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The differences of SARS-CoV-2 variants brought the changes of transmission characteristics and clinical manifestations during the prevalence of COVID-19. In order to explore the evolution mechanisms of SARS-CoV-2 variants and the impacts of variant evolution, the classic SIR (Susceptible-Infected-Recovered) compartment model was modified to a generalized SVEIR (Susceptible-Vaccinated-Exposed-Infected-Recovered) compartment model with age-group and varying variants in this study. By using of the SVEIR model and least squares method, the optimal fittings against the surveillance data from Fujian Provincial Center for Disease Control and Prevention were performed for the five epidemics of Fujian Province. The main epidemiological characteristics such as basic reproduction number, effective reproduction number, sensitivity analysis, and cross-variant scenario investigations were extensively investigated during dynamic zero-COVID policy. The study results showed that the infectivities of the variants became fast from wild strain to the Delta variant, further to the Omicron variant. Meanwhile, the cross-variant investigations showed that the average incubation periods were shortened, and that the infection scales quickly enhanced. Further, the risk estimations with the new variants were performed without implements of the non-pharmaceutical interventions, based on the dominant variants XBB.1.9.1 and EG.5. The results of the risk estimations suggested that non-pharmaceutical interventions were necessary on the Chinese mainland for controlling severe infections and deaths, and also that the regular variant monitors were still workable against the aggressive variant evolution and the emergency of new transmission risks in the future. [ABSTRACT FROM AUTHOR]

Background: Severe fever with thrombocytopenia syndrome (SFTS) was listed as one of the most severe infectious disease by world health organization in 2017. It can mostly be transmitted by tick bite, while human-to-human transmission has occurred on multiple occasions. This study aimed to explore the epidemiological and clinical characteristics and make risk analysis of SFTS human-to-human transmission. Methods: Descriptive and spatial methods were employed to illustrate the epidemiological and clinical characteristics of SFTS human-to-human transmission. The risk of SFTS human-to-human transmission was accessed through secondary attack rate (SAR) and basic reproductive number (R0). Logistic regression analysis was used to identify the associated risk factors. Results: A total of 27 clusters of SFTS human-to-human transmission were reported in China and South Korea during 1996–2019. It mainly occurred among elder people in May, June and October in central and eastern China. The secondary cases developed milder clinical manifestation and better outcome than the index cases. The incubation period was 10.0 days (IQR:8.0–12.0), SAR was 1.72%-55.00%, and the average R0 to be 0.13 (95%CI:0.11–0.16). Being blood relatives of the index case, direct blood/bloody secretion contact and bloody droplet contact had more risk of infection (OR = 6.35(95%CI:3.26–12.37), 38.01 (95%CI,19.73–73.23), 2.27 (95%CI,1.01–5.19)). Conclusions: SFTS human-to-human transmission in China and South Korea during 1996–2019 had obvious spatio-temporal distinction. Ongoing assessment of this transmission risk is crucial for public health authorities though it continues to be low now. Author summary: This study is first to explore the epidemiological and clinical characteristics of SFTS human-to-human transmission. We found SFTS human-to-human transmission had obvious characteristic temporal and spatial distinction, which mainly occurred among elder people in May, June and October in the central and eastern China. The secondary cases developed milder clinical manifestation and better outcome than the index cases. The incubation period was 10.0 days (IQR:8.0–12.0). The risk of SFTS human-to-human transmission continues to be low, with the secondary attack rate (SAR) among humans was 1.72%-55.00% and basic reproductive number (R0) to be 0.13 (95%CI:0.11–0.16). Being blood relatives of the index case, direct blood/bloody secretion contact and bloody droplet contact had more risk of acquiring infection. [ABSTRACT FROM AUTHOR]

