ABSTRACT
Since the SARS-CoV-2 virus outbreak has been recognized as a pandemic on March 11, 2020, several models have been proposed to forecast its evolution following the governments interventions. In particular, the need for fine-grained predictions, based on real-time and fluctuating data, has highlighted the limitations of traditional SEIR models and parameter fitting, encouraging the study of new models for greater accuracy. In this paper we propose a novel approach to epidemiological parameter fitting and epidemic forecasting, based on an extended version of the SEIR compartmental model and on an auto-differentiation technique for partially observable ODEs (Ordinary Differential Equations). The results on publicly available data show that the proposed model is able to fit the daily cases curve with greater accuracy, obtaining also a lower forecast error. Furthermore, the forecast accuracy allows to predict the peak with an error margin of less than one week, up to 50 days before the peak happens.
ABSTRACT
BACKGROUND: The causes of birth defects (BDs) are complex and include genetic and environmental factors and/or their interactions. More research is needed to describe the epidemiology of BDs within specific regions of China. This study focused on differences in the prevalence of BDs based on ethnicity in a large city in Guangxi Province, China. METHODS: Surveillance data of infants born in 114 registered hospitals in Liuzhou between 2011 and 2015 were analyzed to determine the epidemiology of BDs across five major ethnic groups. We calculated the prevalence of BDs and relative risk of BDs by ethnicity. RESULTS: There were 260,722 perinatal infants of which 6581 had BDs, with the average prevalence of 25.24 per 1000 perinatal infants (PIs). Prevalence data showed an obvious uptrend over the past 5 years. Han had the highest prevalence of total BDs (28.98), followed by Zhuang (25.19), Yao (18.50), Miao (15.78) and Dong (14.24). Relative to the Han; Zhuang, Miao, Yao, and Dong had a lower risk of musculoskeletal and urogenital malformations; Miao and Yao had a lower risk of cardiovascular malformation; and Dong had a lower risk of cardiovascular and craniofacial malformation. Several maternal risk factors were found to be associated with BDs (e.g., maternal and gestational age, number of antenatal care visits). CONCLUSION: This study provided a comprehensive description of ethnic differences in the risk of BDs in Liuzhou City, China. Observed ethnic differences in the risk of BDs may be related to genetic susceptibilities, environment, cultural customs, or to potential combinations of these factors.
