Development of a High-throughput Sequencing Platform for Detection of Viral Encephalitis Pathogens Based on Amplicon Sequencing

Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing.Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing.Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing.Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.

Willingness to pay for colorectal cancer screening in Guangzhou

AIM To measure the willingness to pay for colorectal cancer screening in Guangzhou, and to identify those factors associated with it. METHODS A face-to-face questionnaire survey for pre-screening population from free and non-free colonoscopy districts was used to collect information on demographic characteristics, health behaviours, the intention of the cancer screenings and willingness to pay for colorectal cancer screening. A total of 1243 participants who took part in the pre-screening for colorectal cancer in Guangzhou were collected in the study. Categorical data were compared using the χ~2 test to analyse significant differences. Non-conditional logistic regression and multi-class logistic regression were also performed for multivariate analysis and to estimate the odds ratios.RESULTS The percentage of participants willing to pay for colorectal cancer screening was 91.7%. "Unnecessary" was the dominant reason that participants gave for their unwillingness, accounting for 63.1%. Of those who were willing to pay, 29.2%, 20.7%, 14.8%, 13.0% and 22.4% of participants were willing to pay less than $100, $100-$199, $200-299, $300-$399 and more than $400, respectively. Non-logistic regression analysis showed that respondents who were male, had a high level of education, were from the family with more children/older to raise, and accepted colorectal cancer screening were willing to pay for this screening. Multi-class logistic regression analysis showed that respondents with higher annual household income per capita, from government and private enterprises, government agency/institution and peasants, and less family medical expenditure were willing to pay more.CONCLUSION Willingness to pay for colorectal cancer screening in Guangzhou is high, but the amount of willing to pay is not much.

Magnitude and direction of temperature variability affect hospitalization for myocardial infarction and stroke:population-based evidence from Guangzhou,China

Relationships between nonoptimal temperatures and cardiovascular disease(CVD)mortality have been well documented.However,evidence of the association between temperature variability(TV)and CVD morbidity is limited.This study aimed to quantify the risk and burden of CVD-related hospitalization associated with the magnitude and direction of TV.Data on meteorology and population-based hospitalizations for myocardial infarction(MI)and stroke were collected in Guangzhou,China,from 2013 to 2017.Hourly temperature variability(HTV)was measured as the standard deviation of hourly temperature records over specific exposure days.The direction(upward or downward)of HTV was defined as the average daily mean temperature change relative to that of the previous day during the exposure period.Quasi-Poisson regression was applied to assess the impact of HTV after adjusting for the daily mean temperature,and the hospitalization fractions attributable to HTV were calculated.A 1°C-increase in HTV was significantly associated with a 2.24%and 1.72%increase in hospitalizations for MI and hemorrhagic stroke(HS)at lag 0–1 d,respectively,and a 1.55%increase in hospitalizations for ischemic stroke(IS)at lag 0–3 d.During the study period,5.99%,4.64%,and 4.53%of MI,HS,and IS hospitalizations,respectively,were attributable to HTV.The upward TV exerts acute effects on CVD hospital admissions,whereas the impact of downward TV generally lags.These findings highlight the importance of the magnitude and direction of temperature fluctuations,in addition to the mean level,in assessing the adverse health impacts of temperature variations.

Incidence trends and age distribution of colorectal cancer by subsite in Guangzhou,2000-2011

Introduction:Colorectal cancer(CRC) is the third most common cancer in China.The incidence of CRC has been increasing in recent years.The aim of this study was to explore the incidence trends and the age distribution of CRC by subsite in Guangzhou between 2000 and 2011.Methods:A total of 22,432 incident cases of CRC between 2000 and 2011 from Guangzhou Cancer Registry were identified.Crude incidence and age-standardized rates(ASRs),using the Segi’s world standard population,were calculated for CRC and CRC subsites.The incidence trend was analyzed and the annual percentage change(APC) in incidence was calculated by using JoinPoint software.Results:The crude incidence increased significantly from 23.4/10~5 in 2000 to 37.4/10~5 in 2011 for males and from20.9/10~5 to 30.5/10~5 for females.The ASRs of CRC incidence stabilized during the period of 2000-2011 for both males and females.The ages at the onset of CRC for both males and females during 2010-2011 were significantly higher compared with those during 2000-2002(males:f = 1.95,P = 0.05;females:f = 6.03,P < 0.01).For males aged50-64 years,the CRC incidence increased by 8.50%annually(P = 0.04) during 2000-2004 and by 1.68%annually(P = 0.03) during 2005-2011.For females aged 65 years and older,the CRC incidence increased by 5.77%annually(P = 0.03) during 2000-2004.There were no significant changes for the CRC incidences in males aged 49 and younger and 65 years and older and females aged 64 years and younger during 2000-2004,or for those in all females as well as males aged 49 years and younger and 65 years and older during 2005-2011.The percentage of colon cancer in all CRCs increased significantly for both males and females between the periods of 2000-2002 and 2010-2011.The ASRs of descending colon and sigmoid colon cancer incidences increased significantly for females during 2005-2011(APC,5.51%and 1.08%,respectively,both P < 0.05).Conclusions:The crude incidence of CRC increased significantly between 2000 and 2011 because of the aging,whereas the ASRs kept stable.The percentage of colon cancer in all CRCs increased significantly.Further surveillance,research,and intervention are needed to identify the causes of these changes and to reduce the incidence and mortality of CRC.