Background: Data was limited on prevalence of overweight and obesity among primary school-aged children in Jiangsu Province. We aimed to present the current situation of obesity in Jiangsu Province and explore the relationship between obesity and other common diseases in children. Methods: Physical examination among children aged 7 to 14 years in Jiangsu Province was conducted since 2014, and more than one third primary schools were covered annually. The physical measurements included body height, weight, blood pressure, vision, sex, age, and so on. Results: The prevalence of overweight and obesity among primary school children was 15.2% (18.7% for male students and 11.0% for female students), and 11.7% (14.5% for male students and 8.2% for female students) respectively. Obesity/overweight prevalence varied by regions. Among them the lowest prevalence was found in the southern region of Jiangsu Province, where residents had the highest average income level. Obesity group had elevated blood pressure comparing with the normal group, and obesity group especially in the male children aged 7 to 12 years had a higher prevalence of uncorrected visual acuity (UCVA) than that of normal group. Conclusion: This study found that obesity/overweight prevalence differed by sex, age, and regions in Jiangsu Province. In addition, obese children were closely associated with other common disease. Further studies are needed to explore the basis of biological and statistical theories. [ABSTRACT FROM AUTHOR]

Objectives: To identify specific clinical and epidemiological parameters for clinical diagnosis of SFTSV infection with relatively higher accuracy. Methods: 231 suspected cases of SFTS were reported by various medical institutions from 2011 to 2013 in Jiangsu Province, China. They were followed with SFTSV diagnosis tests and interview-administered questionnaires about demographic characteristics, clinical symptoms and epidemiological exposure factors. Univariate and multivariable logistic regression analysis were used to examine the diagnostic value of these parameters. Results: SFTSV infection occurred only from April to October annually and usually in hilly areas of specific regions. Three prediction models of SFTSV infection were constructed. Model 3 with clinical and epidemiological parameters combined the benefits of both Model 1and Model 2, which was optimal and had an overall accuracy of 80.2%. Independent indicators for clinical diagnosis of SFTSV infection in Model 3 were as follows: lymphadenopathy (P = 0.01), leucopenia (P<0.01), age >50 years (P = 0.01), tick bites (P<0.01), raising domestic animals in the residential areas (P<0.01) and farming (P = 0.03). Conclusions: Our results show that using a combination of clinical and epidemiological parameters may be a feasible strategy to provide preliminary fast diagnosis as differentiating SFTSV infection from SFTS-like diseases, thus reducing the risk of misdiagnosis. [ABSTRACT FROM AUTHOR]

Having a thorough understanding of the infectivity of HIV, time of initiating treatment and emergence of drug resistant virus variants is crucial in mitigating HIV infection. There are many challenges to evaluating the long-term effect of the Highly Active Antiretroviral Therapy (HAART) on disease transmission at the population level. We proposed an individual based model by coupling within-host dynamics and between-host dynamics and conduct stochastic simulation in the group of men who have sex with men (MSM). The mean actual reproduction number is estimated to be 3.6320 (95% confidence interval: [3.46, 3.80]) for MSM group without treatment. Stochastic simulations show that given relatively high (low) level of drug efficacy after emergence of drug resistant variants, early initiation of treatment leads to a less (greater) actual reproduction number, lower (higher) prevalence and less (more) incidences, compared to late initiation of treatment. This implies early initiation of HAART may not always lower the actual reproduction number and prevalence of infection, depending on the level of treatment efficacy after emergence of drug resistant virus variants, frequency of high-risk behaviors and etc. This finding strongly suggests early initiation of HAART should be implemented with great care especially in the settings where the effective drugs are limited. Coupling within-host dynamics with between-host dynamics can provide critical information about impact of HAART on disease transmission and thus help to assist treatment strategy design and HIV/AIDS prevention and control. [ABSTRACT FROM AUTHOR]

