麻痹性贝毒在广州市售经济贝类中污染状况分析

目的通过对广州市黄沙海产品批发市场7种经济贝类为期一年的麻痹性贝毒(PSP)污染状况的调查分析,了解海产品食用的安全性。方法毒性测定按照AOAC小白鼠法进行,成份分析利用高效液相色谱(HPLC),安全性评价采用联合国粮农组织(FAO)及我国渔政渔港监督管理局制定的贝类安全食用标准(4MUg肉)。结果在调查的84份贝样中,染毒贝整体毒力(消化腺与肉的加权平均毒力)低于4MUg肉,毒素最高含量仅为184MUg肉,所有贝类均在安全食用范围之内。染毒贝类主要为栉孔扇贝(ChlamysMimachlamysnobilis)和嵌条扇贝(Pectenalbicans)。毒素在2个种9份样品的消化腺中检出,某些样品肌肉组织出现小白鼠毒性反应。一份样品消化腺中毒素含量高达1452MUg,高效液相色谱(HPLC)分析表明,该样品毒素成份主要为B1、GTX23、GTX14及C类。结论广州市市售鲜贝PSP含量和检出率整体水平均较低;贝中消化腺毒素含量及检出率明显高于肌肉,个别腺体毒素含量超出标准。毒素分布存在季节性差异,春季毒素比较强,夏秋季检出率高。因此有针对性的加强贝毒监测非常必要。     

广州市售贝类麻痹性贝毒和腹泻性贝毒污染状况分析

目的对广州市售双壳经济贝类麻痹性贝毒(PSP)和腹泻性贝毒(DSP)污染状况进行为期一年的抽样调查,了解其食用安全性。方法采用AOAC推荐的小鼠生物检测法进行PSP和DSP的毒力测定,采用HPLC进行PSP成分分析,根据FAO、日本和欧盟水产食品卫生要求及我国渔政渔港监督管理局制订的贝类安全食用标准对贝类水产品的食用安全性进行评价。结果在所调查的7种贝类中,有2种染有PSP,毒素含量在安全食用范围内,毒力大小随季节而变化,春冬两季含量相对较高;7种贝类中有6种共计36个样品染有DSP,有10个样品毒素含量超出安全食用标准,春冬两季染毒率较高。结论广州市售贝类PSP含量和检出率整体水平较低;DSP检出率稍高,毒素含量也较高,应引起有关部门的关注,加强DSP监测工作。     

中国沿海的贝毒问题研究

我国对贝毒的调查研究工作目前正在开始，除了已查明江瑶具有内源性贝毒之外，主要的研究工作集中在赤潮产生的麻痹性贝毒（ＰＳＰ）上面，ＰＳＰ中毒案例主要发生在中国南方的浙江、福建、广东及台湾等地，其中有一些案例是致命性的。科研人员研究了广东省各种贝类中ＰＳＰ的含量，组织中分布及季节变化的情况，对其组份进行分析发现主要成份为ＳＴＸ，ｎｅｏＳＴＸ及ＧＴＸ１～４等。在我国沿海已发现了三种产生ＰＳＰ的毒藻，其中的Ａｌｅｘａｎｄｒｉｕｍｔａｍａｒｅｎｓｅ已分离出孢子并培养出单株克隆体供研究用，值得注意的是，我国沿海还发现过产生腹泻性贝毒，神经性贝毒及失忆性贝毒等毒源藻类，应提高警惕其形成“赤潮”，并在贝体内大量积累的可能性     

从暴发腹泻的贻贝中同时检出腹泻性贝类毒素和扇贝毒素

目的:2011年5月25日-5月27日,我市苍南县暴发了57例因食用贻贝引起的腹泻性贝类毒素(DSP)中毒事件,采集了19份样品进行检测。方法:采用超高效液相色谱-串联质谱方法对贻贝中5种脂溶性贝类毒素进行检测,根据欧盟贝类毒素的限量值进行评价。结果:15份样品检出大田软海绵酸(OA)、鳍藻毒素-1(DTX-1)和7-epi-pectenotoxin-2 seco acid(7-epi-PTX-2sa),16份检出pectenotoxin-2seco acid(PTX-2sa),7份检出pectenotoxin-2(PTX-2)。其中4份样品中游离OA和DTX-1含量超出欧盟限量值3倍多,它们的总OA约超出9倍。其余均低于欧盟限量值。首次在我国贝类中检出了PTX-2sa和7-epi-PTX-2sa。结论:鉴于部分贻贝样品DSP超标,今后应加强贝类上市前的监测工作。     

