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The objective of the study is to analyze the implementation effect of the Live Attenuated Varicella Vaccine (VarV) Vaccination Program for eligible children in Bao’an District, Shenzhen, and evaluate the vaccine effectiveness. Children’s vaccination data was obtained from the Shenzhen Immunization Planning Information Management System, while varicella case data came from the China Disease Prevention and Control Information System. The Joinpoint regression method examined vaccination rate trends, and a retrospective cohort study assessed vaccine effectiveness. After program implementation, VarV vaccination rates significantly increased, surpassing provincial and national averages. Overall incidence declined 54.6% across age groups, with the largest reductions among 7- and 6-year-olds. One year post-vaccination, single-dose vaccine effectiveness was 91.1% (95% CI: 79.2% to 96.2%). However, two doses remained 91.4% effective(95% CI: 89.1% to 93.2%) after 7 years. Overall, Shenzhen’s VarV program achieved positive results. For children under six, routine immunization with two doses of VarV should be strengthened. Furthermore, we recommend that physicians conduct thorough inquiries to ascertain patients’ vaccination history and previous varicella infections. This will enable doctors to provide tailored vaccination recommendations based on comprehensive, practical evaluations.

China has been continuously improving its monitoring methods and strategies to address key infectious diseases (KIDs). After the severe acute respiratory syndrome epidemic in 2003, China established a comprehensive reporting system for infectious diseases (IDs) and public health emergencies. The relatively lagging warning thresholds, limited warning information, and outdated warning technology are insufficient to meet the needs of comprehensive monitoring for modern KIDs. Strengthening early monitoring and warning capabilities to enhance the public health system has become a top priority, with increasing demand for early warning thresholds, information, and techniques, thanks to constant innovation and development in molecular biology, bioinformatics, artificial intelligence, and other identification and analysis technologies. A panel of 31 experts has recommended a fourth-generation comprehensive surveillance system targeting KIDs (41 notifiable diseases and emerging IDs). The aim of this surveillance system is to systematically monitor the epidemiology and causal pathogens of KIDs in hosts such as humans, animals, and vectors, along with associated environmental pathogens. By integrating factors influencing epidemic spread and risk assessment, the surveillance system can serve to detect, predict, and provide early warnings for the occurrence, development, variation, and spread of known or novel KIDs. Moreover, we recommend comprehensive ID monitoring based on the fourth-generation surveillance system, along with a data-integrated monitoring and early warning platform and a consortium pathogen detection technology system. This series of considerations is based on systematic and comprehensive monitoring across multiple sectors, dimensions, factors, and pathogens that is supported by data integration and connectivity. This expert consensus will provides an opportunity for collaboration in various fields and relies on interdisciplinary application to enhance comprehensive monitoring, prediction, and early warning capabilities for the next generation of ID surveillance. This expert consensus will serve as a reference for ID prevention and control as well as other related activities.

In June 2023, the 2022 global mpox (monkeypox) outbreak began to affect Guangdong Province, one of the first regions in mainland China to report mpox cases. By July 10, 2023, 93 mpox cases had been reported in Guangdong Province. This study describes the epidemiological characteristics of these patients by collecting and analyzing data on demographics, sexual behavior, medical history, travel history, clinical symptoms, and diagnostic pathways and processes. The 93 mpox cases were all men aged 20-48 years, 95.70 % were men who have sex with men (MSM), and 48.39 % were HIV-positive. A few cases were married (to women) or living with children. The rash was present in almost all cases (98.91 %), with the most common sites being the genital and perianal areas (70.33 %). Intimate sexual contact was suspected to be the main route of infection, with a median incubation period of 8.5 days (IQR 5.0–11.8). The number of cases increased rapidly, and most patients had no history of international travel, suggesting sustained community transmission within the MSM population in Guangdong Province. In addition, 93.55 % of cases were detected by medical institutions, and more than half of these patients had two or more hospital visits before being diagnosed as an mpox case, indicating that clinicians need further training to increase their sensitivity to mpox. Targeted interventions should prioritize MSM while remaining vigilant for transmission to other populations, such as women and children.

This paper comprehensively analyses the first-ever monkeypox outbreak in Shenzhen, China, encompassing clinical symptomatology, therapeutic approaches, epidemiological research, and comprehensive laboratory tests, aiming to establish a robust reference for future monkeypox mitigation and management strategies. The investigation involved a thorough investigation of all identified positive cases, including extensive molecular analysis by nucleic acid detection and whole-genome sequencing of the monkeypox virus. Contact tracing and containment of the infected individuals were also undertaken. Three distinct monkeypox cases were identified in this unique outbreak, exhibiting mild and atypical clinical manifestations, primarily fever and rash. All cases were associated with a single transmission chain, primarily facilitated through close contact and homosexual behavior, indicative of a high-risk factor for monkeypox transmission.