Impact of Heat Wave in 2005 on Mortality in Guangzhou, China

Objective To assess the impact of the heat wave in 2005 on mortality among the residents in Guangzhou and to identify susceptible subpopulations in Guangzhou, China. Methods The data of daily number of deaths and meteorological measures from 2003 to 2006 in Guangzhou were used in this study. Heat wave was defined as 〉7 consecutive days with daily maximum temperature above 35.0 ~C and daily mean temperature above the 97th percentile during the study period. The excess deaths and rate ratio （RR） of mortality in the case period compared with the reference period in the same summer were calculated. Results During the study period, only one heat wave in 2005 was identified and the total number of excess deaths was 145 with an average of 12 deaths per day. The effect of the heat wave on non-accidental mortality （RR=l.23, 95% CI： 1.11-1.37） was found with statistically significant difference. Also, greater effects were observed for cardiovascular mortality （RR=l.34, 95% Cl： 1.13-1.59） and respiratory mortality （RR=I.31, 95% CI： 1.02-1.69）. Females, the elderly and people with lower socioeconomic status were at significantly higher risk of heat wave-associated mortality. Conclusion The 2005 heat wave had a substantial impact on mortality among the residents in Guangzhou, particularly among some susceptible subpopulations. The findings from the present study may provide scientific evidences to develop relevant public health policies and prevention measures aimed at reduction of preventable mortality from heat waves.

Dengue Fever Epidemiological Status and Relationship with Meteorological Variables in Guangzhou, Southern China, 2007-2012

Ecological methodology plus negative binomial regression were used to identify dengue fever （DF） epidemiological status and its relationship with meteorological variables. From 2007 to 2012, annual incidence rate of DF in Guangzhou was 0.33, 0.11, 0.15, 0.64, 0.45, and 1.34 （per 100 000） respectively, showing an increasing trend. Each 1℃ rise of temperature corresponded to an increase of 10.23% （95% CI 7.68% to 12.83%） in the monthly number of DF cases, whereas l hPa rise of atmospheric pressure corresponded to a decrease in the number of cases by 5.14% （95% CI： 7.10%-3.14%）. Likewise, each one meter per second rise in wind velocity led to an increase by 43.80% or 107.53%, and one percent rise of relative humidity led to an increase by 2.04% or 2.19%.

The Impacts of Mosquito Density and Meteorological Factors on Dengue Fever Epidemics in Guangzhou, China, 2006-2014: a Time-series Analysis

Objective To explore the associations between the monthly number of dengue fever（DF） cases and possible risk factors in Guangzhou, a subtropical city of China. Methods The monthly number of DF cases, Breteau Index （BI）, and meteorological measures during 2006-2014 recorded in Guangzhou, China, were assessed. A negative binomial regression model was used to evaluate the relationships between BI, meteorological factors, and the monthly number of DF cases. Results A total of 39,697 DF cases were detected in Guangzhou during the study period. DF incidence presented an obvious seasonal pattern, with most cases occurring from June to November. The current month＇s BI, average temperature （Tare）, previous month＇s minimum temperature （Train）, and Tare were positively associated with DF incidence. A threshold of 18.25℃ was found in the relationship between the current month＇s Tmin and DF incidence. Conclusion Mosquito density, Tove, and Tmin play a critical role in DF transmission in Guangzhou. These findings could be useful in the development of a DF early warning system and assist in effective control and prevention strategies in the DF epidemic.

