Objective: To analyze the epidemiological characteristics and trends of other infectious diarrhea among children under 18 years old in Guangzhou City from 2014 to 2020, and to explore the correlation between climatic factors and the incidence of the disease, so as to provide reference for the early prevention of infectious diseases. Methods: The data of cases of other infectious diarrhea and meteorological data of children under 18 years old in Guangzhou City from 2014 to 2020 were collected through the Chinese Infectious Disease Reporting System and the Guangzhou Meteorological Bureau. The correlation between meteorological factors and the incidence of other infectious diarrhea was analyzed using negative binomial regression. Results: A total of 104 566 cases of other infectious diarrhea among children under 18 years old were reported in Guangzhou City from 2014 to 2020, with a male to female ratio of 1.48∶1. The incidence rate was the highest in 2017 (980.83 per 100 000) and the lowest in 2020 (388.22 per 100 000). The peak of incidence occurred from October to March of the following year. Children under 5 years old accounted for 87.95% of all cases. The number of cases of other infectious diarrhea was negatively correlated with the temperature of the previous 6 days ( IRR = -0.07 ), and positively correlated with the temperature difference on the day of onset ( IRR =0.02) (both P <0.05). It was also positively correlated with the wind speed of the previous 7 days ( IRR=0.07, P <0.05), but there was no statistically significant correlation with the relative humidity on the day of onset ( IRR=-0.00, P >0.05). Conclusions Low temperature, large temperature difference, and high wind speed can increase the risk of other infectious diarrhea. It is necessary to strengthen the prediction and early warning in conjunction with meteorological changes, and warn kindergartens and schools to enhance preventive measures against the clustering of other infectious diarrhea cases.

Objective:To identify a novel reassortant H3N2 avian influenza virus using nanopore sequencing technology and analyze its genetic characteristics.Methods:The positive samples of the H3N2 avian influenza virus, collected from the external environment in the farmers' market of Guangzhou, were cultured in chicken embryos. The whole genome was sequenced by targeted amplification and nanopore sequencing technology. The genetic characteristics were analyzed using bioinformatics software.Results:The phylogenetic trees showed that each gene fragment of the strain belonged to the Eurasian evolutionary branch, and the host source was of avian origin. The HA gene was closely related to the origin of the H3N6 virus. The NA gene was closely related to the H3N2 avian influenza virus from 2017 to 2020. The PB1 gene was closely related to the H5N6 avian influenza virus in Guangxi Zhuang Autonomous Region and Fujian Province from 2016 to 2022 and was not related to the PB1 gene of the H5N6 avian influenza epidemic strain in Guangzhou. The other internal gene fragments had complex sources with significant genetic diversity. Molecular characteristics indicated that the strain exhibited the molecular characteristics of a typical low pathogenic avian influenza virus and tended to bind to the receptors of avian origin. On important protein sites related to biological characteristics, this strain had mutations of PB2-L89V, PB1-L473V, NP-A184K, M1-N30D/T215A, and NS1-P42S/N205S.Conclusions:This study identified a novel reassortant H3N2 avian influenza virus by nanopore sequencing, with the PB1 gene derived from the H5N6 avian influenza virus. The virus had a low ability to spread across species, but further exploration was needed to determine whether its pathogenicity to the host was affected.

Objective:To explore the construction of a competency-oriented off-campus practice training system for master of public health (MPH).Methods:Through literature review and analysis on domestic and foreign MPH degree training models, a comprehensive and feasible MPH off-campus practice training system was designed innovatively.Results:The construction of a "4+N+Comprehensive Evaluation" practice system for MPH programs with a practice duration of more than 2 years has been explored by high-level public health talent training demonstration base of Sun Yat-sen University-Guangzhou CDC. "4" represents practice-based teaching, professional practice, participation in public health project management, and research for the training of MPH in terms of theory, practice, management and research anility of public health. "N" represents expanded practice to train MPH with comprehensive competence and professional spirit," and comprehensive evaluation is used to assess the training effect.Conclusion:A competency MPH off-campus practice system of "4+N+Comprehensive Evaluation" has been established for the training of high-level public health professionals in new era.

To monitor and analyze the molecular variation of the H3N2 influenza virus in Guangzhou during the COVID-19 pandemic, respiratory samples of influenza-like cases from influenza monitoring sentinel hospitals were collected from influenza monitoring sentinel hospitals for virus isolation and whole genome sequencing. The results showed that during COVID-19, there was only one peak of H3N2 influenza in the second quarter of 2022 in Guangzhou (the positive rate was 52.23%), and the epidemic intensity and duration were both higher than those in 2019. The HA gene and NA gene of the epidemic strain in Guangzhou in 2022 belonged to the 3C.2a1b. 2a. 1a. 1 branch, which had a good antigenic site matching with the vaccine strain (A/Cambodia/e0826360/2020) from 2021 to 2022 and had no antigen drift. In 2022 strains, the variation of antigen determinant mainly occurred in the I48T of C region, while no variation occurred in the A, B, D, and E regions. The binding site of the HA protein receptor was consistent with the vaccine strain (A/Cambodia/e0826360/2020). Most of the strains in 2022 carried 13 glycosylation sites on the HA protein, but an outbreak of strains caused a loss of glycosylation sites at 24-NST. In conclusion, the strains that caused the epidemic of H3N2 influenza in Guangzhou in 2022 were not evolved or transmitted from the local strains in 2019 during the COVID-19 pandemic.

