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Tuberculosis was ranked No. 3 among 29 types of infectious diseases in January 2022 of Jiangsu Province, in the southeast of China, and it has strong seasonality whose incidence rate has been high in springs and low in winters. This comprehensive study extends the spreading dynamics to the control strategies of TB in Jiangsu Province with time‐varying transmission rate, which is the first one in this type. The periodic transmission rate is incorporated to the classic SEIR model with susceptible, latent, infectious, and recovered compartments. The analysis shows that when the basic reproduction number R0$$ {R}_0 $$ is less than one, the epidemic will eventually disappear but, if R0$$ {R}_0 $$ is larger than one, the disease may persist with a periodic solution. The R0$$ {R}_0 $$ value of Jiangsu TB is calculated as 1.297. In addition, the model predicts that the epidemic will not disappear over time and there will be a major outbreak after certain years. To eradicate TB, this work introduces three control strategies on susceptible, latent, and infectious populations. It turns out that the optimal control solutions can reduce the incidence rate in 2035 by 90% from 2015, the goal of World Health Organization. Simultaneously, we find that the optimal controls have the same seasonality as the transmission rate. This indicates that Jiangsu Province needs to invest more control efforts in springs than in winters. In addition, the cost of control strategies is analyzed in terms of the unit cost, total cost, and incremental cost‐effectiveness. Summarizing all results, we recommend targeting the latent patients, or both latent and infectious individuals, with the transmission rate‐synchronized control strength as the most effective control strategy, to mitigate or even eradicate TB disease in Jiangsu Province. [ABSTRACT FROM AUTHOR]

Objective: To predict the trend of AIDS in specific age groups and to determine the objective population for AIDS screening, this study explored the three transmission routes and characterized each patient group using the APC model based on the whole, local, and immigrant populations in Zhejiang, China.Methods: The data recruited in this paper was obtained from the national Comprehensive AIDS Prevention and Control Information System - Antiviral Therapy Management database and the Chinese Disease Prevention and Control Information System and the Statistical Yearbook of Zhejiang, China. An APC model was used to estimate the impact of age, period, and cohort on the incidence of AIDS, as well as to predict the AIDS incidence in specific age groups based on different sexes with different transmission routes.Results: The AIDS incidence peaked in males aged 20-35 years; the incidence of males was higher than that of females due to the impact of period; obvious cohort effect was observed among the immigrants. In the whole and local populations, the incidences of males in all age groups and females in both the 35-year-old group and the whole age group were predicted to increase sharply in 5 years. In the immigrant population, the AIDS incidences in both sexes in all age groups were expected to increase significantly in 5 years. Under the influence of period, the incidence of AIDS via homosexual transmission in the whole population and the local population increased and remained stable after 2015. At the same time, the incidence of AIDS transmitted by homosexual and heterosexual routes in the immigrants also showed an increasing trend.Conclusions: The results elucidate that there are sex differences in AIDS incidence, and the incidence of AIDS through various transmission routes in all groups is predicted to exhibit an upward trend in the 5 years to come. Effective intervention strategies should be developed and implemented by the public health departments in Zhejiang to control the epidemic of AIDS. [ABSTRACT FROM AUTHOR]

Background: In infectious disease transmission dynamics, the high heterogeneity in individual infectiousness indicates that few index cases generate large numbers of secondary cases, which is commonly known as superspreading events. The heterogeneity in transmission can be measured by describing the distribution of the number of secondary cases as a negative binomial (NB) distribution with dispersion parameter, k. However, such inference framework usually neglects the under-ascertainment of sporadic cases, which are those without known epidemiological link and considered as independent clusters of size one, and this may potentially bias the estimates.Methods: In this study, we adopt a zero-truncated likelihood-based framework to estimate k. We evaluate the estimation performance by using stochastic simulations, and compare it with the baseline non-truncated version. We exemplify the analytical framework with three contact tracing datasets of COVID-19.Results: We demonstrate that the estimation bias exists when the under-ascertainment of index cases with 0 secondary case occurs, and the zero-truncated inference overcomes this problem and yields a less biased estimator of k. We find that the k of COVID-19 is inferred at 0.32 (95%CI: 0.15, 0.64), which appears slightly smaller than many previous estimates. We provide the simulation codes applying the inference framework in this study.Conclusions: The zero-truncated framework is recommended for less biased transmission heterogeneity estimates. These findings highlight the importance of individual-specific case management strategies to mitigate COVID-19 pandemic by lowering the transmission risks of potential super-spreaders with priority. [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]

This study aims to systematically review published literature on heterosexual transmission among HIV discordant couples in China. We conducted a systematic review and random-effects meta-analysis of 32 published articles in both Chinese and English. The summarized overall HIV seroconversion rate among discordant couples in China is 1.2 per 100 person-years (95% CI 0.9–1.7/100 PY). The overall estimate for HIV prevalence through heterosexual transmission in discordant couples is 11.5% (95% CI 8.2%–15.2%) in China. In a stratified meta-analysis by region, Henan province showed an HIV seroconversion rate of 0.9/100 PY (95% CI 0.6–1.2/100 PY) and an HIV prevalence rate of 3.9% (95% CI 2.5–5.7%). Yunnan province showed an HIV seroconversion rate of 1.7/100 PY (95% CI 1.2–2.3/100 PY) and an HIV prevalence rate of 17.0% (95% CI 13.7–20.6%). Other provinces collectively showed a HIV seroconversion rate of 3.9/100 PY (95% CI 1.0–8.7/100 PY) and an HIV prevalence rate of 21.5% (95% CI 9.6–36.5%). In a stratified meta-analysis by time, the subgroup from 1994 to 2004 had a seroconversion rate of 3.9/100 PY (95% CI 1.0–8.7/100 PY) and the subgroup from 2005 to 2011 had a seroconversion rate of 1.1/100 PY (95% CI 0.8–1.5/100 PY). These data show that China's free national HIV prevention and treatment program has been successful at limiting transmission in discordant couples. Because heterosexual transmission is now the dominant method of HIV transmission in China, it is important to understand seroconversion and prevalence rates in discordant couples to develop more effective prevention and treatment programs. [ABSTRACT FROM PUBLISHER]