The Impact of Relative Humidity and Atmospheric Pressure on Mortality in Guangzhou, China

Objective Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impacts of atmospheric pressure and relative humidity on mortality in Guangzhou, China. Methods This study included 213,737 registered deaths during 2003-2011 in Guangzhou, China. A quasi-Poisson regression with a distributed lag non-linear model was used to assess the effects of atmospheric pressure/relative humidity. Results We found significant effect of low atmospheric pressure/relative humidity on mortality. There was a 1.79% （95% confidence interval： 0.38%-3.22%） increase in non-accidental mortality and a 2.27% （0.07%-4.51%） increase in cardiovascular mortality comparing the 5th and 25th percentile of atmospheric pressure. A 3.97% （0.67%-7.39%） increase in cardiovascular mortality was also observed comparing the 5th and 25th percentile of relative humidity. Women were more vulnerable to decrease in atmospheric pressure and relative humidity than men. Age and education attainment were also potential effect modifiers. Furthermore, low atmospheric pressure and relative humidity increased temperature-related mortality. Conclusion Both low atmospheric pressure and relative humidity are important risk factors of mortality. Our findings would be helpful to develop health risk assessment and climate policy interventions that would better protect vulnerable subgroups of the population.

Prevalence and modifiable risk factors of degenerative valvular heart disease among elderly population in southern China

Objective To investigate the prevalence and modifiable risk factors of degenerative valvular heart disease(DVHD)among elderly population in southern China.Methods A stratified multistage sampling method was used to recruit subjects.The contents of the survey included the questionnaire,laboratory examination,echocardiography,and other auxiliary examinations.The possible risk factors of DVHD were analyzed by logistic regression analysis.Results A total of 3538 subjects≥65 years of age were enrolled.One thousand three hundred and seven subjects(36.9%)were diagnosed with DVHD.Degenerative was the most common etiology of VHD.Prevalence of DVHD increased with advancing age.The prevalence of DVHD differed by living region(χ^(2)=45.594,P<0.001),educational level(χ^(2)=50.557,P<0.001),and occupation(χ^(2)=36.961,P<0.001).Risk factors associated with DVHD included age(two-fold increased risk for each 10-year increase in age),elevated level C-reactive protein(OR=1.346,95%CI:1.100-1.646),elevated level low density lipoprotein(OR=1.243,95%CI:1.064-1.451),coronary artery disease(OR=1.651,95%CI:1.085-2.513),smoking(OR=1.341,95%CI:1.132-1.589),and hypertension(OR=1.414,95%CI:1.221-1.638).Other significant risk factors included reduced or elevated level red blood cell(OR=1.347,95%CI:1.031-1.761;OR=1.599,95%CI:1.097-2.331;respectively),elevated level platelets(OR=1.891,95%CI:1.118-3.198),elevated level uric acid(OR=1.282,95%CI:1.112-1.479),and stroke(OR:1.738,95%CI=1.085-2.513).Conclusions The survey characterized the baseline conditions of DVHD cohort of elderly population in Guangzhou city.The established and emerging risk factors for DVHD may represent challenges and opportunities for therapy.

ON THE STUDY OF THE RELATIONSHIPS BETWEEN GUANGZHOU ATMOSPHERIC ENVIRONMENT FACTORS AND THE SARS EPIDEMIC

Based on SARS epidemic data and the corresponding atmospheric data, we used the timescale-partitioning technique, spectrum analysis and correlation analysis to investigate the impacts of the atmospheric environmental factors on the SARS epidemic. Results showed that there were close relations between environmental factors and SARS: The daily probable cases of SARS varied in 3-5 day cycles, much the same as the atmospheric elements did. The variations of the epidemics correlated remarkably with atmospheric elements. So conclusions can be drawn that weather changes have influences on the variations of daily SARS cases. In addition, statistical results showed that cold air activities aggravated the SARS epidemic.

Spatio-temporal analysis of the incidence of colorectal cancer in Guangzhou,2010-2014

