Prevalence of Ocular Demodex Infestation in Children: An Epidemiological Survey in South China

Abstract

Objectives: To investigate the prevalence of and risk factors for Demodex mite infestation of the eyelashes in Chinese children. Methods: A total of 1,575 children were surveyed from June 2017 to January 2019 and stratified into two age groups: 3 to 6 and 7 to 14 years. All subjects underwent routine eye examination and lash epilation for Demodex mite identification and counting using microscopy. Demographic data and lifestyle habits were also recorded. Results: Demodex mites were detected in 189 of 1,575 (12.0%) children, including Demodex folliculorum (D. folliculorum) in 180 (11.4%), Demodex brevis (D. brevis) in 11 (0.7%), and both mites in 2 (0.1%). The median number of D. folliculorum mites was 1 (interquartile range [IQR], 1–2) and that of D. brevis was 1 (IQR, 1–1). Children with Demodex infestation did not exhibit more ocular discomfort than those without (21.2% vs. 23.1%; P=0.56). However, lash abnormalities, including trichiasis, cylindrical dandruff, or scaly discharge at the lash root, were more prevalent in children with Demodex infestation (24.9% vs. 12.8%; P<0.001) and in the 7 to 14-year subgroup (33.7% vs. 12.8%; P<0.001). Multiple logistic regression revealed that autumn–winter was associated with a higher detection rate of Demodex infestation (all P<0.05). In the 3-6-year subgroup, children residing in rural regions exhibited a higher prevalence of Demodex infestation (P=0.03). Conclusions: Ocular Demodex infestation, with a low Demodex mite count, was found in healthy Chinese children aged 3 to 14 years.

Age differences in ocular demodicosis: Demodex profiles and clinical manifestations

“…In the present study, it can be clearly seen that the young group had a higher prevalence of corneal changes involving the stroma, such as infiltration or ulceration, while SPK was the main corneal change in elderly people. Our previous research and the findings in this study provide strong support to D. brevis or D. brevis % as a risk factor for corneal changes in young patients with ocular demodicosis (13)(14)(15). This study revealed that there are relatively fewer D. brevis mites and milder corneal changes in elderly patients, which further supports our notions that D. brevis plays a more important role in the pathogenesis of ocular demodicosis.…”

“…To the best of our knowledge, this was the first time that Demodex infestation was detected in children without systemically immunocompromised status. Recently, we conducted an epidemiological survey and revealed a low Demodex mite count in 12.0% of healthy Chinese children aged between 3 and 14 years (14).…”

“…To mitigate the concern that the demodex infestation is age-related and much more prevalent in the elders, our previous studies focussed on young patients and found a high prevalence of keratitis (14,15). Ahmad also reported 6 cases of keratopathy in patients with Demodex infestation, 2 of whom were under 35 years (9).…”

Dermatoparasitoses in Referral Patients to the Laboratory

“…In South China in 2021, the incidence of eye infections due to Demodex spp. was significantly higher in autumn and winter than in other seasons amongst 1,575 school-children (43). Apparently, there is consensus in the literature that Demodex spp.…”

Ivermectina para Demodex folliculorum. Un estudio <i>in vitro</i>

“…La blefaritis por Demodex folliculorum es una condición común que afecta casi al 100% de las personas mayores de 70 años 1 . Puede también afectar a niños aunque la incidencia es menor (alrededor del 15%) 2 . La presencia de Demodex folliculorum se ha asociado en los últimos años a un número importante de condiciones oculares como síndrome de ojo seco 3 , disfunción de glándulas de Meibomio 4 , rosácea cutánea 5 y ocular, chalazión recurrente 6 , meibomitis 7 , querato-conjuntivitis 8 y neovascularización de la córnea 9 .…”