Objective: To analyze the epidemiological characteristics of varicella among nursery children in Shenzhen from 2015 to 2024, and to evaluate the impact of optimizing varicella vaccine (VarV) immunization strategies on varicella incidence. Methods: Varicella incidence data for nursery children in Shenzhen from 2015 to 2024 were obtained from the China Disease Prevention and Control Information System. The study period was divided into three phases:one dose self pay VarV (January 2015 to October 2017), two dose self pay VarV (November 2017 to October 2019), and two dose free VarV (November 2019 to December 2024). Interrupted time series (ITS) analysis was conducted to assess changes in the level and trend of varicella incidence associated with each phase of policy implementation. Results: A total of 27 517 varicella cases was reported among nursery children from 2015 to 2024, with an average annual incidence of 514.01/100 000. During the same period, 136 clustered outbreaks were reported in nursery institutions, involving a cumulative total of 1 091 cases. ITS analysis showed that during the self pay 1 dose stage, the varicella incidence among nursery children showed an upward trend, with an average monthly increase of 2.58/100 000 (95% CI =2.21/ 100 000 -2.95/100 000, P <0.01). After the implementation of the self pay 2 dose strategy, the incidence decreased, with a change in incidence of -26.12/100 000 (95% CI =-37.30/100 000 to -14.94/100 000) and a change in slope of -2.65/100 000 (95% CI = -3.38/100 000 to -1.93/100 000)(all P <0.01). After the implementation of the free 2 dose strategy, the incidence decreased further, with a change in incidence of -40.03/100 000 (95% CI =-50.39/100 000 to -29.66/100 000, P <0.01) and a change in slope of -0.56/100 000 (95% CI =-1.20/100 000-0.08/100 000, P =0.09). Conclusion The gradual optimization of the VarV vaccination strategy in Shenzhen from self pay 1 dose to free 2 dose has significantly reduced the varicella incidence among nursery children, demonstrating good short term control and long term intervention effectiveness.

Objective To examine the association between epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) and meteorological factors in Shenzhen City during the period from 2012 to 2019. Methods Average atmospheric pressure, average air temperature, average relative humidity, precipitation, wind speed, and sunshine duration were captured from Meteorological Bureau of Shenzhen City each month from 2012 to 2019. The average monthly rodent densities in Shenzhen City from 2012 to 2019 were acquired from the Vector Surveillance Management System of Guangdong Provincial Center for Disease Control and Prevention, and the monthly HFRS incidence was retrieved from Shenzhen Municipal Disease Surveillance System from 2012 to 2019. The correlation between meteorological factors and the monthly incidence of HFRS was examined us ing Spearman’s rank correlation in Shenzhen City, and the temporal trends in monthly HFRS incidence and the degrees of freedom for the rodent density were determined in Shenzhen City with a generalized additive model. The optimal lag time was identified using excess risk (ER) and its 95% confidence interval (CI), and univariate and multivariate models were fitted to evaluate the impact of meteorological factors on HFRS incidence in Shenzhen City. Results The median number of incident HFRS cases was 3.00 (interquartile range, 3.25) in Shenzhen City from 2012 to 2019, with an average air temperature of (23.44 ± 4.91) °C, average relative humidity of (76.05 ± 7.61)%, median precipitation of 4.10 (interquartile range, 6.83) mm, average wind speed of (1.97 ± 0.26) m/s, average sunshine duration of (5.17 ± 1.64) h, and median monthly rodent density of 1.74% (interquartile range, 2.52%). Spearman’s rank correlation analysis showed that the average air temperature positively correlated with average relative humidity (r_s = 0.420, P < 0.05), precipitation (r_s = 0.658, P < 0.05) and sunshine duration (r_s = 0.633, P < 0.05), and the atmospheric pressure negatively correlated with average air temperature (r_s = −0.925, P < 0.05), relative humidity (r_s = −0.614, P < 0.05), precipitation (r_s = −0.789, P < 0.05) and sunshine duration (r_s = −0.437, P < 0.05), while the average relative humidity correlated positively with precipitation (r_s = 0.724, P < 0.05) and negatively with sunshine duration (r_s = −0.218, P < 0.05). Univariate modeling analysis showed that the ERs and their 95% CI were 0.639% (0.540%, 0.737%) for average atmospheric pressure, −7.157% (−8.113%, −6.190%) for average air temperature, −3.603% (−4.219%, −2.985%) for average relative humidity, −5.889% (−7.085%, −4.669%) forprecipitation,21.881% (−5.149%, 56.612%) for average wind speed, and −13.877% (−16.641%, −11.022%) for sunshine duation (all P values < 0.05). Multivariate modeling analysis showed that in the ensemble model combining average atmospheric pressure and precipitation, the highest ER (6.686%) was caused by increased average atmospheric pressure, and the highest absolute ER values for average air temperature (6.615%), average relative humidity (3.107%) and precipitation (5.386%) were seen after adjustment only for sunshine duration (all P values < 0.05), while the highest absolute ER for sunshine duration (11.875%) was found after adjustment for precipitation (P < 0.05). Conclusions An increase in average air temperature, relative humidity, precipitation and sunshine duration resulted in a reduced incidence rate of HFRS in Shenzhen City from 2012 to 2019, and an increase in average atmospheric pressure increased the incidence of HFRS. Meteorological factors are important determinants affecting HFRS incidence in Shenzhen City.

