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Background: Rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan, China, prompted heightened surveillance in Shenzhen, China. The resulting data provide a rare opportunity to measure key metrics of disease course, transmission, and the impact of control measures.Methods: From Jan 14 to Feb 12, 2020, the Shenzhen Center for Disease Control and Prevention identified 391 SARS-CoV-2 cases and 1286 close contacts. We compared cases identified through symptomatic surveillance and contact tracing, and estimated the time from symptom onset to confirmation, isolation, and admission to hospital. We estimated metrics of disease transmission and analysed factors influencing transmission risk.Findings: Cases were older than the general population (mean age 45 years) and balanced between males (n=187) and females (n=204). 356 (91%) of 391 cases had mild or moderate clinical severity at initial assessment. As of Feb 22, 2020, three cases had died and 225 had recovered (median time to recovery 21 days; 95% CI 20-22). Cases were isolated on average 4·6 days (95% CI 4·1-5·0) after developing symptoms; contact tracing reduced this by 1·9 days (95% CI 1·1-2·7). Household contacts and those travelling with a case were at higher risk of infection (odds ratio 6·27 [95% CI 1·49-26·33] for household contacts and 7·06 [1·43-34·91] for those travelling with a case) than other close contacts. The household secondary attack rate was 11·2% (95% CI 9·1-13·8), and children were as likely to be infected as adults (infection rate 7·4% in children <10 years vs population average of 6·6%). The observed reproductive number (R) was 0·4 (95% CI 0·3-0·5), with a mean serial interval of 6·3 days (95% CI 5·2-7·6).Interpretation: Our data on cases as well as their infected and uninfected close contacts provide key insights into the epidemiology of SARS-CoV-2. This analysis shows that isolation and contact tracing reduce the time during which cases are infectious in the community, thereby reducing the R. The overall impact of isolation and contact tracing, however, is uncertain and highly dependent on the number of asymptomatic cases. Moreover, children are at a similar risk of infection to the general population, although less likely to have severe symptoms; hence they should be considered in analyses of transmission and control.Funding: Emergency Response Program of Harbin Institute of Technology, Emergency Response Program of Peng Cheng Laboratory, US Centers for Disease Control and Prevention. [ABSTRACT FROM AUTHOR]

Background: The epidemic of hand, foot, and mouth disease (HFMD) has become a severe public health problem in the world and has also brought a high economic and health burden. Furthermore, the prevalence of HFMD varies significantly among different locations. However, there have been few investigations of the effects of socioeconomic factors and air pollution factors on the incidence of HFMD. Methods: This study collected data on HFMD in Shenzhen, China, from 2012 to 2015. We selected eleven factors as potential risk factors for HFMD. A Bayesian spatiotemporal model was used to quantify the influence of the factors on HFMD and to identify the relative risks in different districts. Results: The risk factors of HFMD were the population, population density, concentration of SO2, and concentration of NO2. The relative risks (RRs) were 1.00473 (95% CI: 1.00059–1.00761), 1.00010 (95% CI: 1.00002–1.00016), 1.00215 (95% CI: 1.00170–1.00232) and 1.00058 (95% CI: 1.00028–1.00078), respectively. The protective factors against HFMD were the per capita GDP, the number of public kindergartens, the concentration of PM10, and the concentration of O3. The RRs were 0.98840 (95% CI: 0.98660–0.99026), 0.97686 (95% CI: 0.96946–0.98403), 0.99108 (95% CI: 0.98551–0.99840) and 0.99587 (95% CI: 0.99534–0.99610), respectively. The risk of incidence in Longgang district and Pingshan district decreased, while the risk of incidence in Baoan district increased. Conclusions: Studies have confirmed that socioeconomic factors and air pollution factors have an impact on the incidence of HFMD in Shenzhen, China. The results will be of great practical significance to local authorities, which is conducive to accurate prevention and can be used to formulate HFMD early warning systems. Author summary: This study used Bayesian spatiotemporal modelling to analyze the factors that influence the incidence of hand, foot, and mouth disease (HFMD)in Shenzhen, including socioeconomic factors and air pollution factors. A total of 171,210 HFMD cases and socioeconomic and air pollution data from 2012–2015 were included in the analysis. Studies have confirmed that socioeconomic factors and air pollution factors affect the risk of HFMD in Shenzhen, China. By testing the optimal model, the relative risk map of each area was drawn to identify the high-risk areas of HFMD and the future trends of the disease. The results will be of great practical significance to local authorities, which is conducive to accurate prevention and can be used to formulate targeted disease intervention measures. [ABSTRACT FROM AUTHOR]

