Avaliação da acarofauna em ecossistemas domiciliares do município de Porto Alegre/RS, Brasil

Abstract

House dust mites are the main sources of aeroallergens in the world and are the main triggers of allergic diseases such as asthma and rhinitis. Few studies have analyzed house dust mites from populations from developing countries. The aim of our study is to assess the prevalence of house dust mites, comparing two economically distinct populations: a high-income and a low-income group. Samples were collected between July and December of 2015, in city of Porto Alegre, Brazil. House dust was collected in the living room (floor, couch and carpet) through a home vacuum cleaner (1,500 Watts). The dust samples were then analyzed through a stereomicroscope. The identification of mites was performed through optical microscopy by dichotomous keys. One hundred and four homes were visited (low income group, n=53; high income group, n=51). The low-income group had a low education index, usually with only two rooms, no windows, and no basic sanitation. The presence of domestic animals and ventilation inside the homes from low-income group were significantly high, compared to the high-income group. A total of 721 mites were detected, in 89% of the houses visited, belonging to 11 species. There were no significant differences between the prevalence of mites among the groups studied. However, the low-income group showed a higher number of mites per house studied compared to the high-income group (p<0.001). Dermatophagoides pteronyssinus was the predominant species detected (39.6%), followed by Euroglyphus maynei and Tyrophagus putrescentiae, in both groups studied. Dermatophagoides farinae was not found in any house visited. In conclusion, house dust mites exist in different niches worldwide, with prevalence rates and characteristics that may vary geographically and socially, that are dependent on environmental factors, such as light, humidity, and temperature.