BACKGROUND: Human fishing activities have significantly affect environmental concern for marine ecosystems, conservation of marine mammals, and human health. Coastal cetaceans are highly vulnerable to ingestion of fishing gear, bycatching, or entanglement, all of which can be fatal for these animals. In particular, certain coastal dolphins and porpoises are heavily impacted by fishing gear such as angling gear or stownet, as their food often overlap with the target fish species of human fisheries.
METHODS: This study presents a case of an Indo-Pacific finless porpoise (Neophocaena phocaenoides) beached on the coast of Jeju Island, Republic of Korea, with ingestion of fishing gear and severe Anisakis infection. Although this species inhabits waters ranging from the Persian Gulf to Taiwan, several stranded carcasses have been reported on Jeju Island in recent years. Post-mortem computed tomography revealed a bundle of four fishing hooks in the forestomach, along with nylon lines and steel lines with connectors, which were assumed to be angling gear for Jeju hairtail (Trichiurus lepturus). Further necroscopic investigation revealed that the forestomach contained a large number of Anisakis spp. (Nematoda: Anisakidae). Histological examination revealed a thickened forestomach wall with pinpoint and volcanic ulcerations, a thickened layer of stratified squamous epithelium, and infiltrated stroma in the squamous epithelium.
CONCLUSIONS: This study emphasizes the urgent need to address the impact of fishing activities on marine mammals, marine litter pollution, and the bycatch problem in Korean seawater. In addition, the occurrence of N. phocaenoides in seawater around Jeju Island should be raised in future geographical ecology or veterinary pathology studies and when its distribution is updated.

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。.

OBJECTIVE: To investigate the prevalence of Anisakis infection in marine fishes in Eastern Fujian Fishing Ground of Fujian Province, so as to provide insights into the development of the anisakiasis control strategy.
METHODS: Marine fish samples were randomly collected from Jiaocheng District, Fuding City and Xiapu County around Eastern Fujian Fishing Ground in Fujian Province from September to December, 2021. All fishes were dissected, and the abdominal contents were collected. Parasites were sampled under a stereomicroscope and the Anisakis species were identified through morphology. The prevalence and intensity of Anisakis infections were calculated.
RESULTS: A total of 177 marine fishes belonging to 24 species were dissected, and Anisakis was detected in 73 marine fishes (41.2%) belonging to 16 species (66.7%), with a mean infection intensity of 14.3 parasites per fish. High prevalence of Anisakis infection was found in Ilisha elongata (5/5), Miichthys miiuy (3/3), Plectorhynchus cinctus (2/2), Scomberomorus niphonius (12/13), Trichiurus lepturus (19/23), Pennahia argentata (6/11) and Ditrema temmincki (14/27), with mean infection intensities of 9.2, 2.7, 4.5, 10.9, 39.2, 4.5 parasites per fish and 2.1 parasites per fish. The Anisakis larvae were characterized as Anisakis and Hysterothylacium.
CONCLUSIONS: High prevalence of Anisakis infection is detected in marine fishes in Eastern Fujian Fishing Ground of Fujian Province. The health education pertaining to food health is required to be reinforced to prevent the development of human anisakiasis.
［摘要］ 目的了解福建省闽东渔场海洋鱼类异尖线虫感染情况, 为制定异尖线虫病控制策略、保障食品安全提供依 据。方法2021年9—12月在福建省闽东渔场沿海蕉城区、福鼎市、霞浦县随机收集海鱼样本, 解剖获取鱼腹腔内容物, 在体视显微镜下挑取寄生虫, 并在镜下根据异尖线虫形态特征鉴定虫种, 计算异尖线虫感染率和感染度。结果共解剖 海鱼24种177尾, 其中16种73尾海鱼检出异尖线虫, 鱼种检出率为66.7%、海鱼总感染率为41.2% ;感染度为1 ~ 148 条/尾, 平均感染度为14.3条/尾。异尖线虫感染率较高的鱼种为鳓鱼(5/5)、輓鱼(3/3)、包公鱼(2/2)、马鲛鱼(12/13)、带 鱼(19/23)、白姑鱼(6/11)、海鲫鱼(14/27), 平均感染度依次为9.2、2.7、4.5、10.9、39.2、4.5、2.1条/尾。检出的异尖线虫幼虫 经鉴定为异尖线虫属和宫脂线虫属。结论福建省闽东渔场海洋鱼类异尖线虫感染率较高, 应加强饮食健康宣传, 防止 人群异尖线虫病发生。.

