ObjectiveTo conduct an epidemiological investigation and analysis of a clustered scabies outbreak in a middle school, so as to provide evidence for developing targeted prevention and control strategies. MethodsCase data on a clustered scabies outbreak occurring in a middle school of Shaanxi Province in 2025 were collected. Field epidemiological approaches were adopted to define cases, search for infected individuals, and describe the temporal, spatial, and population distribution. Specimens were collected from individuals and surrounding environments for laboratory testing. ResultsA total of 25 scabies cases were identified in 4 classes and 9 dormitories of the school. All cases were first-year high school students. The overall attack rate was 6.00% (25/414); the attack rate was 10.53% (22/209) among male students and 1.46% (3/205) among female students. The disease course ranged from 10 to 30 days, with a median duration of 14 days, and 3 students (12.00%) continued attending classes with ongoing infection. Skin scrapings collected from lesion sites of 3 patients were examined under microscopy, all of which were positive for Sarcoptes scabiei; no laboratory testing was performed for the remaining cases. This clustered scabies infection outbreak lasted for one month. All affected students recovered completely without severe complications or deaths, and the outbreak was effectively contained. ConclusionThis scabies infection is a clustered school-based scabies outbreak caused by Sarcoptes scabiei. Affected patients present relatively severe symptoms and a prolonged disease course. Scientific and standardized preventive systems should be established to enable timely early warning and emergency response.

Objective To evaluate preventive effect of polysaccharides from Lycium ruthenicum Murray against photodamage in HaCaT cells,and to explore its possible mechanism.Methods Ultrasoundassisted extraction was used to extract polysaccharides from Lycium ruthenicum Murray in Qaidam Basin.In vitro cultured HaCaT cells were randomly divided into 3 groups:control group receiving no treatment,ultraviolet B (UVB) group irradiated with 30 nJ/cm2 UVB alone for 1 hour,experimental group pretreated with 2 g/L Lyeium ruthenicum polysaccharide solution followed 6 hours later by 30 mJ/cm2 UVB radiation for 1 hour.At twelve hours after UVB radiation,an inverted microscope was used to observe cell morphology.Then,MTS assay was performed to estimate cell proliferation,flow cytometry to detect cell apoptosis,an enzyme-labeled antigen method to detect levels of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px),as well as to evaluate the activity of superoxide dismutase (SOD) and catalase (CAT),and enzyme-linked immunosorbent assay (ELISA) to measure levels of intedeukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α) in HaCaT cells and their culture supernatant.Results Compared with the control group,the UVB group showed obscure cell morphology,cell death and floating phenomenon,while cells became swollen but renained morphologically distinct in the experimental group.MTS assay revealed that the cell proliferative activity significantly differed among the above 3 groups (F =48.88,P ＜ 0.01),and the cell proliferative activity was significantly lower in the UVB group (1.72 ± 0.12) than in the control group (2.34 ± 0.11,P ＜ 0.05) and experimental group (2.11 ± 0.10,P ＜ 0.05).Moreover,the apoptosis rate was significantly higher in the UVB group (82.41％ ± 2.49％) than in the control group (3.98％ ± 0.19％,P ＜ 0.05) and experimental group (22.79％ ± 0.97％,P ＜ 0.05),as well as higher in the experimental group than in the control group (P ＜ 0.05).Compared with the control group,the UVB group showed significantly higher levels of MDA,supernatant levels of IL-1 and TNF-α,and intracellular levels of TNF-α,but significantly lower GSH-Px levels and activity of SOl and CAT (all P ＜ 0.05).However,there was no signifi-cant difference in the intracellular level of TNF-α between the UVB group and control group (P ＞ 0.05).Conclusion Lycium ruthenicum polysaccharide has protective effects against photodamage in HaCaT cells,likely by reducing the synthesis and secretion of inflammatory substances as well as free radicals.