Background: Since China has a unique system of delivering HIV care that includes all patients’ records. The factors related to CD4+ T-cell recovery and viral suppression in patients who have low CD4+ T cell counts at the initiation of HAART are understudied in the China despite subsequent virological suppression (viral load < 50 copies/mL) is unknown. Methods: The authors conducted a retrospective cohort study using data from the national HIV treatment sub-database of Zhejiang province to identify records of HIV+ patients. Patient records were included if they were ≥ 16 years of age, had an initial CD4 count < 100 cells/μL, were on continuous HAART for at least one year by the end of December 31, 2014; and achieved and maintained continued maximum virological suppression (MVS) (< 50 copies/ml) by 9 months after starting HAART. The primary endpoint for analysis was time to first CD4+ T cell count recovery (≥ 200, 350, 500 cells/μL). Cox proportional hazard regression was used to identify the risk factors for CD4+ T cell count recovery to key thresholds (200–350, 350–500, ≥ 500 cells/μL) by the time of last clinical follow-up (whichever occurred first), key thresholds (follow-up date for analysis), with patients still unable to reach the endpoints being censored by the end December 31, 2014 (follow-up date for analysis). Results: Of the 918 patients who were included in the study, and the median CD4+ T cell count was 39 cells/μL at the baseline. At the end of follow-up, 727 (79.2%), 363 (39.5%) and 149 (16.2%) patients had return to ≥ 200, 350, and 500 cells/μL, respectively. Kaplan-Meier analysis demonstrated that the rate of patients with CD4+ count recovery to ≥ 200, 350, and 500 cells/μL after 1 year on HAART was 43.6, 8.6, and 2.5%, respectively, after 3 years on treatment was 90.8, 46.3, and 17.9%, respectively, and after 5 years on HAART was 97.1, 72.2, and 36.4%, respectively. The median time to return to 200–350, 350–500, ≥ 500cells/μL was 1.11, 3.33 and 6.91 years, respectively. Factors of age (aHR = 0.77, 95%CI 0.61–0.97), baseline CD4+ count (aHR = 1.60, 95%CI 1.37–1.86), initial regimens, changes in regimen (aHR = 0.58, 95%CI 0.49–0.69), and inclusion of a cotrimoxazole prophylaxis (aHR = 0.66, 95%CI 0.51–0.85) were associated with CD4+ T cell count recovery. Conclusion: The proportion of patients with initially low CD4 counts after nine months of treatment and that achieved continuous virological suppression was greater than 70% for persons with CD4+ count ≥ 350. Conversely, only 35% of patients recovered to levels of 500 cells/μL after 5 years of treatment, and levels continued to rise significantly with further long-term HAART. Early HAART intervention will be necessary for achieving effective CD4+ T cell responses and optimal immunological function in HIV+ patients. [ABSTRACT FROM AUTHOR]

Hand, foot and mouth disease (HFMD) is an important public health issue in mainland China, including Jiangsu Province. The main purpose of this study was to depict the epidemiological characteristics of HFMD and evaluate the effects of meteorological variables on its dynamics via spatiotemporal analytic methods, which is essential for formulating scientific and effective prevention and control strategies and measures. In total, 497,910 cases of HFMD occurred in the 2009-2013 period, with an average annual incidence of 126.3 per 100,000 in Jiangsu. Out of these, 87.7% were under 5 years old with a male-to-female incidence ratio of 1.4. The dominant pathogens of the laboratory-confirmed cases were EV71 and CoxA16, accounting for 44.8% and 30.6% of all cases, respectively. Two incidence peaks were observed in each year, the higher occurring between April and June, the lower between November and December. The incidence ranged between 16.8 and 233.5 per 100,000 at the county level. The incidence in the South of the province was generally higher than that in the northern regions. The most likely spatiotemporal cluster detected by space–time scan analysis occurred in May-June of 2012 in the southern region. Average temperature and rainfall were positively correlated with HFMD incidence, while the number of days with rainfall ≥ 0.1mm, low temperature, high temperature and hours of sunshine were negatively related. Particularly, relative humidity had no relationship. In conclusion, the prevalence of HFMD in Jiangsu Province has an obvious feature of seasonality. The etiological composition changed dynamically and might be a latent driving force for the temporal variation of the incidence of HFMD. A moderately warm environment promotes the transmission of the HFMD viruses, while particularly cold and hot climate conditions restrain their transmission. [ABSTRACT FROM AUTHOR]