Though inconsistent, acute effects of ambient nitrogen oxides on cardiovascular mortality have been reported. Whereas, interactive roles of temperature on their relationships and joint effects of different indicators of nitrogen oxides were less studied. This study aimed to extrapolate the independent roles of ambient nitrogen oxides and temperature interactions on cardiovascular mortality. Data on mortality, air pollutants, and meteorological factors in Shenzhen from 2013 to 2019 were collected. Three indicators including nitric oxide (NO), nitrogen dioxide (NO 2), and nitrogen oxides (NO X) were studied. Adjusted generalized additive models (GAMs) were applied to analyse their associations with cardiovascular mortality in different groups. The average daily concentrations of NO, NO 2 , and NO X were 11.7 μg/m3, 30.7 μg/m3, and 53.2 μg/m3, respectively. Significant associations were shown with each indicator. Cumulative effects of nitrogen oxides were more obvious than distributed lag effects. Males, population under 65 years old, and population with stroke-related condition were more susceptible to nitrogen oxides. Adverse effects of nitrogen oxides were more significant at low temperature. Impacts of NO 2 on cardiovascular mortality, and NO on stroke mortality were the most robust in the multi-pollutant models, whereas variations were shown in the other relationships. Low levels of nitrogen oxides showed acute and adverse impacts and the interactive roles of temperature on cardiovascular mortality. Cumulative effects were most significant and joint effects of nitrogen oxides required more attention. Population under 65 years old and population with stroke-related health condition were susceptible, especially days at lower temperature. [Display omitted] • Shenzhen was lightly polluted by nitrogen oxides from 2013 to 2019. • Low levels of nitrogen oxides affected adversely on cardiovascular mortality. • Cumulative effects of nitrogen oxides were most significant. • The adverse effects of nitrogen oxides were more obvious at lower temperature. • Joint effects were shown when different types of nitrogen oxides were combined. [ABSTRACT FROM AUTHOR]

• Multilevel regression model was used to correlate the mortality and park equality. • Park accessibility has stronger correlation with mortality compared to green space. • The greater park accessibility is associated with a lower mortality. • This negative correlation disappears when accessibility exceeds 47.72 m2/person. • Moderate park constructions are suggested for balancing public health and land use. Numerous studies have revealed that accessible parks are associated with better health outcomes. This interdisciplinary study focuses the spatial equality of local parks in Shenzhen, China, and aims to investigate its correlation with the summation of mortalities for the top four causes of non-accidental death. The paper consists of two parts: firstly, the spatial equality of parks was assessed by several criteria including the Gini index and accessibility calculated by the Gaussian-based two-step-floating catchment area (G2SFCA) method, and then multilevel regression analysis was novelly used to explore the correlation between the equality of park and mortality integrated with geodemographic and economic factors. The results show that the residents living in city centre experience higher accessibility and more equality of parks. There is greater equality regarding neighbourhood parks provision than urban parks provision. Parks that are walking accessible have stronger correlations with mortality compared to all types of green spaces. Most importantly, the greater park accessibility is associated with a lower mortality whereas this relation no longer exists when the accessibility exceeds 47.72m2/person, which is concluded that building parks moderately is suggested to balance the health benefits and land scarcity for the sustainable development of cities. [ABSTRACT FROM AUTHOR]