The effect of seasonal and domestic factors on the distribution of Euroglyphus maynei in the homes of Dermatophagoides pteronyssinus allergic patients

Abstract

Summary A survey of the house dust mite population was carried out in the homes of fifty asthmatic Liverpool individuals with strongly positive skin tests to Dermatophagoides pteronyssinus. As expected, D. pteronyssinus was the commonest species found. However, Euroglyphus maynei made up 37% of the total adult mite count and was the predominant species in 48% of beds examined. There was a good correlation between increasing numbers of E. maynei and decreasing social class, but only a weak one with percentage relative humidity. Ionic sodium levels in bed dust were found to correlate with decreasing social class and increasing E. maynei levels. In nineteen beds, mites were sampled at 4‐monthly intervals for 1 year—this showed a relative decrease in the proportion of E. maynei compared with other mites in the autumn, when relative humidity was high. A further twenty beds underwent intensive house dust eradication (including the use of plastic covers) for 1 year—these beds showed a progressive fall in the proportion of E. maynei recovered, suggesting that this mite is more vulnerable to anti‐house dust mite measures. Euroglyphus maynei is a common house dust mite and further work needs to be done to assess its antigenic nature and clinical significance.

A review of biology and allergenicity of the house-dust miteEuroglyphus maynei (Acari: Pyroglyphidae)

“…A significant correlation between increasing density of E. maynei and decreasing social class of the patients was found by Walshaw and Evans ( 1987 ), and also between decreasing social class and increasing ionic sodium concentrations (used by them as an index of sweat input) in the beds. They suggested that individuals in lower social classes may perspire more than those with professional, non-manual jobs, and that high 'sodium load' may favour development of large E. maynei populations.…”

“…However, the validity of the sex-ratio imbalance commented on by these authors remains open to question since it was, in each case, calculated from the numbers of mites extracted from dust samples rather than based on in vitro observations. Walshaw and Evans (1987) commented that the sex-ratio imbalance was more likely due to human error during sorting mites from dust samples; the smaller-sized males were missed more often than the larger females.…”

“…Carswell et al ( 1982 ) likewise found lower densities in overblankets and pillows than in mattresses and soft toys. Walshaw and Evans (1987) found E. maynei present in 80% of beds and numerically dominant in 48%, representing 37% of the total house-dust mite population in homes of asthmatics in Liverpool, England. It constituted 25% of the population on bedroom floors and 18% on lounge carpets.…”

“…Walshaw and Evans ( 1987 ) provide some limited information, stating that E. maynei numbers were lowest 'in the Autumn' (i.e., August-October). Carswell et al (1982) indicated an increase in E.…”

Population Growth and Allergen Content of Cultured <b><i>Euroglyphus maynei</i></b> House Dust Mites

“…E. maynei frequently co-inhabits with D. farinae and D. pteronyssinus in some geographical areas, and in some instances E. maynei may be the more abundant species [1][2][3][4][5][6][7][8][9][10][11][12] . Many dust mite allergic patients are skin test positive to all 3 species of these mites [13][14][15][16] .…”