A COVID-19 Outbreak Emerging in a Food Processing Company - Harbin City, Heilongjiang Province, China, January-February 2021.

What is already known about this topic? The coronavirus disease 2019 (COVID-19) epidemic in China had been effectively controlled for several months, but as the ambient temperature dropped, large gathering-initiated epidemics occurred in northern China, including Hebei, Liaoning, and Jilin provinces. What is added by this report? A sudden epidemic emerged in Wangkui County, Suihua City, Heilongjiang Province, on January 9, 2021. An asymptomatically-infected resident of Harbin City returned from Suihua and triggered a large-scale outbreak in the Zhengda Food Processing Company in Harbin, Heilongjiang. The epidemic was associated with widespread community transmission inside and outside the company, eventually leading to 260 persons being infected (87.8% of 296 patients in Harbin). What are the implications for public health practice? This study demonstrates the importance of screening for infections in the COVID-19 prevention and control system, shares experiences identifying and managing asymptomatic infections, and recommends food processing enterprises like the Zhengda Company to improve preventative measures. Our evidence-based epidemiological analyses provide methods for finding high-risk settings and evaluating epidemic situations when many asymptomatic patients are identified in a short period of time.

A Spatial Ecology Study of Keshan Disease and Hair Selenium.

Few spatial ecological studies on hair selenium (Se) and Keshan disease (KD) have been reported. To investigate the relationships of hair Se with KD and economic indicators and to visualize the evidence for KD precise prevention. An ecological study design was employed. The levels of hair Se of 636 adult men (≥ 18 years old) living in rural, general cities and developed cities in 15 KD endemic provinces and 11 KD non-endemic provinces in mainland China were measured using hydride generation atomic fluorescence spectrometry. Spatial description and spatial analysis of hair Se were conducted. The subjects were adults aged. The hair Se level of the residents of KD endemic areas was 0.30 mg/kg, statistically significantly lower than that of non-endemic areas 0.34 mg/kg (Mann-Whitney U test, p = 0.007). The hair Se level of the 636 people was 0.33 mg/kg. The hair Se levels of the residents of the developed cities, general cities, and rural were 0.35 mg/kg, 0.33 mg/kg, and 0.32 mg/kg, respectively, with statistical significance (Kruskal-Wallis H test, P = 0.032). Spatial regression analysis showed that the spatial distribution of hair Se was positively correlated with per capita GDP. Selenium deficiency may still exist among residents living in the KD endemic areas. The results of spatial description and analysis of hair Se provided visualized evidence for targeting key provinces for precise prevention of Keshan disease, including assessment of KD elimination. The hair Se level of the mainland Chinese males was probably between 0.31 and 0.33 µg/g in 2015.

A spatial ecological study of selenoprotein P and Keshan disease.

Few spatial ecological studies on selenoprotein P (SePP) and Keshan disease (KD) have been reported. The main objective of this study is to investigate the relationships of SePP with KD, economic indicators and soil selenium and to visualize the evidence for KD precise prevention and control. An ecological study design was employed. The serum SePP of 2351 subjects living in rural areas, general cities and developed cities in 15 KD endemic provinces and 13 KD non-endemic provinces in China were measured. Spatial description and spatial analysis of SePP were conducted. The subjects were adults aged. The mean serum SePP level of KD endemic area residents was 14.20 mg/L, significantly lower than that in non-endemic areas, 15.30 mg/L (t = - 3.19, P = 0.0010). Serum SePP levels were low among the people in the KD endemic provinces of Shandong, Inner Mongolia, Heilongjiang, etc. The mean serum SePP level of the 2351 people was 15.04 (95% CI: 14.76 and 15.31) mg/L. The mean serum SePP levels of residents in developed cities, general cities and rural areas were 16.54 mg/L, 14.98 mg/L and 14.44 mg/L, respectively, and were significantly different (F = 17.00, P < 0.0010). Spatial regression analysis showed that the spatial distribution of SePP was positively correlated with per capita consumption expenditure and soil selenium. Selenium deficiency may still exist among residents living in the KD endemic provinces. Shandong, Inner Mongolia, and Heilongjiang should be the target provinces, visualized by spatial analysis, for KD precise prevention and control.

An approach to assessment of Keshan disease elimination at the township level.

BACKGROUND: The aim of this study was to pilot a method of a small-scale survey for the assessment of Keshan disease (KD) elimination at township level. METHODS: The prevalence of chronic KD was obtained by case-searching the whole population. The endemic village with the highest prevalence of chronic KD was selected as the key village for the survey of latent KD prevalence rate among permanent residents. The selenium levels in the head hair of individuals in the key village was measured. The professionals of the department of endemic disease control, the township and village doctors were surveyed by pre-designed questionnaire survey for KD interventions. RESULTS: We conducted this study in 2013. Yuanbao township had a population of 16 487 people and 14 862 permanent residents. There were no acute or subacute KD cases in the previous 5 years. The prevalence rate of chronic KD and natural chronic KD were 6.7/10 000 and 3.4/10 000 respectively. The prevalence rate of latent KD was 250.6/10 000, higher than the elimination criterion. The head hair selenium levels were 0.23±0.18 mg/kg. CONCLUSIONS: The small-scale survey methodology for assessing KD elimination at township level was feasible. KD among the people living in Yuanbao township has not been eliminated.