We analyzed variations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome during a flight-related cluster outbreak of coronavirus disease 2019 (COVID-19) in Shenzhen, China, to explore the characteristics of SARS-CoV-2 transmission and intra-host single nucleotide variations (iSNVs) in a confined space. Thirty-three patients with COVID-19 were sampled, and 14 were resampled 3–31 days later. All 47 nasopharyngeal swabs were deep-sequenced. iSNVs and similarities in the consensus genome sequence were analyzed. Three SARS-CoV-2 variants of concern, Delta (n = 31), Beta (n = 1), and C.1.2 (n = 1), were detected among the 33 patients. The viral genome sequences from 30 Delta-positive patients had similar SNVs; 14 of these patients provided two successive samples. Overall, the 47 sequenced genomes contained 164 iSNVs. Of the 14 paired (successive) samples, the second samples (T2) contained more iSNVs (median: 3; 95% confidence interval [95% CI]: 2.77–10.22) than did the first samples (T1; median: 2; 95% CI: 1.63–3.74; Wilcoxon test, P = 0.021). 38 iSNVs were detected in T1 samples, and only seven were also detectable in T2 samples. Notably, T2 samples from two of the 14 paired samples had additional mutations than the T1 samples. The iSNVs of the SARS-CoV-2 genome exhibited rapid dynamic changes during a flight-related cluster outbreak event. Intra-host diversity increased gradually with time, and new site mutations occurred in vivo without a population transmission bottleneck. Therefore, we could not determine the generational relationship from the mutation site changes alone.

We identified an individual who was coinfected with two SARS-CoV-2 variants of concern, the Beta and Delta variants. The ratio of the relative abundance between the two variants was maintained at 1:9 (Beta:Delta) in 14 days. Furthermore, possible evidence of recombinations in the Orf1ab and Spike genes was found.

Objective To analyse the epidemiological characteristics of family clusters of COVID-19 and the three stages of the comprehensive non-pharmaceutical interventions and measures implemented in Shenzhen.Methods The epidemic curve of COVID-19 was drawn and the impact of the comprehensive non-pharmaceutical interventions and measures was analysed by the different periods of the epidemic.Results A total of 427 cases (417 confirmed cases and 10 asymptomatic infectious cases) were reported in Shenzhen, of which 259 (60.7%) were clustered cases. 97 cluster events were drawn and most cluster events (97.3%) occurred in families. There were three stages of the COVID-19 epidemic in Shenzhen. The epidemic increased rapidly, but the peak lasted for a short time, while the decline in incidence was rapid and large.Conclusions Family clusters were the main feature of the COVID-19 outbreak in Shenzhen in 2020, and the Shenzhen government rolled out a quick response to the epidemic. Non-pharmaceutical interventions and measures were proven to have effectively contained community transmission, limit the transmission to aggregation and reduce the scale of transmission within a household.

OBJECTIVES:Varicella (chickenpox) is a highly transmissible childhood disease. Between 2010 and 2015, it displayed two epidemic waves annually among school populations in Shenzhen, China. However, their transmission dynamics remain unclear and there is no school-based vaccination programme in Shenzhen to-date. In this study, we developed a mathematical model to compare a school-based vaccination intervention scenario with a baseline (i.e. no intervention) scenario. METHODS:Data on varicella reported cases were downloaded from the Infectious Disease Reporting Information Management System. We obtained the population size, age structure of children aged 15 or under, the class and school distribution from Shenzhen Education Bureau. We developed an Agent-Based Susceptible-Exposed-Infectious-Recovered (ABM-SEIR) Model that considered within-class, class-to-class and out-of-school transmission modes. The intervention scenario was that school-wide vaccination intervention occurred when an outbreak threshold was reached within a school. We varied this threshold level from five to ten cases. We compared the reduction of disease outbreak size and estimated the key epidemiological parameters under the intervention strategy. RESULTS:Our ABM-SEIR model provided a good model fit to the two annual varicella epidemic waves from 2013 to 2015. The transmission dynamics displayed strong seasonality. Our results suggested that a school-based vaccination strategy could effectively prevent large outbreaks at different thresholds. CONCLUSIONS:There was a considerable increase in reported varicella cases from 2013 to 2015 in Shenzhen. Our modelling study provided important theoretical support for disease control decision making during school outbreaks and the development of a school-based vaccination programme.