Construction of SEIQCR epidemic model and its application in the evaluation of public health interventions on COVID-19 in Guangzhou. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective To develop a dynamic model of susceptible(S), exposed people in the latent period(E), infective(I), quarantined(Q), confirmed(C), and recovered(R)(SEIQCR)to evaluate the role of interventions and control the coronavirus disease 2019(COVID-19)epidemic in Guangzhou. Methods Based on the SEIR propagation dynamics model, the modules of "quarantined" and "confirmed" cases were added to establish a new SEIQCR model. The epidemic data in Guangzhou from Jan. 13 to Mar. 17, 2020 were fitted to obtain the parameters of SEIQCR model. Results The number of predicted cases based on these parameters was highly consistent with the actual incidence(R2=0.93). Time-dependent reproduction number declined rapidly with the implementation of first level response to COVID-19, indicating that local transmission was effectively controlled. Conclusion The preventative and control measures were effective. Local government should continue strictly implementing the isolation system and cut off the transmission channels to curb the transmission of COVID-19. The SEIQCR model can provide methodological reference for intervention assessment in other regions.

Prevalence and Predictors of PTSD During the Initial Stage of COVID-19 Epidemic among Female College Students in China.

BACKGROUND: College students are vulnerable and may experience high stress due to COVID-19, especially girls. This study aims to identify posttraumatic stress disorder (PTSD) and related factors among the target population during the initial phases of the COVID-19 pandemic. METHODS: In the initial phase of COVID-19 epidemic (February 23 to March 5, 2020), 2205 female college students from six provinces in mainland China were enrolled in this study and completed the online survey about the cognitive status of COVID-19, including the Impact of Event Scale-6, the Multidimensional Perceived Social Support Scale and a self-developed 10-item Perceived threat scale. Univariate and multivariate logistic regression were performed using SPSS software to explore the determinants of PTSD symptoms. RESULTS: PTSD symptoms were prevalent in female college students, and 34.20% met the cut-off for PTSD. Self-reported fair or poor health (AOR = 1.78, 95% CI: 1.22-2.59), high concern about COVID-19 (AOR = 1.66, 95% CI: 1.35-2.03), beliefs that "COVID-19 can cause a global outbreak" (AOR = 1.26, 95% CI: 1.02-1.56), the perception of "risk of infection" (AOR = 2.46, 95% CI: 2.16-2.81), beliefs that "closed management" and "COVID-19 as a public health emergency of international concern" would have an impact, and the fear of "impact on life planning" were all positively associated with PTSD (AOR = 1.37, 1.22, and 1.29, respectively); however, perceived social support from family (AOR = 0.81, 95% CI: 0.70-0.93) was negatively associated with PTSD. Among the significant variables at the bivariate level, multivariate logistic regression revealed that the greatest protector for PTSD was the high knowledge score (AOR = 0.73, 95% CI: 0.60-0.90), while had confirmed cases among relatives and friends (AOR = 7.70, 95% CI: 1.28-46.25) was the strongest predictor of PTSD. CONCLUSIONS: In summary, PTSD symptoms were prevalent among female college students in China during the COVID-19 epidemic. Targeting vulnerable populations to improve their knowledge about COVID-19 and create an atmosphere of social support would be beneficial. Moreover, the joint efforts from family, school administrators, and policymakers are essential to improve the mental health of the female students during the COVID-19 epidemic.

Impact of the COVID−19 Pandemic on Farm Households’ Vulnerability to Multidimensional Poverty in Rural China

The COVID−19 pandemic has significantly impacted the economy and livelihoods of people worldwide. To analyze the impact of the pandemic on material conditions, income levels, health conditions, industrial development and employment opportunities of farmers in China’s rural areas, especially poor areas and explore whether farmers can achieve stable poverty eradication during the COVID−19 pandemic, we interviewed 2662 farm households in poverty−stricken areas of China and used the multidimensional poverty measurement model, three−step feasible generalized least squares and propensity score matching to analyze data. We achieved the following results. First, the overall level of multidimensional poverty vulnerability index (MPVI) of the surveyed households was low and the MPVI of each dimension varied significantly. The MPVI of households in the treated group was higher than that of the control group. Second, COVID−19 increased farm households’ vulnerability to multidimensional poverty in poverty−stricken regions;MPVI increased by 27.9%. Third, COVID−19′s impact on various dimensions differed: the greatest impact was on the vulnerability to health deprivation, followed by industrial development, employment and income deprivation. However, the pandemic slightly reduced the vulnerability to material deprivation. Finally, we proposed various measures in response to the impact of the pandemic to assist farm households in poverty−stricken areas.