Objective To investigate the epidemiological characteristics of dengue fever in Shenzhen City in 2024, so as to provide insights into formulation of the preventive and control measures for dengue fever. Methods The epidemiological data of dengue cases reported in Shenzhen City in 2024 were extracted from the China Disease Prevention and Control Information System and field epidemiological survey data of dengue fever in Shenzhen City, and the temporal, regional and population distributions of dengue fever cases, source of acquire dengue virus infections, disease diagnosis and treatment and outbreaks were analyzed. The dengue virus nucleic acid was tested and the serotypes of dengue virus were characterized using real-time quantitative reverse transcription PCR (RT-qPCR) assay, and the dengue virus gene was sequenced using next-generation sequencing (NGS). In addition, the surveillance on the density of Aedes albopictus was performed using Breteau index (BI) and mosquito oviposition index (MOI). Results A total of 1 735 dengue fever cases were reported in Shenzhen City in 2024, including 952 local cases and 783 imported cases. Most imported dengue fever cases acquired infections from eight cities of Foshan, Guangzhou, Zhongshan, Jiangmen, Dongguan, Zhaoqing, Huizhou, and Zhuhai in the Pearl River Delta region (664 cases, 84.8% of total imported cases) into Baoan, Longgang, and Nanshan districts. The epidemic exhibited an early onset and rapid progression, peaking during the period between September and November (1 632 cases, 94.1% of total cases), and dengue fever cases were distributed across 73 subdistricts in 10 districts, with most cases reported in densely populated central and western regions. The dengue fever cases had a male-to-female ratio of 1.9∶1.0, and a median age of 37 (21) years, with a higher median age among local cases than among imported cases [40 (20) years vs. 33(15) years; Z = -10.30, P < 0.05]. Housework, unemployment, workers, and business service were predominant occupations (1 405 cases, 81.0% of total cases), and there was a significant difference in the constituent ratio of occupations between local and imported cases (χ² = 92.30, P < 0.05). Among the 1 735 dengue fever cases, the median duration from onset to definitive diagnosis was 3.3 (2.9) days, and 1 686 cases (97.2%) were identified in healthcare facilities, with a low rate of hospitalization and isolation seen in 1 701 inpatients with available epidemiological data (485 cases, 28.5% of total inpatients). A total of 29 outbreaks of dengue fever occurred in Shenzhen City across 2024, which primarily in construction sites (27 outbreaks, 93.1% of total). Dengue virus type I was the dominant serotype causing dengue fever in Shenzhen City in 2024. Sequencing showed that the genomes of dengue virus from multiple dengue fever cases in Shenzhen City shared a high sequence homology with those from cities neighboring Shenzhen City, and there might be intra-city transmission of dengue virus among multiple construction sites in Shenzhen City. The Aedes albopictus density was significantly higher in Shenzhen City in 2024 than in 2023, peaking from May to September. The annual MOI values ranged from 0.9 to 14.0, and the BI values ranged from 0.6 to 6.0. Conclusions The overall epidemic of dengue fever was severe in Shenzhen City in 2024, which was greatly affected by case importation from neighboring cities, construction sites-centered local transmission, and the effectives of routine mosquito vector control was not satisfactory. Integrated dengue fever control measures should be implemented, focusing on regional joint prevention and control mechanisms, capacity building for mosquito vector control, addressing challenges in epidemic containment at construction sites, and strengthening case detection and management systems.

Objective:To assess the cost-effectiveness of influenza vaccination among people aged 60 years and older in Shenzhen.Methods:A Markov state transition model was constructed to evaluate the cost-effectiveness of annual influenza vaccination for preventing influenza infection compared with no vaccination among the elderly from the social perspective. Allowing seasonal variation of influenza activity, the model followed a five-year cohort using weekly cycles. We employed once the Chinese gross domestic product (GDP) per capita in 2019 (70 892 yuan) as the willingness-to-pay (WTP) threshold and calculated the net monetary benefit (NMB) with costs and quality-adjusted life-years (QALYs) discounted at 5% annually. The impact of parameter uncertainty on the results was examined using one-way and probabilistic sensitivity analyses (PSA).Results:The base case amounted to approximately 35 yuan of cost-saving and a net gain of 0.007 QALYs. Correspondingly, the NMB was 529 yuan per vaccinated person. One-way sensitivity analyses showed that the NMB was relatively sensitive to changes in the attack rate of influenza and vaccine effectiveness. Based on the results of PSA with 1 000 Monte Carlo simulations, influenza vaccination had a probability of being cost-effective in 100% of the repetitions.Conclusions:The present study provides evidence that influenza vaccination is a cost-saving disease prevention strategy for people aged 60 years and older in Shenzhen.

