HOUSE DUST MITES OF MATTRESSES IN SINGAPORE : DISTRIBUTION & EFFECT OF BEDKEEPING HYGIENE

Abstract

This s tudy, the first of its nature in Singapore, set out to document the mite species present locally in mattress dust. This was done by identifying the species of mites occurring in dust samples from various collections. A study was also made of the mite distribution within different dwelling types. Dust samples were collected from homes, a hotel and a hospital. The mite distribution was related to the bedkeeping hygiene practised in the three dwelling types. Eleven species of mites were found. The most common one was Blomia tropicalis; it was dominant in homes, while another mite, Dermatophagoides pteronyssinus, was the most abundant one in the hotel and hospital samples. The hospital samples yielded the least number of mites and the homes, the most. It was found that the practices of pesticide application, use of plastic encasings and high frequency of mattress cleaning, occuring in the hospital, were associated with low mite numbers. In Part II of the study, it was found experimentally that a higher frequency of bedsheet change did not affect mite count.