Introduction: Colorectal cancer(CRC) is a common type of neoplasm. This study examined the spatio?temporal distribution of the CRC incidence in Guangzhou during 2010–2014.Methods: Colorectal cancer incidence data were obtained from the Guangzhou Cancer Registry System. Spatial autocorrelation analysis and a retrospective spatio?temporal scan were used to assess the spatio?temporal cluster distribution of CRC cases.Results: A total of 14,618 CRC cases were registered in Guangzhou during 2010–2014, with a crude incidence of 35.56/100,000 and an age?standardized rate of incidence by the world standard population(ASRIW) of 23.58/100,000. The crude incidence increased by 19.70% from 2010(32.88/100,000) to 2014(39.36/100,000) with an average annual percentage change(AAPC) of 4.33%. The AAPC of ASRIW was not statistically significant. The spatial autocorrelation analysis revealed a CRC incidence hot spot in central urban areas in Guangzhou City, which included 25 streets in southwestern Baiyun District, northwestern Haizhu District, and the border region between Liwan and Yuexiu Dis?tricts. Three high? and five low?incidence clusters were identified according to spatio?temporal scan of CRC incidence clusters. The high?incidence clusters were located in central urban areas including the border regions between Bai?yun, Haizhu, Liwan, and Yuexiu Districts.Conclusions: This study revealed the spatio?temporal cluster pattern of the incidence of CRC in Guangzhou. This information can inform allocation of health resources for CRC screening.

An Outbreak of Serogroup Y Meningococcal Meningitis in a Private Secondary Vocational School-Guangzhou City,Guangdong Province,China,2023

What is already known about this topic?The inclusion of meningococcal vaccines in the National Immunization Program(NIP)over several years has significantly reduced the incidence of meningococcal meningitis in China to historic lows.Worldwide,there has been a diversification of meningococcal serogroups,leading to a shift in dominant serogroups in China from serogroup A to serogroups C and B,accompanied by a rise in reports of serogroups Y and W.What is added by this report?An outbreak of serogroup Y Neisseria meningitidis(Nm)in a secondary vocational school involved a single confirmed severe case and 24 individuals with laboratory-confirmed Nm carriage.Epidemiological investigation revealed that the outbreak was localized to the classroom of the confirmed case.Prolonged close contact within a confined space was identified as a significant risk factor for Nm transmission.The genotype sequence identified was type 1655(ST-1655),which is categorized under clonal complex 23(CC-23)and bears resemblance to 8 previously confirmed cases of serogroup Y meningococcal meningitis within Guangdong Province.This suggests that serogroup Y infections continue to sporadically emerge and have become prevalent strains.What are the implications for public health practice?This outbreak underscores the critical need to enhance surveillance of meningococcal serogroups and population carrier,and advocate for vaccination with MenY-containing vaccines.

Nosocomial infection control in healthcare settings: Protection against emerging infectious diseases

The Middle East respiratory syndrome(MERS)outbreak in Korea in 2015 may be attributable to poor nosocomial infection control procedures implemented.Strict infection control measures were taken in the hospital where an imported case with MERS was treated in southern China and 53 health care workers were confirmed to be MERS-CoV negative.Infection control in healthcare settings,in which patients with emerging infectious diseases such as MERS,Ebola virus disease,and the severe acute respiratory syndrome(SARS)are diagnosed and treated,are often imperfect.When it comes to emerging or unknown infectious diseases,before the imported case was finally identified or community transmission was reported,cases have often occurred in clusters in healthcare settings.Nosocomial infection control measures should be further strengthened among the workers and inpatients in designated healthcare settings that accommodate suspected cases suffering from emerging or unknown infectious diseases.

Epidemiological Survey and Analysis on an Outbreak of Gastroenteritis due to Water Contamination

Objective To document the investigation and control of an outbreak of gastroenteritis in City G, South China, and provide a reference for preventing future outbreaks. Methods An ambispective cohort study was designed. Attack rate （AR） and relative risks （RR） were calculated to identify the causes of gastroenteritis. Investigations using questionnaires included personal interviews with patients and doctors, reviews of medical records, laboratory examinations of fecal specimens and continuous hygiene monitoring of water samples from the waterworks. Results Overall, 427/71534 （AR=5.97%o） cases were identified between October 31 and November 12 2010. Geographic distribution was highly localized, with 80% of cases occurring in the areas supplied by waterworks-A. Consumption of water provided solely by waterworks-A was found to be associated with illness （RR=8.20, 95 C1%：6.12-10.99） compared with that from waterworks-B. Microbiological analyses confirmed the presence of Norovirus in six of eight fecal samples from symptomatic patients, two water samples from waterworks-A and two sewage samples. After taking effective measures, the hygienic indices of waterworks-A met health criteria again on November 9 and no cases were reported 3 days later.Conclusion The outbreak reported here was caused by drinking tap water contaminated with sewage at the source. Early identification of possible contamination sources and awareness of changes that might negatively impact water quality are important preventive measures to protect public health.

