Occupational sensitization to storage mites in the personnel of a water-damaged grocery store.

OBJECTIVES: To investigate the occupational exposure and sensitization to storage mites (SM) in sales staff working in a moisture-damaged and three healthy reference buildings. METHODS: The study population consisted of the entire personnel (n=12) in the moisture-damaged grocery store. They all suffered from persistent upper respiratory tract symptoms. Twelve (in results 11) symptom-free controls working in three healthy reference groceries were matched with age, sex and occupation. Dust samples from each building were examined for mites. The clinical study consisted of otorhinolaryngological examination and determination of IgE reactivity. Specific serum IgE antibodies were measured against three SMs and two house dust mites (HDM). Skin prick tests (SPT) were made to the same five mites and to five common aeroallergens. If sensitization to any of the SMs was detected, a nasal provocation test (NPT) was performed. RESULTS: SMs were found in all buildings. In all, seven cases and four control subjects showed IgE-mediated reactivity. Sensitization to mites was detected in six cases and in three controls and in 2/12 and 3/11 this was the only IgE antibody response observed. In addition, one case and one control subject were sensitized to common aeroallergens. NPT with SMs was positive in four cases and in one control. CONCLUSIONS: In grocery stores, the personnel are exposed to SMs. The risk of sensitization to mites is obvious and an IgE response can occur without any reactivity to common aeroallergens. SM allergy may in some cases explain the chronic rhinitis related to moisture-damaged buildings.

Exposure of workers to mites in Finnish groceries.

We assessed the mite exposure of workers in Finnish groceries by collecting samples of settled dust in 5 different grocerys. Mites were counted and identified microscopically. Mite allergen (Der p 1 and Der f 1) content of dust was analyzed with 2-site ELISA. Mites were found in 20-100 % of the samples, both from storage and salesrooms. Seven samples (8 %) contained more than 100 mites per gram dust and 3 additional samples (6 %) more than 500 mites per gram dust, the suggested limits for mite sensitization and acute allergic symptoms, respectively. Most of the mites were storage mites belonging to Astigmata (Acaridae, Glycyphagidae) or Prostigmata (tarsonemids). House dust mites were found only occasionally. One dust sample out of 15 contained Der p 1, and none contained Der f 1.

The efficacy of benzyl benzoate sprays in killing the storage mite Tyrophagus putrescentiae (Acari: Acaridae).

This study tested the effectiveness of benzyl benzoate (BB) in killing Tyrophagus putrescentiae (Schrank) mites when using the method utilized by regular consumers. The efficacy of the BB sprays was determined in laboratory experiments and semi-field experiments with mattress and mattress pad pieces. The mites were counted and their living status determined at different time points microscopically. In the laboratory experiment, the sprays containing either 0.5 %/0.9 % BB with 70 % ethanol or 0.1 % BB with absolute ethanol were highly efficient, resulting in over 90 % mite mortality within 20-30 minutes. In the semi-field experiment, mimicking the home application, the sprays were applied to pieces of a mattress and a mattress pad, and allowed to affect the area for 30 minutes before thorough vacuuming. The recovery of mites was usually less than 10 %. The sprays containing BB were effective in killing the mites in the laboratory, but success was less prominent in the semi-field tests. This method could be used in testing other compounds for their efficacy in killing mites.

Mites in facilities for laboratory animals.

OBJECTIVES: Two laboratory animal facilities were examined for storage and house-dust mites. METHODS: Samples of settled dust or material were investigated microscopically, and all of the found mites were identified. RESULTS: Every fourth sample contained mites. On the average, 86 mites were found in a gram of dust. Measurement with a two-way enzyme-linked immunosorbent assay revealed only one sample containing a minor amount of allergen from Dermatophagoides pteronyssinus. CONCLUSIONS: It seems that, in addition to house-dust mites, other mites may be important occupational contaminants in animal facilities.