OBJECTIVE: To investigate the prevalence of parasitic infections in freshwater fish and marine fish from markets in Zhenjiang City, so as to provide the evidene for formulating targeted control measures.
METHODS: Freshwater fish and marine fish were collected from farmers\' markets and supermarkets in Zhenjiang City using a random sampling method. The metacercaria and larvae of parasites were detected using microscopy and the direct dissection method. The prevalence of parasitic infections was analyzed in freshwater fish and marine fish.
RESULTS: The overall prevalence of parasite infections was 11.21% (208/1 856) in the 1 856 fish (34 species) detected from 2017 to 2020, and the prevalence was 9.81% (117/1 193) in freshwater fish and 13.73% (91/663) in marine fish. Among the 1 193 freshwater fish (23 species), high prevalence of parasitic infections was detected in Gambusia affinis (43.33%), coarse fish (32.93%) and Hemiculter leucisclus (20.20%), and there was no significant difference in the prevalence of parasitic infections among different species of freshwater fish (χ2 = 105.66, P < 0.05). Clonorchis sinensis, Metorchis orientalis and other parasite species were detected in freshwater fish, with detection rates of 0.59% (7/1 193), 1.93% (23/1 193) and 7.29% (87/1 193), respectively, and there was a significant difference in the detection of C. sinensis and M. orientalis in freshwater fish (χ2 = 8.64, P < 0.05). The prevalence and intensity of larval Anisakis infections were 13.73% (91/663) in marine fish and 3.43 parasites per fish. High prevalence of Anisakis infections was seen in little yellow croaker fish (30.28%) and hairtail (27.50%), and there was a significant difference in the prevalence of parasitic infections in different species of marine fish (χ2 = 12.93, P < 0.05).
CONCLUSIONS: Parasitic infections are prevalent in freshwater fish and marine fish from markets of Zhenjiang City, and there is a risk of parasitic infections following consumption of raw or under-cooked freshwater fish and marine fish.
［摘要］ 目的了解镇江市市售淡水鱼和海鱼中寄生虫感染情况, 为制定有针对性的防治措施提供参考依据。 方法 2017—2020年采用随机抽样调査方法, 采集镇江市部分农贸市场和超市淡水鱼和海鱼, 分别采用压片镜检法和直接解剖法检测寄生虫囊呦和幼虫, 统计不同鱼种寄生虫感染情况。结果 2017—2020年累计检测34种、1 856尾海 鱼, 寄生虫感染率为11.21%(208/1 856), 其中淡水鱼感染率为9.81%(117/1 193)、海鱼感染率为13.73%(91/663)。共 检测淡水鱼23种1 193尾, 柳条鱼(43.33%)、小杂鱼(32.93%)和餐条鱼(20.20%)寄生虫感染率较高, 各淡水鱼鱼种寄生 虫感染率差异有统计学意义(χ2 = 105.66, P <0.05)。淡水鱼中检出的寄生虫有华支睾吸虫、东方次睾吸虫和其他类寄生 虫, 检出率分别为0.59%(7/1 193)、1.93%(23/1 193)和7.29%(87/1 193), 华支睾吸虫与东方次睾吸虫检出率差异有统计 学意义(χ2= 8.64, P < 0.05)。共检测海鱼11种663尾, 异尖线虫幼虫检出率为13.73%(91/663), 其中感染率较高的鱼种 为小黄鱼(30.28%)和带鱼(27.50%), 感染度为3.43条/尾, 各种海鱼寄生虫感染率差异有统计学意义(χ2 = 12.93, P < 0.05)。结论 镇江市市售淡水鱼和海鱼中存在寄生虫感染, 人群生食或半生食有寄生虫感染的风险。.

