Abundance of house dust mites in relation to climate in contrasting agricultural settlements in Israel

Abstract

The correlation between climatic conditions and mite numbers in houses from rural areas was studied in 13 agricultural communities (kibbutzim and moshavim) in nine geo-climatic subregions of Israel. Mites were present in 97% of the dust samples. The average number of mites per gram of dust in the different localities ranged between 84 and 2053. The maximum number of mites (7440/g dust) was found in a carpet from a house in Geva Carmel in the northern coastal region. The most prevalent species of mites were Dermatophagoides pteronyssinus and Dermatophagoides farinae, which were found in 85.6% and 71.3% of the samples, respectively. The house dust mites D. pteronyssinus, D. farinae and Euroglyphus maynei constituted 94.8% of the mites. Most of the mites were isolated from the carpets and sofas (37.0% and 33.7%, respectively), and a smaller number from beds (29.3%). The smallest number of mites (< or = 250/g dust) were found at a minimum relative humidity (RH) of 30% and lower, with a maximum temperature of 32 degrees C and higher, i.e. in the Jordan valley and Negev mountains. A greater number of mites (250-500/g dust) were found at a minimum ambient RH of 35-40% and a maximum temperature of 32 degrees C and higher, i.e. the Hula valley. A large number of mites (500-1000/g dust) were found at a minimum RH of 35-40% with a maximum temperature of 30 degrees C and lower, i.e. in the Judean and Samarian range, as well as in upper Galilee. The largest number of mites (1000-2000/g dust) was found at a minimum RH of 45% and higher, with a maximum temperature ranging between 30 and 32 degrees C. These conditions occur in the coastal strip, the coastal plain and in the Judean and Samarian foothills. A monthly examination of two houses in Zova, a kibbutz in the Judean hills next to Jerusalem, and two houses from Palmachim, a kibbutz in the coastal region, revealed that the highest prevalence of mites was found in the months April-November and May-November, respectively. In Zova, the highest number of mites were found during the months of June and July while the highest concentrations of D. pteronyssinus-antigen (Der p I) were measured during the month of September. A positive correlation between mite numbers and the quantity of Der p I in house dust was found.

Determinación de ácaros del polvo en 90 hogares de tres localidades de Bogotá, Colombia

“…Por especie, el ácaro predominante en todas las muestras fue el Dermatophagoides pteronyssinus en el 71,32% de las muestras de Ciudad Bolívar, en el 69,66% de las muestras de Rafael Uribe Uribe y en el 75% de las muestras en San Cristóbal. Estos resultados son similares a lo reportado por Muncuoglu et al [17], según los cuales la especie más frecuente en muestras de ácaros de alfombras, camas y sofás fue el Dermatophagoides pteronyssinus en el 85,6% de las muestras.…”

“…Por lo tanto, también es evidente que la almohada presente un mayor promedio de ácaros, ya que si están presentes en el colchón, pueden trasladarse (migrar) a la almohada, donde están en mayor contacto con las vías aéreas y, por ende, asociados con el posible desencadenamiento de enfermedades alérgicas, respiratorias y dermatológicas. Sin embargo, Muncuoglu et al [17], en su estudio, reportan que los lugares más frecuentes donde se encuentran los ácaros son los sofás (33,7%) y las alfombras (37%), pues son lugares donde más polvo se acumula, y en menor grado, la cama (29,3%).…”

House Dust Mites, Other Domestic Mites and Forensic Medicine

“…The relatively low frequency of mites in a total of samples from dwellings examined and relatively lower abundance of glycyphagids, acarids, cheyletids and E. maynei mites is clear, taking into account the aforementioned values of indoor relative humidity observed in these dwellings (Fain et al, 1990;Solarz, 1998Solarz, , 2003. In general, these mites are not as abundant or frequent in Europe as in the Tropics (Fain et al, 1990;Puerta et al, 1993;Mehl, 1998;Mumcuoglu et al, 1999;da Silva et al, 2001;Colloff, 2009). The mean concentration of mites in examined samples and mite frequency was at the lower end of the published range for more humid regions ( Van Bronswijk, 1981;Fain et al, 1990;Mumcuoglu, et al 1999;Colloff, 2009) and was comparable with some European results from France, Denmark and Holland ( Van Bronswijk, 1981;Fain et al, 1990;Harving et al, 1993) and with other results from Poland (Horak et al, 1996;Racewicz, 2001).…”

“…In the case of mite density, the number of mites per gram of dust may range from a few to 16,000 or more, although the results of the surveys are difficult to compare and evaluate because of the lack of standardization of both dust collecting methods and reporting procedures. It has been shown, however, that occurrence and abundance of house dust mites may vary in particular topographical regions and are associated to a large degree with the climate of a region, and especially with outdoor and indoor humidity (Korsgaard, 1998;Mumcuoglu, 1976;Mumcuoglu et al, 1999;Colloff, 2009). Ratios of numbers of the particular pyroglyphid dust mite species, especially between D. pteronyssinus and D. farinae, are different in separate regions of the world (Fain et al, 1990;Mumcuoglu, et al 1999).…”

“…It has been shown, however, that occurrence and abundance of house dust mites may vary in particular topographical regions and are associated to a large degree with the climate of a region, and especially with outdoor and indoor humidity (Korsgaard, 1998;Mumcuoglu, 1976;Mumcuoglu et al, 1999;Colloff, 2009). Ratios of numbers of the particular pyroglyphid dust mite species, especially between D. pteronyssinus and D. farinae, are different in separate regions of the world (Fain et al, 1990;Mumcuoglu, et al 1999). Decisive factors influencing their occurrence and abundance are mainly relative humidity and temperature of both outdoor and indoor air (Solarz, 2001 a, b).…”