Impacts of transportation and meteorological factors on the transmission of COVID-19.

The ongoing pandemic of 2019 novel coronavirus disease (COVID-19) is challenging global public health response system. We aim to identify the risk factors for the transmission of COVID-19 using data on mainland China. We estimated attack rate (AR) at county level. Logistic regression was used to explore the role of transportation in the nationwide spread. Generalized additive model and stratified linear mixed-effects model were developed to identify the effects of multiple meteorological factors on local transmission. The ARs in affected counties ranged from 0.6 to 9750.4 per million persons, with a median of 8.8. The counties being intersected by railways, freeways, national highways or having airports had significantly higher risk for COVID-19 with adjusted odds ratios (ORs) of 1.40 (p = 0.001), 2.07 (p < 0.001), 1.31 (p = 0.04), and 1.70 (p < 0.001), respectively. The higher AR of COVID-19 was significantly associated with lower average temperature, moderate cumulative precipitation and higher wind speed. Significant pairwise interactions were found among above three meteorological factors with higher risk of COVID-19 under low temperature and moderate precipitation. Warm areas can also be in higher risk of the disease with the increasing wind speed. In conclusion, transportation and meteorological factors may play important roles in the transmission of COVID-19 in mainland China, and could be integrated in consideration by public health alarm systems to better prevent the disease.

Psychological impact of COVID-19 on medical care workers in China.

BACKGROUND: Medical care workers experienced unprecedented levels of workload and pressure since the outbreak of coronavirus disease 2019 (COVID-19). Little is known about its exact impact on medical care workers and related factors in China. This study aims to identify the psychological impact of COVID-19 on medical care workers in China. METHODS: From February 23 to March 5, 2020, a cross-sectional survey was conducted among 863 medical care workers from seven provinces in China using standard questionnaires measuring adverse psychological outcomes including Impact of Event Scale-6 (IES-6), Depression, Anxiety and Stress Scale(DASS)and related psychosocial factors like perceived threat, social support and coping strategies. Exploratory Factor analysis was performed to identify the dimensions of perceived threat by study participants. Multivariate regression was used to examine the determinants of adverse psychological outcomes. RESULTS: Posttraumatic stress (PTS) were prevalent in this sample of health care professionals, and 40.2% indicated positive screens for significant posttraumatic stress disorder symptoms. The proportion of having mild to extremely severe symptoms of depression, anxiety and stress were 13.6, 13.9 and 8.6%, respectively. Perceived threat and passive coping strategies were positively correlated to PTS and DASS scores, while perceived social support and active coping strategies were negatively correlated to DASS scores. Nurses were more likely to be anxious than others among medical care workers during the COVID-19 epidemic. CONCLUSIONS: Adverse psychological symptoms were prevalent among medical care workers in China during the COVID-19 epidemic. Screening for adverse psychological outcomes and developing corresponding preventive measures would be beneficial in decreasing negative psychological outcomes.

Age-dependent Gender Differences in COVID-19 in Mainland China: Comparative Study.

BACKGROUND: The ongoing pandemic of novel coronavirus disease 2019 (COVID-19) is challenging the global public health system. Sex differences in infectious diseases are a common but neglected problem. METHODS: We used the national surveillance database of COVID-19 in mainland China to compare gender differences in attack rate (AR), proportion of severe and critical cases (PSCC), and case fatality rate (CFR) in relation to age, affected province, and onset-to-diagnosis interval. RESULTS: The overall AR was significantly higher in females than in males (63.9 vs 60.5 per 1 million persons; P ˂ .001). In contrast, PSCC and CFR were significantly lower among females (16.9% and 4.0%) than among males (19.5% and 7.2%), with odds ratios of 0.87 and 0.57, respectively (both P ˂ .001). The female-to-male differences were age dependent, and were significant among people aged 50-69 years for AR and in patients aged 30 years or older for both PSCC and CFR (all P ≤ .001). The AR, PSCC, and CFR varied greatly from province to province. However, female-to-male differences in AR, PSCC, and CFR were significant in the epicenter, Hubei province, where 82.2% confirmed cases and 97.4% deaths occurred. After adjusting for age, affected province, and onset-to-diagnosis interval, the female-to-male difference in AR, PSCC, and CFR remained significant in multivariate logistic regression analyses. CONCLUSIONS: We elucidate an age-dependent gender dimorphism for COVID-19, in which females have higher susceptibility but lower severity and fatality. Further epidemiological and biological investigations are required to better understand the sex-specific differences for effective interventions.