• We developed a mobility network model for spatial epidemics. • The second outbreak occurred approximately on March 1, 2020. • By March 15, 2020, the cumulative cases increased by 70.6% without a travel ban. • The increase of cumulative cases is mainly caused by intra-province travel. • The strict travel ban successfully prevented a severe secondary wave in China. The ongoing COVID-19 pandemic expanded its geographic distribution through the movement of humans and caused subsequent local outbreaks. Hence, it is essential to investigate how human mobility and travel ban affect the transmission and spatial spread while minimizing the impact on social activities and national economics. We developed a mobility network model for spatial epidemics, explicitly taking into account time-varying inter-province and inner-province population flows, spatial heterogeneity in terms of disease transmission, as well as the impact of media reports. The model is applied to study the epidemic of the dynamic network of 30 provinces of mainland China. The model was calibrated using the publicly available incidence and movement data. We estimated that the second outbreak occurred approximately on February 24, 2020, and the cumulative number of cases as of March 15, 2020, increased by 290.1% (95% CI: (255.3%, 324.9%)) without a travel ban in mainland China (excluding Hubei and Tibet). We found that intra-province travel contributes more to the increase of cumulative number of cases than inter-province travel. Our quantitative and qualitative research results suggest that the strict travel ban has successfully prevented a severe secondary outbreak in mainland China, which provides solutions for many countries and regions experiencing secondary outbreaks of COVID-19. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we investigate the effect of the spatial heterogeneity on the extinction and persistence of the Zika virus (ZIKV) further. We define the basic reproduction number R 0 and prove that R 0 can be used to govern the threshold dynamics of the ZIKV: if R 0 < 1 , the unique disease-free equilibrium is globally asymptotic stable and the ZIKV will die out, while if R 0 > 1 , there is at least one endemic equilibrium and the ZIKV will persist uniformly. Via numerical simulations, we show the evolution of the spatial distribution of infected people and find that the final size of the infected people is 25,717, which agrees nearly with the real weekly reported case data 25,400 from November 1, 2015 to April 10, 2016 in Rio de Janeiro, Brazil. Highlights • A Zika virus (ZIKV) model with spatial heterogeneity is developed. • The threshold dynamics of the ZIKV model are given. • The spatial distribution and final size of the ZIKV are strongly dependent on the location when ZIKV appears in a region. • It is useful to understand the influences of spatial heterogeneity on the dynamics of ZIKV. [ABSTRACT FROM AUTHOR]

• We study the impact of supplementary immunization activities (SIAs) on the measles transmission dynamics and its implications for measles elimination goals in China. • The model takes into account population demographics, age-specific contact patterns, seasonality, routine vaccination, SIAs, and the waning vaccine-induced immunity. • SIAs have greatly reduced the measles incidence and the fraction of susceptibles, but the benefit may wane over time. Additional SIAs may accelerate the measles elimination. • The outbreak risk may be greater than 70% once the monthly imported measles cases exceed ten. Measles has re-emerged globally due to the accumulation of susceptible individuals and immunity gap, which causes challenges in eliminating measles. Routine vaccination and supplementary immunization activities (SIAs) have greatly improved measles control, but the impact of SIAs on the measles transmission dynamics remains unclear as the vaccine-induced immunity wanes. We developed a comprehensive measles transmission dynamics model by taking into account population demographics, age-specific contact patterns, seasonality, routine vaccination, SIAs, and the waning vaccine-induced immunity. The model was calibrated by the monthly age-specific cases data from 2005 to 2018 in Jiangsu Province, China, and validated by the dynamic sero-prevalence data. We aimed to investigate the short-term and long-term impact of three-time SIAs during 2009–2012 (9.68 million and 4.25 million children aged 8 months-14 years in March 2009 and September 2010, respectively, and 140,000 children aged 8 months-6 years in March 2012) on the measles disease burden and explored whether additional SIAs could accelerate the measles elimination. We estimated that the cumulative numbers of measles cases from March 2009 to December 2012 (in the short run) and to December 2018 (in the long run) after three-time SIAs (base case) were 6,699 (95% confidence interval [CI]: 2,928–10,469), and 22,411 (15,146–29,675), which averted 45.0% (42.9%-47.0%) and 34.3% (30.7%-37.9%) of 12,226 (4,916–19,537) and 34,274 (21,350–47,199) cases without SIAs, respectively. The fraction of susceptibles for children aged 8–23 months and 2–14 years decreased from 8.3% and 10.8% in March 2009 to 5.8% and 5.8% in April 2012, respectively. However, the fraction of susceptibles aged 15–49 years and above 50 years increased gradually to about 15% in 2018 irrespective of SIAs due to the waning immunity. The measles elimination goal would be reached in 2028, and administrating additional one-off SIAs in September 2022 to children aged 8–23 months, or young adolescents aged 15–19 years could accelerate the elimination one year earlier. SIAs have greatly reduced the measles incidence and the fraction of susceptibles, but the benefit may wane over time. Under the current interventions, Jiangsu province would reach the measles elimination goal in 2028. Additional SIAs may accelerate the measles elimination one year earlier. [ABSTRACT FROM AUTHOR]