Cluster analysis of toxins profile pattern as a tool for tracing shellfish contaminated with PSP-toxins

Paralytic shellfish poisoning (PSP) is one of the most lethal biotoxin-induced diseases worldwide, which may pose serious public health threat and potential devastating economic damage on fisheries industry in the affected region(s). To prevent the importation of PSP contaminated shellfish to a community, detailed documentation on the supply chain and routine surveillance systems are, in principle, crucial measures to protect people from this intoxication. However, difficulties have always been encountered on the traceability of the source/origin of contaminated shellfish.In the present study, we reported the potential application of PSP-toxins profiles with similarity analysis that can be used to identify epidemiological linkage between shellfish samples collected from markets and patients during a PSP outbreak. PSP-toxins were identified and quantified by ion-pair chromatographic separation followed by post-column oxidation to fluorescent imino purine derivatives. Samples from a PSP incident and other surveillance samples collected in our past 7-year record were also compared for their similarity in PSP-toxins profiles patterns. Molar distributions (nmol%) of 10 PSP-toxins were analyzed by Unweighted Pair Group Method with Arithmetric averages (UPGMA). Three prominent clusters emerged with similarity levels reaching over 80% for each, suggesting that each group of samples probably originated from a same source/batch. The PSP-toxins profiles and toxicities determined from surveillance samples could provide premonitory clues on the occurrences of PSP incident and outbreak with corresponding toxin profiles in the later time. Due to species-specific characteristics of PSP-toxins composition and profile in shellfish under varieties of environmental and physiological conditions, PSP-toxins profile can be a specific and useful biochemical indicator for tracing PSP contaminated shellfish provided that spatio-temporal occurrence patterns of toxins profiles are available in a databank for inter-laboratory comparison and standardized methodologies such as consentaneous toxins extraction and identification criteria are used for analysis and comparison.     

Haemophilus influenzae Serotype a Invasive Disease,Alaska, USA, 1983–2011

Before introduction of Haemophilus influenzae type b (Hib) vaccines, rates of Hib disease in Alaska’s indigenous people were among the highest in the world. Vaccination reduced rates dramatically; however, invasive H. influenzae type a (Hia) disease has emerged. Cases of invasive disease were identified through Alaska statewide surveillance during1983–2011. Of 866 isolates analyzed for serotype, 32 (4%) were Hia. No Hia disease was identified before 2002; 32 cases occurred during 2002–2011 (p<0.001). Median age of case-patients was 0.7 years; 3 infants died. Incidence of Hia infection (2002–2011) among children <5 years was 5.4/100,000; 27 cases occurred in Alaska Native children (18/100,000) versus 2 cases in non-Native children (0.5/100,000) (risk ratio = 36, p<0.001). From 12/2009 to 12/2011, 15 cases of Hia disease occurred in southwestern Alaska (in children <5 years, rate = 204/100,000). Since introduction of the Hib conjugate vaccine, Hia infection has become a major invasive bacterial disease in Alaska Native children.     

Estimating the global burden of thalassogenic diseases: human infectious diseases caused by wastewater pollution of the marine environment

This paper presents a preliminary attempt at obtaining an order-of-magnitude estimate of the global burden of disease (GBD) of human infectious diseases associated with swimming/bathing in coastal waters polluted by wastewater, and eating raw or lightly steamed filter-feeding shellfish harvested from such waters. Such diseases will be termed thalassogenic--caused by the sea. Until recently these human health effects have been viewed primarily as local phenomena, not generally included in the world agenda of marine scientists dealing with global marine pollution problems. The massive global scale of the problem can be visualized when one considers that the wastewater and human body wastes of a significant portion of the world's population who reside along the coastline or in the vicinity of the sea are discharged daily, directly or indirectly, into the marine coastal waters, much of it with little or no treatment. Every cubic metre of raw domestic wastewater discharged into the sea can carry millions of infectious doses of pathogenic microorganisms. It is estimated that globally, foreign and local tourists together spend some 2 billion man-days annually at coastal recreational resorts and many are often exposed there to coastal waters polluted by wastewater. Annually some 800 million meals of potentially contaminated filter-feeding shellfish/bivalves and other sea foods, harvested in polluted waters are consumed, much of it raw or lightly steamed. A number of scientific studies have shown that swimmers swallow significant amounts of polluted seawater and can become ill with gastrointestinal and respiratory diseases from the pathogens they ingest. Based on risk assessments from the World Health Organization (WHO) and academic research sources the present study has made an estimate that globally, each year, there are in excess of 120 million cases of gastrointestinal disease and in excess of 50 million cases of more severe respiratory diseases caused by swimming and bathing in wastewater-polluted coastal waters. Filter-feeding shellfish/bivalves, which are often harvested from wastewater-polluted areas of the sea, can effectively filter out and concentrate the microbial pathogens in the seawater. It can be roughly estimated that annually there are some 4 million cases of infectious hepatitis A and E (HAV/HEV), with some 40 thousand deaths and 40 thousand cases of long-term disability, mainly chronic liver damage, from consuming raw or lightly steamed filter-feeding shellfish/molluscs harvested globally from polluted coastal waters. The total global health impact of the thalassogenic diseases--human infectious diseases associated with pathogenic microorganisms from land-based wastewater pollution of the seas--is estimated to be about 3 million 'disability-adjusted life years' (DALY)/year, with an estimated economic loss of some 12 billion dollars per year. Due to the preliminary nature of the estimates in this study it is appropriate to assume that all of the above figures are no more than first approximations and that the true figures may be 50% higher or lower. Nevertheless, it is the author's belief that this study indicates that wastewater pollution of the sea results in a multi-billion dollar per year health burden and that preventing wastewater pollution of the sea is worthy of inclusion on the global agenda of marine pollution prevention and control.     