Objective: To investigate the protective effect of intraperitoneal transplantation of human liver-derived stem cells at different times against concanavalin A (ConA)-induced acute liver injury in mice. Methods: A total of 88 male C57BL/6 mice were randomly divided into normal control group (group C), ConA model group (group M), and human liver-derived stem cells (HYX1)+ConA group (group E); according to the interval between phosphate buffer/HYX1 injection and ConA injection, Groups M and E were further divided into 3-hour groups (M1 and E1 groups), 6-hour groups (M2 and E2 groups), 12-hour groups (M3 and E3 groups), 24-hour groups (M4 and E4 groups), and 48-hour groups (M5 and E5 groups). The levels of alanine aminotransferase (ALT), aspartate transaminase (AST), and total bilirubin (TBil) in peripheral blood were measured, liver tissue sections were used to observe pathological changes, and the Ishak score for liver inflammation was determined. The independent samples t-test was used for comparison between groups, and P < 0.05 was considered statistically significant. Results: The levels of ALT, AST, and TBil in group C were (36.25±1.16) U/L, (120.20±5.77) U/L, and (2.20±0.23) μmol/L, respectively; the levels of ALT, AST, and TBil and Ishak score were (8 721.23±837.39) U/L, (8 110.31±290.10) U/L, (8.41±0.10) μmol/L, and (13.32±1.30), respectively, in group M1, (8 334.31±666.50) U/L, (7 560.20±760.34) U/L, (10.40±0.80) μmol/L, and (12.67±0.81), respectively, in group M2, (8 960.75±551.93) U/L, (8 535.62±675.14) U/L, (10.95±1.43) μmol/L, and (14.57±0.65), respectively, in group M3, (8 618.57±886.40) U/L, (11 440.54 ± 1 327.86) U/L, (13.30±1.86) μmol/L, and (13.21±1.06), respectively, in group M4, and (10 170.13±1 112.37) U/L, (11 470.56±1 108.40) U/L, (12.75±1.55) μmol/L, and (15.07±1.58), respectively, in group M5. The levels of ALT, AST, and TBil and Ishak score were (1 016.35±163.47) U/L, (952.30±103.91) U/L, (7.77±0.62) μmol/L, and (3.50±0.21), respectively, in group E1, (42.10±6.20) U/L, (126.72±13.33) U/L, (3.41±0.53) μmol/L, and (2.01±0.40), respectively, in group E2, (44.21±4.30) U/L, (216.71±35.88) U/L, (3.47±0.44) μmol/L, and (2.13±0.25), respectively, in group E3, (2 909.69±212.14) U/L, (2 988.43±333.70) U/L, (7.03±0.93) μmol/L, and (4.70±0.50), respectively, in group E4, and (7 874.26±799.60) U/L, (10 940.54±947.35) U/L, (10.53±1.09) μmol/L, and (8.60±0.83), respectively, in group E5. Groups M1-M5 had significantly higher levels of ALT, AST, and TBil than group C (all P < 0.01), and groups M1-M4 had significantly higher levels of AST and ALT than groups E1-E4 (all P < 0.01), while there were no significant differences in the levels of AST and ALT between groups M5 and E5 (both P > 0.05). The pathological sections of liver tissue showed that compared with group M, group E had significant reductions in the degree of necrosis and Ishak score (both P < 0.05). Conclusion Intraperitoneal transplantation of human liver-derived stem cells has a protective effect against ConA-induced acute liver injury in mice, and the injection at 6 and 12 hours in advance has the best protective effect.

Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Cell Line, Tumor ; drug effects ; Humans ; Leukemia ; pathology ; Oxides ; pharmacology

OBJECTIVETo study the blocking effect of CXCR4 inhibitor AMD3100 on the adhesion of leukemia cells to osteoblast niche, and the reversal of multidrug resistance in leukemia cells.

METHODSMesenchymal stem cells (MSCs) from leukemia patients were planted on the bio-derived bone scaffolds and then induced into osteoblasts to establish the bio-osteoblast niche. The levels of SDF-1were tested with ELISA. The leukemia cell line MV4-11 cells with FLT3-ITD mutation were inoculated into the bio-osteoblast niche to build a three-dimensional co- culture system. The expression level of CXCR4, adhesion and apoptosis rates of leukemia cells were observed by flow cytometry after incubation with AMD3100 and Ara-C for 24 h and 48 h.

