OBJECTIVE: To investigate the prevalence of Anisakis infections in coastal marine fishes and awareness of anisakiasis control knowledge among local residents in Yantai City, Shandong Province in 2021, so as to provide insights into formulation of anisakiasis control interventions.
METHODS: Marine fishes were purchased from Shunxin Port, Yantai City, Shandong Province in November 2021, and the presence of Anisakis was detected in different species of fishes and different fish sites. The correlations between body length and weight of marine fish and intensity of Anisakis infections were examined using Spearman\'s rank correlation analysis, and the dietary habits and anisakiasis control knowledge were investigated using questionnaire surveys among local residents.
RESULTS: A total of 201 marine fishes belonging to 20 species were dissected, and Anisakis was detected in 77 marine fishes (38.31%) belonging to 11 species (55.00%), with a mean infection intensity of 45.04 parasites per fish (3 468/77). Spearman\'s rank correlation analysis revealed that the body length (rs = 0.74, P < 0.05) and weight (rs = 0.79, P < 0.01) of the monkfish correlated positively with the intensity of Anisakis infections, and the body length (rs = 0.68, P < 0.05) of the flatfish correlated positively with the intensity of Anisakis infections, while no correlations were examined between the body length or weight of other marine fishes and the intensity of Anisakis infections. Of all respondents, 53.38% men and 56.67% women did not know anisakiasis control knowledge at all, and there was a significant difference in the proportion of respondents using separate chopping boards for raw and cooked food from different villages (χ2 = 17.89, P < 0.01), while there was an age-specific proportion of respondents with habitats of eating raw or semi-raw seafood (χ2 = 28.27, P < 0.01).
CONCLUSIONS: The prevalence and intensity of Anisakis infections were high in coastal marine fishes in Yantai City in 2021, and the awareness of anisakiasis control knowledge was low among local residents. Intensified health education pertaining to anisakiasis control knowledge is recommended to reduce the risk of Anisakis infections.
［摘要］ 目的 了解2021年山东省烟台市近海海鱼异尖线虫感染率和当地居民异尖线虫病相关知识知晓情况, 为制定 异尖线虫病防控措施提供参考依据。方法 2021年11月, 于山东省烟台市顺鑫港口购买海鱼, 检测海鱼异尖线虫感染 情况, 并分析不同鱼种、不同部位异尖线虫感染率。采用Spearman秩相关分析海鱼体长和体质量与异尖线虫感染度间 的相关性, 对当地居民饮食习惯和异尖线虫病防治知识知晓率进行问卷调查。结果 共解剖海鱼20种201尾, 其中11 种77尾检出异尖线虫, 鱼种异尖线虫感染检出率为55.00% (11/20)、海鱼总感染率为38.31% (77/201); 异尖线虫感染阳 性海鱼中累计检出异尖线虫3 468条, 平均感染度为45.04条/尾。Spearman秩相关结果显示, 鮟鱇鱼体长 (rs = 0.74, P < 0.05) 和体质量 (rs = 0.79, P < 0.01) 与异尖线虫感染度呈正相关, 比目鱼体长与感染度呈正相关 (rs = 0.68, P < 0.05), 其他 种类海鱼体长、体质量与异尖线虫感染度均无相关性。问卷调查结果显示, 53.38%男性和56.57%女性对异尖线虫病防 治知识完全不了解, 不同行政村居民生熟菜板不分比例差异有统计学意义 (χ2 = 17.89, P < 0.01), 不同年龄组居民有生食 或半生食海产品习惯者比例差异有统计学意义 (χ2 = 28.27, P < 0.01)。结论 2021年烟台市近海海域海鱼异尖线虫感染 率、感染度均较高, 当地居民异尖线虫病防治知识知晓率较低; 应加大对居民异尖线虫病健康教育, 降低异尖线虫感染 风险。.

