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Dust Mite Lure
Although there are many methods of house dust mite control, they are not without their limitations. Synthetic chemical acaricides found in commercially available products, can be used to control house dust mites by applying them to house dust mite habitats (carpets, mattresses, soft furnishings). Permethrin can be impregnated on to mattress-liners, and a clinical trial demonstrated success at controlling house dust mites for at least 27 months. Acaricides need to be regularly applied, otherwise re-colonisation of mites will occur, either due to ovicidal activity or due to a lack of penetration of treatments deep inside the furniture. Furthermore, many asthmatic patients are reluctant to use these products, especially in dormitory areas. Environmental methods which have undergone experimental trials in an attempt to reduce mite populations include the use of sub-floor heating, steam cleaning, freezing soft toys and washing clothes and bed linen above 55°C. Humidity below 51% has been shown in experimental trials to significantly reduce mite and allergen levels. Regular vacuum cleaning can reduce the allergen reservoir on beds and carpets but vacuum cleaners can release house dust mite allergen into the air from the vacuum. Clinical trials have shown a range of efficacy in using impermeable bed-covers to alleviate symptoms of atopic disease but some patients found them Semiochemicals (behaviour-modifying chemicals) have the potential to be used to manipulate house dust mite behaviour, and offer a natural, alternative method to controlling these medically important arthropods. The inventor has identified house dust mite semiochemicals and developed a lure-and-kill strategy for mite control. The invention has the potential to draw mites from deep inside the furniture and mattresses, where upon they would become exposed to a naturally produced acaricide and subsequently vacuumed. Atopic diseases such as asthma are a growing public health problem in the UK, as well as other developed countries such as Australia, New Zealand and USA. Dermatophagoides pteronyssinus (Trouessart) (European house dust mite) and D. farinae (Hughes) (American house dust mite) are found throughout the developed world and are known to excrete allergens that cause atopic diseases. The invention comprises the use of neryl formate and/or limonene as a lure or an attractant for house dust mites. Neryl formate, also known as (Z)- 3,7-dimethyl-2,6-octadienyl formate, is a semiochemical obtained from house dust mites. The limonene in the composition is preferably in the form of the R-(+)- enantiomer. The invention may additionally include the step of exposing the house dust mites to an acaricide, such as natural pyrethroids and essential oils. One particular acaricide that may be used is pyrethrum. Preferably, the dust mites are exposed to the acaricide simultaneously or subsequently to exposure to the neryl formate and/or limonene. The composition is expected to be particularly effective with Dermatophagoides pteronyssinus, the European house dust mite, and Dermatophagoides farinae, the American house dust mite. Normally dust mites cling to fibres in, for example, carpets, mattresses and pillows and cannot easily be removed. When the neryl formate and/or limonene composition is placed near to house dust mites, they are attracted to the composition and are drawn towards the surface of the carpet or piece of furniture, from where they can be more easily removed e.g. by The composition may be produced in powder form by, for example, formulating the neryl formate and/or limonene into a wax and then into particles. This allows it to be easily dusted or shaken over a carpet or item of furniture that may contain dust mites. In many instances, a preferred means of forming a powder formulation is to prepare granules. These may be prepared, for example, by mixing the neryl formate with a diluent powder and a small amount of binder so as to form a moist mass, coarse screening the mass, drying the resulting moist granules, screening the dried granules and optionally mixing with a glidant. It may be preferable in some circumstances for the neryl formate or limonene to be formulated into a powder product which is suitable for sprinkling. This may be achieved by simple mixing of a small amount of the neryl formate with suitable inert powders. Alternatively, the neryl formate may be made into a suspension/emulsion together with an amphipathic carrier (e.g. a modified starch) in an aqueous medium. The suspension/emulsion may then be spray dried, the product of which is a dustable powder containing neryl formate partially or completely encapsulated within the carrier. The composition may be provided in container provided with a nozzle, such as a misting or aerosol nozzle, through which the composition may be driven. The composition may be driven through the nozzle by a pump or any other This patent is jointly owned by Rothamsted Research and the London School of Hygiene and Tropical Medicine. The patent is pending in Europe, China, Brazil, Australia, Canada, India, Japan and USA and has been granted in New Zealand, South Africa and Singapore. The patent is available for licencing. Know-how licensing and consultancy opportunities also exist. Licensing
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Source: http://www.rothamsted.ac.uk/sites/default/files/attachments/2013-10-09/Rothamsted%20Research%20-%20Patent%20168%20-%20Dust%20mite%20lure.pdf