title: 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.
authors.affiliation: Department of Parasitology, Hebrew University-Hadassah Medical School, Jerusalem, Israel. kostam@cc.huji.ac.il
authors.forename: K Y
authors.initials: KY
authors.lastname: Mumcuoglu
authors.forename: Z
authors.initials: Z
authors.lastname: Gat
authors.forename: T
authors.initials: T
authors.lastname: Horowitz
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: R
authors.initials: R
authors.lastname: Bar-Tana
authors.forename: A
authors.initials: A
authors.lastname: Ben-Zvi
authors.forename: Y
authors.initials: Y
authors.lastname: Naparstek
mesh_terms: D000383:Agriculture; D000818:Animals; D002980:Climate; D006801:Humans; D007557:Israel; D008925:Mites / Q000145:classification; D011156:Population Density; D012621:Seasons