Correlates of Condom-use Self-efficacy on the EPPM-based Integrated Model among Chinese College Students

Objective To explore the predictors of condom-use self-efficacy in Chinese college students according to the extended parallel process model （EPPM）-based integrated model. Methods A total of 3,082 college students were anonymously surveyed through self-administered questionnaires in Guangzhou and Harbin, China. A structural equation model was applied to assess the integrated model. Results Among the participants, 2,387 （46.7%） were male, 2,586 （53.3%） were female, and the average age was 18.6 years. The final integrated model was acceptable. Apart from the direct effect （r = 0.23）, perceived severity had two indirect effects on condom-use self-efficacy through the attitude to HIV education （r = 0.40） and intention to engage in premarital sex （r = -0.16）, respectively. However, the perceived susceptibility mediated through the intention to engage in premarital sex （intent-to-premarital-sex） had a poor indirect impact on condom-use self-efficacy （total effect was -0.06）. Furthermore, attitude toward HIV health education （r = 0.49） and intent-to-premarital-sex （r = -0.32） had a strong direct effect on condom-use self-efficacy. In addition, male students perceived higher susceptibility, stronger intent-to-premarital-sex, and lower condom-use self-efficacy than female students. Conclusion The integrated model may be used to assess the determinants of condom-use self-efficacy among Chinese college students. Future research should focus on raising the severity perception, HIV-risk-reduction motivation, and the premarital abstinence intention among college students. Furthermore, considering the gender differences observed in the present survey, single-sex HIV education is required in school-based HIV/sex intervention.

Estimation of cancer burden in Guangdong Province,China in 2009

Background:Surveying regional cancer incidence and mortality provides significant data that can assist in making health policy for local areas;however,the province- and region-based cancer burden in China is seldom reported.In this study,we estimated cancer incidence and mortality in Guangdong Province,China and presented basic information for making policies related to health resource allocation and disease control.Methods:A log-linear model was used to calculate the sex-,age-,and registry-specific ratios of incidence to mortality(l/M) based on cancer registry data from Guangzhou,Zhongshan,and Sihui between 2004 and 2008.The cancer incidences in 2009 were then estimated according to representative l/M ratios and the mortality records from eight death surveillance sites in Guangdong Province.The cancer incidences in each city were estimated by the corresponding sex- and age-specific incidences from cancer registries or death surveillance sites in each area.Finally,the total and region-based cancer incidences and mortalities for the entire population of Guangdong Province were summarized.Results:The estimated l/M ratios in Guangzhou(3.658),Zhongshan(2.153),and Sihui(1.527) were significantly different(P < 0.001),with an average l/M ratio of 2.446.Significant differences in the estimated l/M ratios were observed between distinct age groups and the three cancer registries.The estimated l/M ratio in females was significantly higher than that in males(2.864 vs.2.027,P < 0.001).It was estimated that there were 163,376 new cancer cases(99,689 males and 63,687 females) in 2009;it was further estimated that 115,049 people(75,054 males and 39,995females) died from cancer in Guangdong Province in 2009.The estimated crude and age-standardized rate of incidences(ASRI) in Guangdong Province were 231.34 and 246.87 per 100,000 males,respectively,and 156.98 and 163.57 per 100,000 females,respectively.The estimated crude and age-standardized rate of mortalities(ASRM) in Guangdong Province were 174.17 and 187.46 per 100,000 males,respectively,and 98.59 and 102.00 per 100,000 females,respectively.In comparison with the western area and the northern mountain area,higher ASRI and ASRM were recorded in the Pearl River Delta area and the eastern area in both males and females.Conclusions:Cancer imposes a heavy disease burden,and cancer patterns are unevenly distributed throughout Guangdong Province.More health resources should be allocated to cancer control,especially in the western and northern mountain areas.

Aberrant methylation and downregulation of sall3 in human hepatocellular carcinoma