Protecting and constructing urban ecological infrastructure (UEI) is an important spatial means of improving the quality of life of urban residents, enhancing the benefits of the urban environment, and improving urban habitats. Landscape connectivity is the basis for UEI to play an ecological role. Spatial equity is an important goal for UEI to enhance urban resident happiness and sense of access and achieve environmental justice. Taking Yantai city as an example, this study analyzed the UEI morphological spatial pattern based on morphological spatial pattern analysis and calculated the spatial accessibility of UEI based on the gravity -based two-step-floating catchment area (G2SFCA) method. In addition, the study proposed the concept of accessible UEI and reflected the spatial differences in the equity of accessible UEI in urban residential areas through equity modeling that was oriented to connectivity enhancement and equity improvement. Moreover, the study integrated the location-allocation model and circuit theory to optimize the spatial layout of the existing UEI and construct an urban ecological corridor that considered landscape connectivity and leisure and recreational convenience. The results of this study showed that the proportion of bridge and island areas with connecting functions in the existing UEI in Yantai was only 10%, and they had not yet formed a complete network structure; hence, connectivity improvements were needed. In addition, the equity of accessible UEI in the residential areas of Yantai was generally good, and more than two-thirds of residents had sufficient access to UEI. However, approximately 32.7% of the residents in the four old city areas lacked a UEI distribution within their effective commuting time. Moreover, UEI layout optimization could improve the equity of accessible UEI in residential areas; however, the method of adding a new UEI was not applicable to areas with high concentrations of urban populations and stable urban spatial layouts. Furthermore, urban ecological corridors could effectively improve the connectivity and equity of UEI; however, 70% relied on existing road systems and needed to enhance their ecological attributes. The UEI equity of residential areas was highly correlated with house prices, indicating an obvious spatial injustice in the UEI layout in Yantai. Planners and governments should promote urban environmental justice through effective conservation and construction measures by incorporating established ecological and artificial infrastructures into UEI planning to achieve equitable access to UEI services for urban residents. This study provides a spatial reference and methodological support to enhance the equity and connectivity of UEI.

Analysis of the pathogenic spectrum, epidemiological characteristics and molecular epidemiological features of important pathogens of infectious diarrhea in Yantai City, Shandong Province, 2018-2019, were analyzed to provide a reference basis for the prevention and control of infectious diarrhea.
A total of 1514 stool specimens were collected within 3 days of the onset of diarrhea in secondary or higher hospitals in Yantai from 2018-2019, and all specimens were tested for the presence of seven major viruses and three major bacteria by employing reverse transcription ploymeraer chain reaction (RT-PCR). Population and seasonal analyses were also performed on positive samples for infectious diarrhea. The top two ranked rotavirus and norovirus were focused on genotyping and analysis of geographical distribution.
The study showed that the high prevalence of infectious diarrhea in Yantai, Shandong Province, for two consecutive years in 2018 and 2019 was in young children aged 1-5 years, accounting for 48.6% of the total number of cases. Viral diarrhea was distributed throughout the year with no obvious seasonal distribution, while bacterial diarrhea was predominant in summer. Of 1514 stool specimens, the total positive rate of specimens was 43.92% (665/1514). One pathogen was detected in 507 specimens, two pathogens in 107 specimens, and three pathogens in 44 specimens, with mixed infections accounting for 22.71% of positive specimens (151/665). Viral diarrheal pathogens accounted for 93.23% (620/665) of positive samples. The percentages of positive samples for Rotavirus (RV), Norovirus GI, Norovirus GII, Enterovirus universal (EV), Enteroadenovirus (EAdV), Sapovirus (SaV), Astrovirus (Astv), Salmonella (SE), Listeria monocytogenes (LiMo), and Vibrio parahaemolyticus (VP) were 48.57%, 3.61%, 15.34%, and 10.68% of the total positive samples.
This study analyzed in detail the composition of infectious diarrhea pathogen spectrum, pathogen alternation pattern, seasonal distribution and population distribution of pathogens in Yantai City, Shandong Province, 2018-2019, to provide a basis for improving relevant local preventive measures and reducing the disease burden.

PM2.5 samples were collected at three sites in Yantai City during all four seasons of 2016-2017, and the mass concentration and chemical composition characteristics were analyzed. The CMB model was used to calculate source apportionment of ambient PM2.5, and the backward trajectory cluster and PSCF were used to analyze the transport flow and potential source regions. The results showed that the average mass concentrations of PM2.5 in winter, spring, summer, and autumn in Yantai were (89.45±56.80), (76.78±28.44), (32.65±17.92) and (57.32±24.60) μg·m-3, respectively. The PM2.5 concentration showed a significant seasonal variation (P<0.01). The contribution of PM2.5 sources was as follows:secondary nitrate (20.3%) > crustal dust (15.7%) > vehicle exhaust (14.9%) > coal combustion (13.8%) > secondary sulphate (12.8%) > SOC (6.1%) > cement dust (5.5%) > sea salt source (2.9%). It can be seen that the predominant sources were secondary sources, crustal dust, vehicle exhaust, and coal combustion. The sources of nitrate in spring and of crustal dust were important contributors. The contribution of sulfate in summer was prominent, and the proportion of coal combustion was high in autumn and winter. Yantai City\'s airflow transport and potential source regions also showed significant seasonal changes:winters were mainly affected by short-distance transport in Yantai City; summers were mainly affected by the coastal of eastern Yantai City and local areas; springs and autumns were mainly affected by regional transmission in the northeast and in the eastern coastal areas of Shandong Province and by local sources in Yantai City.