House dust mites in Williamsburg, Virginia.

House dust allergy is a common medical ailment. It has been well established that mites of the genus Dermatophagoides (house dust mites) are an important source of allergens and that mite counts greater than 300 per gram of dust are associated with symptoms of asthma. A survey of 22 houses in Williamsburg, Virginia, during the month of August revealed that all had mite populations exceeding this number. This may explain in part the high incidence of allergy in the Williamsburg area.