PREVALENCE AND INFLUENCING FACTORS OF DEMODEX INFECTION AMONG COLLEGE STUDENTS IN ZHENGZHOU, PR CHINA

Abstract

Demodex spp are ectoparasites living in human hair follicles and sebaceous glands, and are considered to play a pathogenic role in facial dermatoses such as acne vulgaris.  This study investigated the prevalence and influencing factors of Demodex spp infection among college students in Zhengzhou, PR China.  College students (n = 500) were enrolled and a cellophane tape method was used to determine Demodex infection after students washed their faces with cool (n = 300) or warm water (n = 200).  Relevant factors were investigated by a questionnaire.  The positive detection rate was 38% and 26% for samples collected from students washing with warm and cool water respectively.  There is a significantly higher positive detection rate of Demodex foliculorum compared to D. brevis under both face washing conditions (χ2cool = 40.26, df = 1, p-valuecool <0.0001; χ2warm = 6.028, df = 1, p-valuewarm = 0.014).  The rate of Demodex infection is significantly higher for students with oily skin compared to dry or a combination of oily and dry skin (χ2warm =11.635, df =2, p-valuewarm = 0.003).  Our observations suggest that Demodex infection, particularly D. folliculorum, is fairly common among college students in Zhengzhou. Oily skin may increase susceptibility to Demodex infection, and washing the face with warm water before applying the cellophane tape method can improve the detection rate.