RESULTS(1)The supernatant levels of SDF-1 in cultured osteoblast were (304 ± 18), (410 ± 28) and (396 ± 16) pg/ml on 7 th, 14 th and 21 th day, respectively. It reached the highest on 14 th day. The expression level of CXCR4 in cultured MV4-11 cells was (72 ± 16)%. (2)Adhesion rate of MV4-11 cells to osteoblast niche was (40.1 ± 8.1)% after AMD3100 treatment for 24 h, while that of control group was (65.6 ± 12.1)% (P<0.05). (3)The apoptosis rate of MV4-11 cells incubated with AMD3100 for 24 h was (5.6 ± 0.8)%, while that of control group was (2.5 ± 0.5)%. The apoptosis rates of AMD3100-induced MV4-11 cells were (10.0 ± 2.4)%, (17.8 ± 2.3)% and (25.1 ± 2.4)% after treatment with Ara-C at 0.02, 0.20, 2.00 mg/ml respectively and they were (6.7 ± 1.0)%, (10.3 ± 1.5)%, (16.2 ± 3.1)% respectively in AMD3100-noninduced control group, the difference was significant (P<0.05).

CONCLUSIONAMD3100 can block the interaction between osteoblasts niches and leukemia cells, and play an important role in the reversal of multidrug resistance in leukemia cells.

Apoptosis ; Cell Adhesion ; Cell Line, Tumor ; Chemokine CXCL12 ; Coculture Techniques ; Cytarabine ; Drug Resistance ; Flow Cytometry ; Heterocyclic Compounds ; Humans ; Leukemia ; Mesenchymal Stromal Cells ; Osteoblasts ; Receptors, CXCR4 ; Signal Transduction

OBJECTIVETo establish the single genome amplification (SGA) method and analyze the quasispecies in HIV-infected patients.

METHODSAll 6 sample RNA acquired in 2010 in Shenzhen and genetic sequenced as overlap peaks were extracted and diluted to a single copy, nest-PCR after one step RT-PCR was employed to amplify HIV-1 genome, and then PCR products was purified and sequenced. Mega 4.02 software was used to analyze the genetic distance among HIV-1 quasispecies, and phylogenetic tree was constructed.

RESULTSOur data showed that viral sequences derived from different patients were grouped into different clusters. Subcluster was also observed in several clusters, indicating these existed competition and preferential replication of certain viral strains. The genetic distance within one cluster of 6 samples were between 0.008 and 0.06, it was likely to associate with the duration since infection and viral load.

CONCLUSIONSGA is a useful approach to gain information on quasispecies, the genetic distance within one cluster may help to determine the infection time and immune escaping. The analysis of related affecting factors need more samples.

Base Sequence ; Genome, Viral ; HIV Infections ; HIV-1 ; Humans ; Phylogeny ; Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Viral Load

Objective To establish the single genome amplification ( SGA) method and analyze the quasispecies in HIV-infected patients.Methods All 6 sample RNA acquired in 2010 in Shenzhen and genetic sequenced as overlap peaks were extracted and diluted to a single copy , nest-PCR after one step RT-PCR was employed to amplify HIV-1 genome , and then PCR products was purified and sequenced.Mega 4.02 software was used to analyze the genetic distance among HIV-1 quasispecies , and phylogenetic tree was constructed.Results Our data showed that viral sequences derived from different patients were grouped into different clusters.Subcluster was also observed in several clusters , indicating these existed competition and preferential replication of certain viral strains.The genetic distance within one cluster of 6 samples were between 0.008 and 0.06, it was likely to associate with the duration since infection and viral load.Conclusion SGA is a useful approach to gain information on quasispecies , the genetic distance within one cluster may help to determine the infection time and immune escaping.The analysis of related affecting factors need more samples.

Objective To establish the single genome amplification ( SGA) method and analyze the quasispecies in HIV-infected patients.Methods All 6 sample RNA acquired in 2010 in Shenzhen and genetic sequenced as overlap peaks were extracted and diluted to a single copy , nest-PCR after one step RT-PCR was employed to amplify HIV-1 genome , and then PCR products was purified and sequenced.Mega 4.02 software was used to analyze the genetic distance among HIV-1 quasispecies , and phylogenetic tree was constructed.Results Our data showed that viral sequences derived from different patients were grouped into different clusters.Subcluster was also observed in several clusters , indicating these existed competition and preferential replication of certain viral strains.The genetic distance within one cluster of 6 samples were between 0.008 and 0.06, it was likely to associate with the duration since infection and viral load.Conclusion SGA is a useful approach to gain information on quasispecies , the genetic distance within one cluster may help to determine the infection time and immune escaping.The analysis of related affecting factors need more samples.