一起赤潮后海产品麻痹性贝类毒素衰减结果分析

目的 以2017年漳州沿海一起赤潮引起的麻痹性贝类毒素(paralytic shellfish poisoning,PSP)中毒事件为研究起点,研究贝类海产品中的PSP在自然条件下的衰减情况。方法 在漳浦佛昙和龙海港尾海域采集牡蛎和贻贝进行PSP检测。结果 2017年6月8日相关海域海产品最大毒素总毒力为21 056.7 μg/kg,2017年6月26日海产品PSP总毒力值衰减86%以上,2017年7月20日海产品PSP总毒力值衰减97%以上,2018年12月所有海产品中PSP均未检出。结论 本次赤潮发生后,漳浦佛昙和龙海港尾两个海域贝类海产品约需45天净化周期方可食用,相关海域约需18个月净化至贝类毒素完全消失。     

ELISA快速测定带子中麻痹性贝类毒素含量

目的 分析测定导致中毒的带子及珠海市售的带子中麻痹性贝类毒素(PSP)含量.方法 依据SN/T1773-2006,采用美国Abraxiskits公司生产的SAXITOXIN (PSP) ELISA KIT (96T)试剂盒,测定食物中毒客户留样及市售的带子样品中麻痹性贝类毒素含量,并进行方法检出限、相对标准偏差(RSD)测定,以确保检测结果的有效性.结果 6份带子样品(1份食物中毒客户留样,5份市场抽检),其中5份检出麻痹性贝类毒素,含量为9.1～59.9 μg/kg.方法检出限为5.0 μg/kg、RSD为12.9％.结论 所检6份带子样品中有5份检出含有麻痹性贝类毒素(PSP).所检样品PSP的含量与流行病学调查较吻合.     

麻痹性贝类毒素细胞检测法的建立

目的:麻痹性贝类毒素的N-2a细胞检测方法的建立并确定可能的检测限值。方法:使用不同浓度毒素标准品结合藜芦定和乌本苷共同作用对数生长期的N-2a细胞,通过cck-8试剂盒检测细胞毒性,确立细胞检测方法的检出限及比较各毒素作用大小,并同步利用小鼠生物法进行验证,通过精确记录小鼠死亡时间,比较各毒素的毒作用大小。结果:麻痹性贝类毒素能明显降低藜芦定和乌本苷的细胞毒性,且具有剂量-反应关系,通过比较得出毒素各成分毒性大小为:neoSTX>STX>dcSTX>GTX1,4>GTX2,3>dcGTX2,3;小鼠生物法的毒作用平均死亡时间为:neoSTX组(6.5 min),GTX1,4组(8.0 min),STX组(9.0 min),dcSTX组(15 min);GTX2,3组和dcGTX2,3组未见动物死亡。结论:细胞检测与小鼠生物法具有较好的一致性,表明所建立的细胞检测法可行,且细胞毒性试验检测方法具有较高的灵敏度,最低检出限值可达到10-9mol/L剂量水平,其中浓度在10-6~10-8mol/L间具有较好的线性。     

A multistate outbreak of hepatitis A caused by the consumption of raw oysters.