Background: Many Burmese women have migrated to Yunnan Province and married local residents over the past few decades; however, limited information is available on their HIV prevalence and ability to cope with HIV. This study aims to assess the prevalence of HIV and knowledge related to AIDS, as well as to discover possible risk factors of HIV infection among foreign brides from Burma in Yunnan Province. Methods: A cross-sectional study was taken of all Burmese cross-border wives residing in Tengchong County using standardized questionnaires. HIV and syphilis testing was conducted at the same time. Results: Among 600 Burmese brides, the HIV prevalence was 2.17%. Those aged 21–30, those with higher education levels and those who had resided in China less than one year had higher infection rates. The AIDS awareness rate of 39.50% was very low in this population. Only 28.67% of participants had ever been involved in prevention services. The rate of condom use was low. Classification by age, education, occupation, prior HIV testing and prior use of HIV prevention services showed a statistically significant association with mean knowledge score (p<0.05). Residing in China less than one year (OR = 3.86, 95% CI = 1.09–13.70) and having casual sex in the last year (OR = 10.49, 95% CI = 1.20–91.59) were risk factors for HIV infection. Conclusions: Burmese brides in China are not only exposed to a high risk of HIV infection, but also seriously lack response capabilities. Educational interventions and control efforts are practical approaches that need to be strengthened among this population. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic fever with renal syndrome (HFRS) is endemic in mainland China, accounting for 90% of total reported cases worldwide, and Jiangsu is one of the most severely affected provinces. In this study, the authors conducted GIS-based spatial analyses in order to determine the spatial distribution of the HFRS cases, identify key areas and explore risk factors for public health planning and resource allocation. Methods: Interpolation maps by inverse distance weighting were produced to detect the spatial distribution of HFRS cases in Jiangsu from 2001 to 2011. Spatio-temporal clustering was applied to identify clusters at the county level. Spatial correlation analysis was conducted to detect influencing factors of HFRS in Jiangsu. Results: HFRS cases in Jiangsu from 2001 to 2011 were mapped and the results suggested that cases in Jiangsu were not distributed randomly. Cases were mainly distributed in northeastern and southwestern Jiangsu, especially in Dafeng and Sihong counties. It was notable that prior to this study, Sihong county had rarely been reported as a high-risk area of HFRS. With the maximum spatial size of 50% of the total population and the maximum temporal size of 50% of the total population, spatio-temporal clustering showed that there was one most likely cluster (LLR = 624.52, P<0.0001, RR = 8.19) and one second-most likely cluster (LLR = 553.97, P<0.0001, RR = 8.25), and both of these clusters appeared from 2001 to 2004. Spatial correlation analysis showed that the incidence of HFRS in Jiangsu was influenced by distances to highways, railways, rivers and lakes. Conclusion: The application of GIS together with spatial interpolation, spatio-temporal clustering and spatial correlation analysis can effectively identify high-risk areas and factors influencing HFRS incidence to lay a foundation for researching its pathogenesis. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to describe the spatial and temporal trends of Shigella incidence rates in Jiangsu Province, People's Republic of China. It also intended to explore complex risk modes facilitating Shigella transmission. Methods: County-level incidence rates were obtained for analysis using geographic information system (GIS) tools. Trend surface and incidence maps were established to describe geographic distributions. Spatio-temporal cluster analysis and autocorrelation analysis were used for detecting clusters. Based on the number of monthly Shigella cases, an autoregressive integrated moving average (ARIMA) model successfully established a time series model. A spatial correlation analysis and a case-control study were conducted to identify risk factors contributing to Shigella transmissions. Results: The far southwestern and northwestern areas of Jiangsu were the most infected. A cluster was detected in southwestern Jiangsu (LLR = 11674.74, P<0.001). The time series model was established as ARIMA (1, 12, 0), which predicted well for cases from August to December, 2011. Highways and water sources potentially caused spatial variation in Shigella development in Jiangsu. The case-control study confirmed not washing hands before dinner (OR = 3.64) and not having access to a safe water source (OR = 2.04) as the main causes of Shigella in Jiangsu Province. Conclusion: Improvement of sanitation and hygiene should be strengthened in economically developed counties, while access to a safe water supply in impoverished areas should be increased at the same time. [ABSTRACT FROM AUTHOR]

