites on Brazilian bunk-bed mattresses. METHODS Dust samples were collected once using a standardized method on the upper mattress surface (US) and lower mattress surface (LS) (bed frame also included in the latter) of 58 mattresses. RESULTS The total number of mite bodies on the LS was 3.5-fold higher than on the US, with a mean concentration of 932 mites per gram of fine dust (mites/g) on the US (range, 0-3,375 mites/g) and 3,254 mites/g on the LS (range, 125-14,500 mites/g) (P < .001). Additionally, the number of house dust mite bodies on the LS was 2.4 higher than on the US (P < .001); the mean concentration was 750 mites/g on the US (range, 0-2,875 mites/g) and 1,816 mites/g on the LS (range, 0-10,875 mites/g). Approximately 91% (n = 52) of the US and all LS dust samples had more than the limit of 100 mites/g. The most frequent family was Pyroglyphidae in both mattress surfaces, with Dermatophagoides pteronyssinus the most important species found. Storage mites, including Glycyphagidae (P < .001), Acaridae (P < .001), and other families (P < .001), also showed significant differences in the number of mites between both sample counts. CONCLUSIONS This study shows a significant difference in US and LS mite counts, with higher counts on the LS. Mite allergen avoidance should include the LS and bed frame as potential targets.

Mites in dust samples from mattress surfaces from single beds or cribs in the south Brazilian city of Londrina

The aim of this study was to investigate the mite fauna in mattresses dust samples from cribs or beds in the south Brazilian city of Londrina, State of Paraná. A total of 133 dust samples from upper and lower mattress surfaces, and bed frames were aspirated once from 38 dwellings (18 cribs and 21 beds), and one day nursery (six cribs). A total of 758 mite bodies were counted in slides: 233 (30.7%) from cribs and 525 (69.3%) from beds (p < 0.001). House dust mites – mainly Dermatophagoides pteronyssinus, represented 72% and 84% of total mite count in crib and bed dust samples, respectively. The mean HDM body concentration in crib or bed slides were, respectively, 289.9 ± 136.7 and 875.0 ± 183.6 mites/g. Statistical analysis showed a significantly higher mite bodies count on lower mattress surface compared with upper surface in bed samples only (p = 0.025). Data herein show that cribs like mattress have sufficient mite bodies to cause sensitization to humans. The use of mattress covers for cribs and beds should be encouraged in order to avoid allergens exposure.

Survey of acarine fauna in dust samplings of curtains in the city of Campinas, Brazil

The aim of this study was to investigate the mite fauna present in 33 living room and 22 bedroom curtain dust samples from 41 different homes in the southern Brazilian city of Campinas, SP. A total of 148 mite bodies were found. Of these, 83 were found in living-room curtain samples (56.1% of total) and 65 were in bedroom curtain dust samples (43.9%). The most frequently observed mite suborders were: Acaridida (n = 79; 53.4%), Actinedida (n=53; 35.8%), Oribatida (n=14; 9.5%), and Gamasida (n=2; 1.3%). The most frequent families were Pyroglyphidae (n=61; 41.2%), Eriophyidae (n=25; 16.9%), Tarsonemidae (n=15; 10.1%), and Glycyphagidae (n=13; 8.8%). No statistical difference was observed between the number of mites found in the samples from living room and bedroom curtains.