BACKGROUND. In August 1988 we investigated a multistate outbreak of hepatitis A caused by Panama City, Florida, raw oysters. METHODS. Cases of hepatitis A (HA) with onset in July-August 1988 were identified among persons who ate seafoods harvested in the coastal waters of Panama City, Florida. We conducted a case-control study, using eating companions of case-patients, and calculated attack rate (AR) per 1000 dozen raw oysters served. Enzyme immunoassay (EIA) and a polymerase chain reaction (PCR) technique were performed on samples of raw shellfish obtained from Panama City coastal waters. RESULTS. Sixty-one case-patients were identified in five states: Alabama (23), Georgia (18), Florida (18), Tennessee (1), and Hawaii (1). We found an increased risk of HA for raw oyster eaters (odds ratio = 24.0; 95% confidence interval = 5.4-215.0; P less than .001). The AR of HA in seafood establishments was 1.9/1000 dozen raw oysters served. The EIA and PCR revealed HA virus antigen and nucleic acid in oysters from both unapproved and approved oyster beds, in confiscated illegally harvested oysters, and in scallops from an approved area. CONCLUSIONS. The monitoring of coastal waters and the enforcement of shellfish harvesting regulations were not adequate to protect raw oyster consumers. More emphasis should be placed on increasing public awareness of health hazards associated with eating raw shellfish.     

免疫亲和色谱分离纯化PSP贝毒GTX23,的研究

目的:分离纯化有毒塔玛亚历山大藻中麻痹性贝毒GTX2,3组分。方法:采用免疫亲和色谱方法,对有毒塔玛亚历山大藻中麻痹性贝类毒素进行分离纯化。结果:通过HPLC检测,免疫亲和柱有效的将麻痹性贝毒的GTX2,3与GTX14,分离,获得了一定数量但具有高纯度的麻痹性贝毒GTX23,。结论:初步建立了免疫亲和色谱技术对麻痹性贝类毒素GTX23,分离纯化的方法。     

Outbreak of botulism type E associated with eating a beached whale--Western Alaska,July 2002

Botulism is a neuroparalytic illness caused by toxins produced by the bacterium Clostridium botulinum, an obligate anaerobe found commonly in the environment. Intoxication with toxin type E is associated exclusively with eating animal foods of marine (salt or fresh water) origin. Persons who eat raw or fermented marine fish and mammals are at high risk for botulism from type E toxin. On July 17, 2002, the Alaska Division of Public Health investigated a cluster of suspected botulism cases among residents of a fishing village in Alaska. This report summarizes the findings of the outbreak investigation, which linked disease to eating raw muktuk (skin and a pink blubber layer) from a beached whale (Figure). To avoid delays in treatment, health-care providers evaluating patients suspected of having botulism should base treatment decisions on clinical findings. Public health authorities should be notified immediately about any suspected botulism case.     

青岛市市售贝类中多环芳烃与多氯联苯的含量水平、组成特征及居民健康影响风险评估

目的　通过分析青岛市贝类中多氯联苯（PCBs）和多环芳烃（PAHs）含量水平和组成特征,对本市市售贝类的居民食用健康进行初步评估。方法　全市采集200份贝类样品采用气相色谱-质谱法测定贝类中PCBs与PAHs的含量;利用其平均含量,并结合青岛市居民对贝类的平均食物消费量,计算贝类中PCBs和PAHs的接触风险和致癌风险指数,评估青岛市居民贝类中PCBs和PAHs的食用健康风险。结果　贝类中PCBs和PAHs的含量范围分别为未检出（ND）~168.66和ND~84.76μg/kg,中高氯联苯与中环芳烃在贝类中的比例较高;接触风险指数范围分别为0.191~0.399和1.12×10-5~1.44×10-4,皆小于1;总致癌风险指数范围为2.45×10-5~4.43×10-5,均在可接受致癌风险范围内。结论　青岛市居民对贝类水产品的食用健康风险较低,但PCBs各风险指数均高于PAHs,应加以重点关注。     

Investigating the Decline of Fetal and Infant Mortality Rates in Alaska During 2010 and 2011

Introduction The U.S. infant mortality rate has been steadily declining since 2007. Although the downward trend has been notable in Alaska since 2006 when the rate was 6.9 infant deaths per 1000 live births, a dramatic drop in infant mortality occurred in 2010 and 2011 when the infant mortality rate fell to 3.8 infant deaths per 1000 live births during both years. The purpose of this study was to investigate the sudden decrease in fetal and infant mortality rates (FIMR) using the perinatal periods of risk (PPOR) method, an approach that has not been used previously in Alaska. Methods The study was conducted for 251 fetal and infant deaths in 2004–2006, 265 deaths in 2007–2009, and 129 deaths in 2010–2011. Data were stratified by Alaska Native (AN) and White maternal race and urban/rural residence. Results Among both urban and rural White women, the rate ratios (RR) for FIMRs between the earlier and later time periods were not significantly different. The postneonatal mortality rate (PNMR) among AN infants living in rural areas decreased significantly (RR 0.40; 95 % confidence interval 0.21–0.76) between 2007–2009 and 2010–2011. An unexplained increase in sudden unexplained infant death was noted in 2009, followed by a precipitous decrease in 2010–2011. No other unusual distribution of the cause specific mortality rates was observed. Discussion The decrease in the Alaska Native FIMR might have been due to focused efforts for preventing postneonatal sleep associated deaths. Education for prevention of sleep related deaths, particularly in rural communities, is necessary to maintain Alaska’s low PNMR.     