Studying the genetic diversity of nematode parasite populations is crucial to gaining insight into parasite infection dynamics and informing parasite phylogeography. Anisakiasis is a zoonotic disease caused by the consumption of infectious third-stage larvae (L3) of Anisakis spp. carried by marine fish. In the present study, a total of 206 mitochondrial DNA sequences (cytochrome c oxidase 2, cox2) were used to study the genetic diversity, genetic structure, and historical demography of twelve A. pegreffii populations from Trichiurus japonicas along the coast of mainland China and Taiwan. Two distinct evolutionary lineages of A. pegreffii and no significant genealogical structures corresponding to sampling localities suggested that isolation in the marginal seas shaped their patterns of phylogeographic distribution along the coast of mainland China and Taiwan during glaciation with lower sea levels. Furthermore, pairwise FST values and AMOVA did not indicate any significant genetic differentiation among groups with no relation to the geographic area, which might be attributed to fewer barriers to gene flow as well as large population sizes. The results of the neutrality test, mismatch distribution, and Bayesian skyline plot analyses showed that entire population underwent population expansion during the late Pleistocene. Analysis of the demographic history revealed that A. pegreffii underwent historical lineage diversification and admixture due to secondary contact based on ABC analysis. The present research represents the first definitive population structure and demographic history across sampling locations of A. pegreffii along the coast of mainland China and Taiwan.

Fish-borne parasites have been part of the global landscape of food-borne zoonotic diseases for many decades and are often endemic in certain regions of the world. The past 20 years or so have seen the expansion of the range of fish-borne parasitic zoonoses to new geographic regions leading to a substantial public health burden. In this article, we summarize current knowledge about the biology, epidemiology, clinical characteristics, diagnosis, treatment and control of selected fish-borne helminthic diseases caused by parasitic roundworm (Anisakis), tapeworm (Dibothriocephalus), and fluke (Metagonimus). Humans acquire infection via consumption of raw or improperly cooked fish or fish products. The burden from these diseases is caused by morbidity rather than mortality. Infected patients may present with mild to severe gastrointestinal (eg, abdominal pain, diarrhea, and indigestion) or allergic manifestations. Patients are often admitted to the hospital or clinic with acute symptoms and no prior health problems and no travel history. Diagnosis is often established based on the detection of the diagnostic parasite stages (eg, eggs or tapeworm segments) in the patient\'s feces. Sometimes imaging is required to exclude other causes and avoid unnecessary surgery. Dibothriocephalus and Metagonimus are mainly treated with praziquantel. Extraction of adult Dibothriocephalus or Anisakis larvae from the bowel ensures complete elimination of the parasites and prevents a relapse of infection. The development and implementation of more efficient food safety and public health strategies to reduce the burden of zoonotic diseases attributable to fish-borne parasites is highly desirable.

OBJECTIVE: To understand the situation of Anisakis infection of in market-available marine fish in Dongtai City, so as to provide the evidence for the assessment of the risk of human Anisakis infections.
METHODS: Raw and fresh marine fish caught in the sea of Dongtai City for sale were collected in 2018. The fish were weighted and dissected for the identification of Anisakis, and the prevalence and intensity of Anisakis infections were calculated. In addition, the correlation between the weight of Anisakis-infected marine fish and the infection intensity of Anisakis was examined.
RESULTS: There were four species of marine fish infected with Anisakis, including Trichiurus haumela, Scomberomorus niphonius, Pneumatophorus japonicus and Larimichthys polyactis. Among the 149 fish samples, there were 78 with Anisakis infections, with a prevalence rate of 52.35%. The prevalence of Anisakis infection was 100.00% (28/28), 30.00% (9/30), 0 (0/30), 53.33% (16/30) and 80.65% (25/31) in T. haumela, S. niphonius, cuttle fish, P. japonicus and L. polyactis, respectively. A total of 1 049 Anisakis worms were collected, and the overall intensity of infection was 13.45 worms per fish. Spearman correlation analysis showed a positive correlation between the weight of T. haumela and the intensity of Anisakis infection (rs = 0.38, P = 0.047), and no correlation was found in other fish species.
CONCLUSIONS: There is a high rate of Anisakis infection in marine fish along the offshore areas of Dongtai City. Intensification of health education is required and healthy and safe dietary habits are encouranged.
［摘要］ 目的 掌握东台市市售海鱼中异尖线虫感染现状, 为评估人群异尖线虫感染风险提供依据。方法 于2018年 采集东台市海域捕捞且在当地销售的未经加工的新鲜海鱼, 称重后解剖检测异尖线虫 (含包囊)。计算海鱼异尖线虫感 染率和感染度, 分析异尖线虫感染海鱼质量和异尖线虫感染度间的相关性。结果 采集的5种海鱼中有4种 (带鱼、马鲛 鱼、鲐鱼、小黄鱼) 检出异尖线虫。累计采集的149尾海鱼样本中, 78尾感染异尖线虫, 总感染率为52.35%, 带鱼、马鲛鱼、墨鱼、鲐鱼、小黄鱼感染率分别为100.00% (28/28)、30.00% (9/30)、0 (0/30)、53.33% (16/30)、80.65% (25/31)。共检出异尖 线虫1 049条, 总感染强度为13.45条/尾。Spearman秩相关检验显示, 带鱼质量与异尖线虫感染度成正相关 (rs = 0.38, P = 0.047) ; 其他鱼类质量和异尖线虫感染度无相关性。结论 东台市近海海域鱼类存在较高异尖线虫感染率, 应进一步加 大宣传教育力度, 倡导市民养成健康安全的饮食习惯。.

