Objective: To analyze the epidemiological characteristics of dengue fever outbreaks in schools from Guangzhou in 2024, so as to provide a reference for formulating targeted prevention and control policies and measures. Methods: By using the National Infectious Disease Surveillance Information Reporting Management System to obtain information on dengue fever cases in Guangzhou from January 1st to December 31st, 2024. Descriptive data analysis was conducted on the temporal distribution, regional distribution, and school distribution of dengue fever outbreaks in schools. A mediation effect model was used to analyze the mediating effect of the time between onset and reporting between the type of school and the occurrence of recurrent cases. Results: In 2024,12.41% (385 cases) of dengue fever cases in Guangzhou involved schools, with 300 schools affected. Among these, 16 schools (5.33%) reported cluster outbreaks, and 24 schools (8.00%) reported secondary cases. The first dengue case at the school was reported at 26 July and the last case was reported at 4 December, the peak reporting period for cases was October 7 to November 3. The incidence of secondary cases in schools in central urban areas (5.19%) was lower than that in suburban schools ( 17.39 %), and the difference was statistically significant ( χ 2=9.15, P <0.01). The time from onset to reporting partially mediated the relationship between school type and the occurrence of recurrent cases ( β=0.23, P <0.05), accounting for 21.50% of the total effect. Conclusions Dengue fever is a key infectious disease facing schools in Guangzhou during summer and autumn. Surveillance of dengue fever outbreaks in schools should be strengthened during the peak season to reduce the risk of cluster outbreaks and the occurrence of secondary cases.

Periodontitis is a critical risk factor for the occurrence and development of diabetes.Porphyromonas gingivalis may participate in insulin resistance(IR)caused by periodontal inflammation,but the functional role and specific mechanisms of P.gingivalis in IR remain unclear.In the present study,clinical samples were analysed to determine the statistical correlation between P.gingivalis and IR occurrence.Through culturing of hepatocytes,myocytes,and adipocytes,and feeding mice P.gingivalis orally,the functional correlation between P.gingivalis and IR occurrence was further studied both in vitro and in vivo.Clinical data suggested that the amount of P.gingivalis isolated was correlated with the Homeostatic Model Assessment for IR score.In vitro studies suggested that coculture with P.gingivalis decreased glucose uptake and insulin receptor(INSR)protein expression in hepatocytes,myocytes,and adipocytes.Mice fed P.gingivalis tended to undergo IR.P.gingivalis was detectable in the liver,skeletal muscle,and adipose tissue of experimental mice.The distribution sites of gingipain coincided with the downregulation of INSR.Gingipain proteolysed the functional insulin-binding region of INSR.Coculture with P.gingivalis significantly decreased the INSR-insulin binding ability.Knocking out gingipain from P.gingivalis alleviated the negative effects of P.gingivalis on IR in vivo.Taken together,these findings indicate that distantly migrated P.gingivalis may directly proteolytically degrade INSR through gingipain,thereby leading to IR.The results provide a new strategy for preventing diabetes by targeting periodontal pathogens and provide new ideas for exploring novel mechanisms by which periodontal inflammation affects the systemic metabolic state.

OBJECTIVE To explore the pathogen distribution and their resistance in ICU of Geriatric hospital.METHODS 111 strains isolated from lower respiratory tract were collected from Sep 2006 to August 2007.The antibiotic resistance were tested.RESULTS Among 111 strains,G-strains accounted for 70.27%,in which Pseudomonas aeruginosa was the most common(20.72%).The G+bacteria were multi-resistant to most of the antibiotics except impenem.CONCLUSIONS The most common pathogens in ICU of geriatric hospital is G-bacteria with multi-resistance.The Antibiotics should be selected reasonably.