Objective:To establish a rapid pipeline for whole genome sequencing of Chikungunya virus (CHIKV) by combining imbricated multiplex-PCR amplification and Illumina high-throughput sequencing platform.Methods:The primary reference sequences of CHIKV were downloaded from the National Center for Biotechnology Information (NCBI) database, covering all genotypes of CHIKV. After multiple alignments using the Mafft software and phylogenetic analysis, the 20 CHIKV references were selected for primer design. The Primal Scheme tool and Geneious Prime software were used to design, evaluate and optimize the primer panel. Finally, seven CHIKV-positive samples were involved in the validation of the primer panel.Results:All the amplicons of the designed panel were generated successfully. The consensuses generated from the mapping results could cover 100.00% of the coding region of the CHIKV genome when the Ct-value of the sample was less than 33, as the percentage would decrease to 99.38% when the Ct-value reached 35. The mapping percentage could be increased by 5.70%-25.43% when using the stepwise correction mapping strategy.Conclusion:The multiplex-PCR amplification method for CHIKV whole genome sequencing is relatively simple and convenient, which only requires two tubes of PCR amplification and performs well on CHIKV-positive clinical samples with different concentration levels of virus.

To monitor and analyze the molecular variation of the H3N2 influenza virus in Guangzhou during the COVID-19 pandemic, respiratory samples of influenza-like cases from influenza monitoring sentinel hospitals were collected from influenza monitoring sentinel hospitals for virus isolation and whole genome sequencing. The results showed that during COVID-19, there was only one peak of H3N2 influenza in the second quarter of 2022 in Guangzhou (the positive rate was 52.23%), and the epidemic intensity and duration were both higher than those in 2019. The HA gene and NA gene of the epidemic strain in Guangzhou in 2022 belonged to the 3C.2a1b. 2a. 1a. 1 branch, which had a good antigenic site matching with the vaccine strain (A/Cambodia/e0826360/2020) from 2021 to 2022 and had no antigen drift. In 2022 strains, the variation of antigen determinant mainly occurred in the I48T of C region, while no variation occurred in the A, B, D, and E regions. The binding site of the HA protein receptor was consistent with the vaccine strain (A/Cambodia/e0826360/2020). Most of the strains in 2022 carried 13 glycosylation sites on the HA protein, but an outbreak of strains caused a loss of glycosylation sites at 24-NST. In conclusion, the strains that caused the epidemic of H3N2 influenza in Guangzhou in 2022 were not evolved or transmitted from the local strains in 2019 during the COVID-19 pandemic.

Objective:To establish a rapid pipeline for whole genome sequencing of Chikungunya virus (CHIKV) by combining imbricated multiplex-PCR amplification and Illumina high-throughput sequencing platform.Methods:The primary reference sequences of CHIKV were downloaded from the National Center for Biotechnology Information (NCBI) database, covering all genotypes of CHIKV. After multiple alignments using the Mafft software and phylogenetic analysis, the 20 CHIKV references were selected for primer design. The Primal Scheme tool and Geneious Prime software were used to design, evaluate and optimize the primer panel. Finally, seven CHIKV-positive samples were involved in the validation of the primer panel.Results:All the amplicons of the designed panel were generated successfully. The consensuses generated from the mapping results could cover 100.00% of the coding region of the CHIKV genome when the Ct-value of the sample was less than 33, as the percentage would decrease to 99.38% when the Ct-value reached 35. The mapping percentage could be increased by 5.70%-25.43% when using the stepwise correction mapping strategy.Conclusion:The multiplex-PCR amplification method for CHIKV whole genome sequencing is relatively simple and convenient, which only requires two tubes of PCR amplification and performs well on CHIKV-positive clinical samples with different concentration levels of virus.

At present, public health education in colleges and universities has many problems, such as insufficient education and practice for infectious diseases, serious shortage of public health talents, insufficient interdisciplinary integration of public health disciplines, lack of a holistic view of public health, and insufficient flexibility and autonomy of curriculum design in colleges and universities. These problems were closely related to the cultivation of practical ability of public health talents in colleges and universities. The new era puts forward high requirements for the construction of high-level schools of public health and the training of high-level public health talents, presenting both opportunities and challenges. The School of Public Health, Sun Yat-sen University proposed the idea of "combined peacetime and wartime training" to cultivate high-level public health talents who can solve practical problems, and jointly established a demonstration base for high-level public health talents training with Guangzhou Center for Disease Control and Prevention (CDC). The core content is “one class, one team, one hospital and one center”. The experimental class of "medical, prevention and management" talents, the Sun Yat-sen University-Guangzhou Volunteer Service Team for Epidemiological Investigation, the Graduate School of Guangzhou CDC, and the Joint Research Center of for Disease Surveillance and Early Warning and Risk Assessment of Sun Yat-sen University-Guangzhou CDC has been established. Virtual simulation experiments and simulation exercises have been conducted. It is an innovated training for high-level public health talents. The linkage between universities and CDCs to promote the development of public health disciplines can provide reference for public health personnel training in universities to cultivate high-level public health talents with the ability to solve practical problems.

Objective:To understand the incidence and risk factors of high-risk drowning behaviors among primary and middle school students in Shufu county, Kashgar area, Xinjiang Uygur Autonomous Region, and provide a theoretical basis for the development of drowning prevention policies and intervention measures.Methods:Cluster random sampling method was adopted in Bulakesu and Uppal of Shufu county. A total of 28 primaries and 2 middle schools were selected, and questionnaires surveyed all the students in grades 1-8.Results:A total of 14 543 questionnaires were sent out. 23.9% of primary and secondary school students had experienced high-risk drowning behavior in the past 12 months. Higher swimming level, introversion, intense curiosity, poor relationship with classmates, poor relationship with family, and open water near the school and open water near home were the risk factors of high-risk drowning behaviors.Conclusions:More attention should be paid to the psychology and high-risk behaviors of primary and middle school students, and the education of drowning knowledge and skills should be strengthened. Meanwhile, schools and communities should pay attention to the management and intervention of open water.