Epidemiological characterization of pityriasis versicolor and distribution of Malassezia species among students in Hai Phong city, Vietnam

Background and Purpose: Pityriasis versicolor (PV) is a common fungal skin infection caused by Malassezia species. Previous studies have shown that the prevalence of PV is influenced by geographic factors. The aim of the current study was to find the epidemiological characteristics of PV and distribution of Malassezia species in the secondary school students living in Hai Phong city, Vietnam. Materials and Methods: This study was conducted on ۱۳۵۷ students within the age range of ۱۰ - ۱۶ years selected from four secondary schools in Hai Phong city. The students were screened for PV skin lesions from August ۲۰۱۶ to December ۲۰۱۷. The isolates of Malassezia from PV patients were analyzed by performing direct microscopy and culturing on modified Dixon agar plates, containing gentamicin, at ۳۲oC for ۷ days. In the next stage, the fungal strains obtained from patients with positive fungal cultures were identified using the CHROMagarTM Malassezia medium, polymerase chain reaction-restriction fragment length polymorphism techniques, and D۱/D۲ rDNA genome sequencing. Results: Pityriasis versicolor was diagnosed in ۳۰۵ (۲۲.۴۸%) students and confirmed by clinical appearance and direct examination. A total of ۲۹۳ (۹۶.۰۷%) samples grew on modified Dixon agar. With regard to demographic characteristics, ۵۰.۴۹% of the PV cases were female, and ۵۷.۳۸% of cases resided in urban areas. Furthermore, ۸۸.۵۲% of the subjects had the illness duration of more than ۶ months. Hypopigmented and erythematous skin lesions were also observed in the research participants, with hypopigmentation being the most frequent condition (۹۷.۰۵%). Most of the Malassezia fungal strains were isolated from the back (۳۹.۵۶%), face (۲۳.۹۹%), and chest (۱۶.۵۱%). Malassezia furfur and M. japonica accounted for PV in ۹۶.۲۵% and ۳.۷۵% of the cases, respectively. Furthermore, Malassezia furfur was distributed in both rural and urban areas, while M. japonica was found only in the urban areas. Conclusion: The findings of the present study were indicative of the high prevalence of Malassezia yeasts, mostly M. furfur, among the students in Hai Phong city, Vietnam for print

کلیدواژه ها:

Hai Phong city ، Malassezia ، Pityriasis versicolor ، Students ، Vietnam