OBJECTIVE: To investigate the risk of Anisakis infections among high-risk populations along the coastal areas of Jiangsu Province, so as to develop the strategy for the prevention and control of anisakiasis in the province.
METHODS: Three counties along the coastal areas of Jiangsu Province were selected as the study sites in 2018, including Rudong County in Nantong City, Haizhou District in Lianyungang City and Dongtai City in Yancheng City. The knowledge, attitude and practice (KAP) of anisakiasis prevention and control, and the prevalence of serum specific IgG antibody against Anisakis were investigated among high-risk populations among these three study sites, including fishermen, fish seller and people who liked eating fresh and live marine fish. Factors affecting the prevalence of the specific IgG antibody against Anisakis were identified using a multiple logistic regression model. In addition, Anisakis larvae infections were detected in fresh and live marine fish samples collected from local markets, and the prevalence and intensity of Anisakis infections were estimated.
RESULTS: A total of 625 high-risk populations were investigated, including 349 men (55.8%). Only 13.0% of the subjects heard about anisakiasis, and a low awareness rate of anisakiasis prevention and control knowledge was seen among these three types of high-risk populations. There were 21.6% of the subjects eating raw or half-cooked marine fish, 5.8% eating undercooked marine fish, 3.2% presenting vomiting, nausea and diarrhea after eating marine fish, 5.1% developing systemic allergic symptoms, and 65.6% using the same chopping board for raw and cooked food. The sero-prevalence of the anti-Anisakis IgG antibody was 7.0% among the study subjects. Multiple logistic regression analysis identified education level [OR = 0.687, 95% CI (0.478, 0.987)] and development of systemic allergic symptoms [OR = 4.641, 95% CI(1.411, 15.268)]as factors affecting the positive anti-Anisakis IgG antibody among the study subjects. Among 494 fresh and live marine fish detected, the prevalence and intensity of Anisakis larvae infection was 64.0% and 8.1 larvae per fish, with high prevalence seen in Trichiurus haumela and Pneumatophorus japonicas.
CONCLUSIONS: The awareness of anisakiasis prevention and control knowledge is low among the high-risk populations living along the coastal areas of Jiangsu Province, and there are high-risk behaviors, such as eating raw or half-cooked food, using the same chopping board for raw and cooked food. In addition, the prevalence of Anisakis infections is high in the marine fish in these areas. Therefore, the health education and health promotion for anisakiasis prevention and control should be intensified.
［摘要］ 目的 了解江苏省沿海地区高危人群异尖线虫感染风险, 为制定江苏省异尖线虫病预防控制措施提供基础数据。方法 2018 年选择江苏省沿海地区南通市如东县、连云港市海州区和盐城市东台市作为调查点, 对从事海鱼捕捞、鲜活海鱼销售、喜食鲜活海鱼者等 3 类异尖线虫感染高危人群开展异尖线虫病防治知行信调查, 检测血清特异性异尖线虫IgG抗体, 并对上述人群血清IgG抗体阳性的影响因素进行logistic回归分析。采集当地鲜活海鱼样本, 检测异尖线虫幼虫感染情况, 计算感染率和感染度。结果 本次调查 3 类高危人群 625 人, 其中男性 349 人 (占55.8%)。问卷调查显示, 听说过异尖线虫病的有 81 人 (13.0%); 3 类人群对异尖线虫病防治知识知晓率普遍较低, 生食或半生食海鱼者占 21.6%, 5.8% 的调查对象选择吃未煮熟的海鱼; 3.2% 食用海鱼后出现恶心、呕吐、腹泻等症状; 5.1% 出现全身过敏症状, 65.6% 砧板切生熟食不分。血清学检测结果显示, 调查人群血清异尖线虫特异性IgG抗体阳性率为7.0%。Logistic回归分析显示, 受教育程度 [OR = 0.687, 95% CI (0.478, 0.987) ]和是否存在全身过敏症状 [OR = 4.641, 95% CI (1.411, 15.268) ]是调查人群血清学IgG抗体阳性的影响因素。累计调查海鱼 494 条, 异尖线虫幼虫感染率为 64.0%, 感染度为 8.1 条/鱼, 其中带鱼和青占鱼感染率较高。结论 江苏省沿海地区高危人群异尖线虫病防治知识知晓率较低, 且存在生食或半生食、砧板切生熟食不分等高危行为; 该地区海鱼异尖线虫感染率高。后续应进一步加强异尖线虫病健康教育和健康促进工作。.

