The Female dust mite can live for 70 days and in this time will lay 60 -100 eggs! Eww makes my skin crawl just thinking about it.

So its very likely that female dust mites could have been transported with all the eggs!.

I would recommend changing your sheets to hypo allergenic, cleaning regularly and choosing an air purifier that is good for allergies: http://air-purifier-reviewsite.com/blog/allergy-air-purifier/