Objective: The goal of this study was to understand the knowledge about AIDS, identify the correlates and determine the prevalence of HIV infection, syphilis, HCV among migrant workers in Zhejiang, China. Methods: A cross-sectional study using face-to-face anonymous questionnaire interviews was conducted and blood samples were collected for HIV, syphilis and Hepatitis C infection screening. Results: 17,377 (92.8%) of 18,730 migrant workers approached were interviewed. Among 17,377 participants, the HIV/AIDS knowledge rate was 66.2%. A total of 12,694 (73%) of the participants reported having ever had sexual intercourse, with 30.1% of single participants reporting having had sexual intercourse. Among those respondents with sexual experiences, 7.5% admitted they had two or more sexual partners and 4.9% reported having had sex with casual (unpaid) partners in the previous 12 months, whilst 3.7% had paid for sex. More than half of those who had paid for sex (59.4%) had not used a condom every time in their sexual acts with the sex workers. Multiple logistic regression analysis indicated that high risk sexual behavior (defined as sex with a casual or commercial sex partner without using a condom consistently) was associated with being divorced or widowed (P<0.05 for single); male gender; shorter duration of stay in Zhejiang; working in factory, market or domestic service (P<0.05 for odd job); having a province of origin inside Zhejiang; and drug use. The prevalence of HIV and HCV infections were 0.02% (95% CI: 0.01%–0.06%) and 0.40% (95%CI: 0.31%–0.51%), respectively. The prevalence of syphilis among those who were sexually active was 0.55% (95% CI: 0.43%–0.70%). Risk factors for syphilis included shorter duration of stay in Zhejiang, ethnic minority status, being divorced or widowed and having had multiple sex partners. Conclusions: Much greater efforts are needed to promote safer sex, and programs for the control of syphilis need to be tailored for migrant workers in China. [ABSTRACT FROM AUTHOR]

Family based association study (FBAS) has the advantages of controlling for population stratification and testing for linkage and association simultaneously. We propose a retrospective multilevel model (rMLM) approach to analyze sibship data by using genotypic information as the dependent variable. Simulated data sets were generated using the simulation of linkage and association (SIMLA) program. We compared rMLM to sib transmission/disequilibrium test (S-TDT), sibling disequilibrium test (SDT), conditional logistic regression (CLR) and generalized estimation equations (GEE) on the measures of power, type I error, estimation bias and standard error. The results indicated that rMLM was a valid test of association in the presence of linkage using sibship data. The advantages of rMLM became more evident when the data contained concordant sibships. Compared to GEE, rMLM had less underestimated odds ratio (OR). Our results support the application of rMLM to detect gene-disease associations using sibship data. However, the risk of increasing type I error rate should be cautioned when there is association without linkage between the disease locus and the genotyped marker.

Objective: This study aimed to describe the spatial and temporal trends of Shigella incidence rates in Jiangsu Province, People's Republic of China. It also intended to explore complex risk modes facilitating Shigella transmission., Methods: County-level incidence rates were obtained for analysis using geographic information system (GIS) tools. Trend surface and incidence maps were established to describe geographic distributions. Spatio-temporal cluster analysis and autocorrelation analysis were used for detecting clusters. Based on the number of monthly Shigella cases, an autoregressive integrated moving average (ARIMA) model successfully established a time series model. A spatial correlation analysis and a case-control study were conducted to identify risk factors contributing to Shigella transmissions., Results: The far southwestern and northwestern areas of Jiangsu were the most infected. A cluster was detected in southwestern Jiangsu (LLR = 11674.74, P<0.001). The time series model was established as ARIMA (1, 12, 0), which predicted well for cases from August to December, 2011. Highways and water sources potentially caused spatial variation in Shigella development in Jiangsu. The case-control study confirmed not washing hands before dinner (OR = 3.64) and not having access to a safe water source (OR = 2.04) as the main causes of Shigella in Jiangsu Province., Conclusion: Improvement of sanitation and hygiene should be strengthened in economically developed counties, while access to a safe water supply in impoverished areas should be increased at the same time.