Foodborne botulism in the United States, 1990-2000

Foodborne botulism, a potentially lethal neuroparalytic disease, is caused by ingesting preformed Clostridium botulinum neurotoxin. We reviewed surveillance data and reports from 1990 to 2000. Of 263 cases from 160 foodborne botulism events (episode of one or more related cases) in the United States, 103 (39%) cases and 58 events occurred in Alaska. Patients' median age was 48 years; 154 (59%) were female; the case-fatality rate was 4%. The median number of cases per event was 1 (range 1-17). Toxin type A caused 51% of all cases; toxin type E caused 90% of Alaska cases. A particular food was implicated in 126 (79%) events. In the lower 49 states, a noncommercial food item was implicated in 70 (91%) events, most commonly home-canned vegetables (44%). Two restaurant-associated outbreaks affected 25 persons. All Alaska cases were attributable to traditional Alaska Native foods. Botulism prevention efforts should be focused on those who preserve food at home, Alaska Natives, and restaurant workers.     

First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from S?o Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.     

宁波市有毒织纹螺地域分布分析

目的了解宁波市有毒织纹螺的分布。分析各栖息地有毒织纹螺的毒性变化，为控制织纹螺中毒提供依据。方法采用美国分析化学家学会（AOAC）和中国进出口检验检疫（CIQ）的小鼠生物测试法，以美国食品药物管理局（FDA）的贝类麻痹性毒素（PSP）标准，判定本地织纹螺毒性的强弱，按年观察结果。结果1986～2003年，宁波市127份被检织纹螺中毒素平均含量最高的年份为1991年，达11900MU／100g螺肉，最低年份为1988年，其毒素含量也达403MU／100gN肉，其他年份的毒性波动在一定范围内。不同栖息地毒螺检出率镇海区为31．43％，北仑区为39．29％，宁海县为73．08％，奉化市为25．00％，经统计学处理差异有统计学意义（P〈0．01）；除宁海外，其余3个县（市、区）毒螺检出率差异无统计学意义（P〉0．05）。从新增织纹螺栖息地象山采集的30份织纹螺样品，毒素测定值均≤400MU／100g肉，未检出毒螺。结论宁波市各栖息地的织纹螺带毒严重，是一种引起织纹螺中毒的原因食物。各栖息地织纹螺毒性存在差异，以宁海县的织纹螺带毒最普遍。毒螺的分布和毒性的强弱与地域相关。织纹螺毒素的毒性可消长，但无规律性。     

双壳贝类麻痹性贝毒抗性机制的研究

麻痹性贝毒(PSP)是一类神经肌肉麻痹剂,可以阻断电压门控钠离子通道,造成神经系统传输障碍而产生麻痹作用。某些双贝壳类对PSP毒素具有耐受性和抗性,其抗性机制可能与代谢速率、生物转化和钠通道突变等有关,其中钠通道突变是双壳贝类对PSP毒素产生抗性的最重要的分子机制。     

Drowning in Alaskan waters.

OBJECTIVE: To enumerate drowning fatalities in Alaska in order to identify risk factors and areas for intervention. METHODS: Information from death certificates, state troopers'' reports, and medical examiner reports were abstracted and analyzed. Rates were calculated using 1990 census figures as denominator data. RESULTS: There were 542 drowning fatalities in Alaska for the years 1988 to 1992. The 20-29 age group had the highest frequency and rate of drownings. The incidence rate for the state was 20 drownings per 100,000 population per year, almost 10 times higher than the overall U.S. rate of 2.11 per 100,000 per year. Incidence rates were highest among adolescent males (10-19), young adult males (20-29). Alaska Natives, and rural residents. Alaska Native males, ages 30-39 averaged 159 drownings per 100,000 per year, the highest drowning rates in the state. CONCLUSIONS: Drowning is a major public health concern in Alaska. People who fish commercially and young Native males are groups at high risk for drowning. Intervention efforts should be concentrated on these two populations.