The cinnamon flounder Pseudorhombus cinnamoneus is a frequently consumed marine fish in China. However, the occurrence of ascaridoid larvae in P. cinnamoneus remains unclear. In the present study, a total of 85 P. cinnamoneus caught from the Yellow Sea (off Shidao, 36°52\'57″N, 122°26\'42″E) in 2011, which is located between mainland China and the Korean Peninsula, was investigated for ascaridoid larval infection. Four ascaridoid larval types, including Anisakis type I of Berland (1961), Hysterothylacium type of Smith (1983), Hysterothylacium type HL of Guo et al. (2014) and Raphidascaris type of Zhao et al. (2016), were detected in this important food fish. These larval types were identified as Anisakis pegreffii, Hysterothylacium aduncum, H. sinense and Raphidascaris lophii, respectively, using PCR-based restriction fragment length polymorphism (PCR-RFLP) analysis and sequencing of the ITS region of nuclear ribosomal DNA (rDNA). The third-stage larvae of H. sinense are reported from Chinese waters for the first time. The prevalence of H. sinense was 100% and represents the predominant species of the ascaridoid larvae found in P. cinnamoneus. The prevalences of A. pegreffii and H. aduncum were 44.7% and 81.2%, respectively. Phylogenetic analyses based on ITS sequences were performed to elucidate the genetic relationships of these ascaridoid nematodes. The present study increases the knowledge and distribution of ascaridoid larvae in this area of Yellow Sea. The high prevalence of ascaridoid larvae in P. cinnamoneus shows that an assessment needs to be undertaken to assess the risk these parasites may pose to public health.

Marine fishes represent the important components of the diet in the coastal areas of China and they are also natural hosts of various parasites. However, to date, little is known about the occurrence of ascaridoid parasites in the frequently consumed marine fishes in China. In order to determine the presence of ascaridoid parasites in the frequently consumed marine fishes in the coastal town Huizhou, Guangdong Province, China, 211 fish representing 45 species caught from the South China Sea (off Daya Gulf) were examined. Five species of ascaridoid nematodes at different developmental stages were detected in the marine fishes examined herein, including third-stage larva of Anisakis typica (Diesing, 1860), third and fourth-stage larvae of Hysterothylacium sp. IV-A of Shamsi, Gasser & Beveridge, 2013, adult and third-stage larvae of Hysterothylacium zhoushanense Li, Liu & Zhang, 2014, adults and third-stage larvae of Raphidascaris lophii (Wu, 1949) and adults of Raphidascaris longispicula Li, Liu & Zhang, 2012. The overall prevalence of infection is 18.0%. Of them, Hysterothylacium sp. IV-A with the highest prevalence (17.5%) and intensity (mean=14.6) of infection was the predominant species. The prevalence and intensity of A. typica were very low (1/211 of marine fish infected with an intensity of one parasite per fish). The morphological and molecular characterization of all nematode species was provided. A cladistic analysis based on ITS sequence was constructed in order to determine the phylogenetic relationships of these ascaridoid parasites obtained herein. The present study provided important information on the occurrence and diagnosis of ascaridoid nematodes in the commercially important marine fishes from the South China Sea. The low level of infection and the species composition of ascaridoid nematodes seem to indicate the presence of low risk of human anisakidosis when local population consumed these marine fishes examined herein.