Background: The study was to investigate the incidence of HIV-1 and related factors, as well as predictors associated with retention in a cohort study among men who have sex with men (MSM) in Yangzhou, Jiangsu Province, China. A carefully designed 12-month prospective cohort study was conducted., Methodology/principal Findings: A total of 278 sero-negative MSM were recruited and followed up for 12 months starting from May, 2008. Participants were tested for HIV-1 at baseline, 6-month, and 12-month follow-up visits. Questionnaire interviews were conducted to collect information. The retention rate and HIV incidence were analyzed as functions of demographic and behavioral variables. Risk factors were identified by estimating the relative risks (RR) and respective 95% confidence intervals (CI) using a Poisson regression model, univariate and multivariate analyses and risk factors analyses. 71 (25.5%) and 45 (16.2%) of the 278 participants were retained at the 6-month and 12-month follow-up visits respectively. The incidence rates of HIV-1 were 5.65 and 6.67 per 100 person years (PY) respectively. Both having received condoms and having received lubricant were negatively associated with HIV sero-conversion at the 12 months' follow-up. Predictors associated with 12-month retention rate include Yangzhou residency (RR=0.471, 95%CI: 0.275~0.807, P=0.006), having received condoms (RR=0.065, 95%CI: 0.007~0.572, P=0.014), and having received VCTs (RR=0.093, 95%CI: 0.010~0.818, P=0.032)., Conclusions/significance: The incidence of HIV-1 among MSM in Yangzhou is relatively high and effective interventions are needed urgently. More attention should be focused on maintaining a higher retention rate.

Family based association study (FBAS) has the advantages of controlling for population stratification and testing for linkage and association simultaneously. We propose a retrospective multilevel model (rMLM) approach to analyze sibship data by using genotypic information as the dependent variable. Simulated data sets were generated using the simulation of linkage and association (SIMLA) program. We compared rMLM to sib transmission/disequilibrium test (S-TDT), sibling disequilibrium test (SDT), conditional logistic regression (CLR) and generalized estimation equations (GEE) on the measures of power, type I error, estimation bias and standard error. The results indicated that rMLM was a valid test of association in the presence of linkage using sibship data. The advantages of rMLM became more evident when the data contained concordant sibships. Compared to GEE, rMLM had less underestimated odds ratio (OR). Our results support the application of rMLM to detect gene-disease associations using sibship data. However, the risk of increasing type I error rate should be cautioned when there is association without linkage between the disease locus and the genotyped marker.

Background: Several recent reports have demonstrated that tyrosine (Y)-methionine (M)-aspartic acid (D)-aspartic acid (D) (YMDD) motif mutations can naturally occur in chronic HBV patients without antiviral treatment such as lamivudine therapy. This paper aims to assess the overall spontaneous incidence and related risk factors of YMDD-motif mutations among lamivudine-naïve chronic HBV carriers, so as to provide some clue for clinical treatment of hepatitis B., Methodology/principal Findings: Chinese and English literatures were searched for studies reporting natural YMDD mutations among untreated chronic HBV patients from 2001 to 2010. The incidence estimates were summarized and analyzed by meta-analyses. Forty-seven eligible articles from eight countries were selected in this review (13 in English and 34 in Chinese). The pooled incidence of YMDD-motif mutation among untreated chronic HBV patients from eight countries was 12.21% (95% CI: 9.69%-14.95%). China had an incidence of 13.38% (95% CI: 10.90%-16.07%) and seven other countries had an incidence of 9.90% (95% CI: 3.28%-19.55%), respectively. Lamivudine therapy would increase the risk of mutations 5.23 times higher than the untreated patients. A higher HBV DNA copy number was associated with increased incidence of natural YMDD mutation. No significant difference was found in YMDD mutation incidence between groups of different gender, age, HBeAg status, patients' ALT (alanine aminotransferase) level, and between the groups of HBV genotype B and C., Conclusions: The YMDD-motif mutations can occur spontaneously with a relatively high incidence in CHB patients untreated with lamivudine. These mutations might be the consequence of accumulated base mismatch due to the nature of viral polymerase. More fundamental and clinical studies are needed to clarify the influence of YMDD mutations in hepatitis B progression and antiviral treatment.