AIM: To investigated whether sall3 transcription was regulated by promoter CpG island hypermethylation in hepatocellular carcinoma (HCC). METHODS: The cell lines Huh7, HepG2, SK-HEP1, SM-MC7721, Bel7402, QGY7703 and a cohort of 38 HCC tissue specimens and corresponding nontumorous tissues were subjected to analysis for sall3 promoter CpG island methylation and mRNA transcription. sall3 promoter CpG island methylation levels were determined using the MassARRAY platform and mRNA transcription levels of the gene were detected by quantitative realtime polymerase chain reaction.RESULTS: The levels of sall3 mRNA were decreased by more than twofold in 33 of 38 tumor tissues compared to adjacent noncancerous tissues. Among these 33 tumor tissues with lower levels of sall3 mRNA, 24 showed higher levels of methylation. Based on these results, we hypothesized that the decrease in sall3 mRNA transcription level was likely due to promoter CpG island hypermethylation. Changes in sall3 mRNA transcription and promoter CpG island methylation were determined in the above six cell lines after treatment with 0, 0.1, 0.5 and 2.5 mmol 5-aza-2-deoxycytidine, a demethylating agent. Promoter CpG island methylation levels de- creased in a dose-dependent manner in all six cell lines, while the mRNA transcription level increased dose-dependently in Huh7, HepG2, SK-HEP1 and SMMC7721 cells and irregularly in Bel7402 and QGY7703 cells. CONCLUSION: These results indicated that promoter CpG island hypermethylation contributes to the downregulation of sall3 mRNA transcription in HCC.

Simultaneous detection of enterovirus-D68 and vaccine-related poliovirus 3 in the stool samples of a 5-month hospitalized child with acute respiratory disease:A case report

Human enterovirus(EV)infections can lead to various manifestations,with variable correlations between genotypes and symptoms.Human enterovirus D68(EV-D68)was considered to be associated with acute respiratory disease and acute flaccid myelitis.In this short report,both EV-D68 and poliovirus 3 were detected in the stool of a hospitalized 5-month child who presented with acute respiratory symptoms and who was recently vaccinated with oral polio vaccine(OPV),using a metatranscriptomic high-throughput sequencing method.The nearly full-length genome sequences with complete open reading frames of EV-D68 and poliovirus 3 were assembled.One previously-reported neurovirulence-related amino acid substitution(T860N)in the EV-D68 VP1 region was observed,but the patient showed no neurological symptoms.More attention should be paid to EV-D68,and continuous multiple syndrome-based surveillance on non-polio enterovirus is called for.

Key Social Determinants to Narrow the Gap between Health-adjusted Life Expectancy and Life Expectancy in Megacities

Objective Improvement in the quality of life is reflected in the narrowing of the gap between healthadjusted life expectancy(HALE)and life expectancy(LE).The effect of megacity expansion on narrowing the gap is rarely reported.This study aimed to disclose this potential relationship.Methods Annual life tables were constructed from identified death records and population counts from multiple administrative sources in Guangzhou,China,from 2010 to 2020.Joinpoint regression was used to evaluate the temporal trend.Generalized principal component analysis and multilevel models were applied to examine the county-level association between the gap and social determinants.Results Although LE and HALE in megacities are increasing steadily,their gap is widening.Socioeconomic and health services are guaranteed to narrow this gap.Increasing personal wealth,a growing number of newborns and healthy immigrants,high urbanization,and healthy aging have helped in narrowing this gap.Conclusion In megacities,parallel LE and HALE growth should be highly considered to narrow their gap.Multiple social determinants need to be integrated as a whole to formulate public health plans.

Seroprevalence of human enterovirus A71 in Guangzhou,China,2019-2021

Enterovirus A71 (EV-A71) is a significant hand-foot-mouth disease (HFMD) etiology. The inactivated EV-A71 vaccines were approved in China in 2016. However, the seroprevalence of EV-A71 after the vaccine application and its potential association with the EV-A71 epidemic in the population are rarely studied. In this study, we analyzed the incidence of EV-A71 infection and seroepidemiology in Guangzhou City, China. From 2019 to 2021, 167,920 clinically confirmed HFMD cases were reported in Guangzhou. In 6,868 enterovirus-positive samples, Coxsackievirus A6 and Coxsackievirus A16 were dominant genotypes, and only 3 EV-A71-positive samples were detected, highlighting the deficient epidemic activity of EV-A71. Microneutralization assay was performed on 1,000 representative serum samples. Notably, the seroprevalence and geometric mean titer (GMT) decreased significantly in 2020, and that in the < 3-year age group were increased and even higher than that in 3–5-year age group in 2019 and 2021, which was contrary to our previous surveillance result and other studies in Guangzhou. Furthermore, a moderate decline of GMT level was observed following the vaccination, but the seropositive serums were still detected for 49 months after second immunization, suggesting the long-term persistence of the immunity. Our seroepidemiology study revealed relatively higher neutralizing antibody activity in the susceptible population after the EV-A71 vaccine was adopted in 2016 in Guangzhou. It may be one of the reasons for the lower epidemic activity of EV-A71 in Guangzhou from 2019 to 2021.