Toxinas Algales en el Mar Argentino: nuevos hallazgos, nuevos desafíos / Algal Toxins in the Argentine Sea: new findings, new challenges

Resumen Las floraciones de algas nocivas son un problema cada vez más frecuente a nivel mundial que ocasiona severos daños sobre la salud pública, pérdidas económicas en acuicultura, perjuicios al turismo y episodios de mortalidad de poblaciones naturales de peces, aves y mamíferos marinos. Las toxinas son producidas por el fitoplancton y se acumulan en moluscos bivalvos que se alimentan por filtración del agua siendo estos los principales vectores de intoxicación humana. En el Mar Argentino, se han reportado toxinas marinas de origen microalgal asociadas con cuatro síndromes de intoxicación por moluscos. Los síndromes más graves por su extensión, frecuencia, toxicidad y organismos afectados, son los originados por el dinoflagelado Alexandrium cate-nella responsable de la Intoxicación Paralizante por Moluscos la cual ha ocasionado numerosas muertes humanas. Seguidamente, la más leve, en cuanto a gravedad y frecuencia, ha sido la Intoxicación Diarreica por Moluscos. En contraste, el ácido domoico, conocido como toxina amnésica de moluscos, no ha producido hasta ahora intoxicaciones humanas. Recientemente, se amplió el rango de toxinas para la región al registrarse las toxinas y los dinoflagelados productores de la Intoxicación Azaspirácidos por Moluscos. Además, se han detectado las potencialmente tóxicas Yessotoxinas y Espirolidos, cuyos mecanismos de acción y toxicidad están siendo aún evaluados a nivel mundial. Estas toxinas emergentes para la región, representan un riesgo potencial para la salud e inconvenientes socioeconómicos por el cierre de los sitios de explotación de moluscos. Ciertamente presentan un nuevo desafío, pues la detección y cuantificación sólo puede realizarse por medio de métodos basados en HPLC - espectrometría de masas, lo cual dificulta el monitoreo en laboratorios regionales en el país. La herramienta clave de manejo es la prevención, a través de políticas, regulaciones y sistemas de monitoreo y control de cada grupo de toxinas. A través de estas mejoras, se anticipa que no sólo disminuirá el número de afectados por estas intoxicaciones, si no que se podrán realizar vedas más eficientes, asegurando un equilibrio que proteja tanto la salud pública como el desarrollo de la industria pesquera.

Abstract Harmful algal blooms are an increasingly common problem worldwide, causing severe damage to public health, economic losses in aquaculture, damage to tourism and mortality events of natural populations of fish, birds and marine mammals. The toxins are produced by phytoplankton and accumulated in bivalve molluscs that feed on water filtration, being these main vectors of human intoxication. In the Argentine Sea marine toxins of microalgal origin have been reported associated with four shellfish poisoning syn-dromes. The most serious due to their extension, frequency, toxicity and affected organisms are those caused by the dinoflagellate Alexandrium catenella responsible for the Paralytic shellfish poisoning that has caused numerous human deaths. Then, the mildest, in severity and frequency, is the Diarrhetic shellfish poisoning. In contrast, domoic acid, known as Amnesic shellfish toxin, has not produced human intoxications yet. Recently, toxins and dinoflagellate species causing Azaspiracid shellfish poisoning have been re-corded, expanding the range of toxins for the region. In addition, the potentially toxic Yessotoxins and Spirolides have been detected, whose mechanism of action and toxicity is still being evaluated worldwide. These emerging toxins represent a potential risk to public health and socioeconomic activities due to the eventual closure of mollusc exploitation sites. They certainly present a new challenge, since detection and quantification can only be carried out using methods based on HPLC - mass spectrometry, which makes monitor-ing in regional laboratories difficult. Prevention through policies, regulations, and monitoring and control systems of each toxin group is the key management tool. These preventive measures are expected to contribute to reducing the number of poisonings and to ap-plying more efficient fisheries closures, ensuring a balance that protects both public health and the development of the fishing industry.

Risk assessment indexes for shellfish poisoning outbreak caused by red tide / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish the indexes and weights of risk assessment of shellfish poisoning outbreak caused by red tide.</p><p><b>METHODS</b>The risk assessment indexes were developed with the methods of literature review, brainstorm and expert consultation, and the weights of indexes were calculated by the method of analytic hierarchy process. The established indexes contained the risk possibility, impacts of public health, population vulnerability and resilience. The relative risk indexes(integrated risk indexes) of different shellfish poisoning were computed by combining hierarchy process and TOPSIS methods. Moreover, the weights of indexes were further used to generate absolute risk values by multiplying indexes.</p><p><b>RESULTS</b>Four primary indexes and 17 secondary indexes were identified for risk assessment of shellfish poisoning outbreak. Of 17 secondary indexes, the knowing rate of shellfish poisoning, medical accessibility, the number of people being affected, laboratory testing capacity and the habits of eating seafood of local residents had relatively large weights (0.0876, 0.0840, 0.0716, 0.0703 and 0.0644, respectively), which accounted for nearly 38% of the total weight. All consistency ratio (CR) were less than 0.1. The index system was applied in Cangnan county of Zhejiang province. The results showed the relative risk indexes of paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), neurotoxic shellfish poisoning (NSP) and amnesic shellfish poisoning (ASP) were 0.4526, 0.7116, 0.1657 and 0.2884, and the absolute risk values were 0.2542, 0.2668, 0.1907 and 0.2184, respectively. The risk orders of the 4 kinds of shellfish poisoning sorted by relative risk indexes and absolute risk values were consistent.</p><p><b>CONCLUSIONS</b>The indexes and weights of risk assessment of shellfish poisoning outbreak caused by red tide are established, which can provide scientific advice for prevention and control of shellfish poisoning outbreak.</p>

Toxic potential of palytoxin / 华中科技大学学报（医学）（英德文版）

This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

Doença de Haff complicada por falência de múltiplos órgãos após ingestão de lagostim: estudo de caso / Haff disease complicated by multiple organ failure after crayfish consumption: a case study

A doença de Haff é uma síndrome que consiste de rabdomiólise não explicada. Pacientes que apresentam a doença de Haff relatam ter ingerido pescado nas últimas 24 horas antes do início da doença. A maioria dos pacientes sobrevive apresentando breve recuperação. O presente artigo é o primeiro relato de doença de Haff complicada por falência de múltiplos órgãos após ingestão de lagostim. Um homem chinês de 66 anos de idade ingeriu lagostim cozido na noite de 23 de junho de 2013. Chegou ao hospital 2 dias mais tarde, sendo admitido à unidade de terapia intensiva. Após a admissão, o paciente recebeu o diagnóstico de doença de Haff complicada por falência de múltiplos órgãos. Apesar dos tratamentos de suporte e sintomático, a condição do paciente deteriorou, vindo o mesmo a falecer em consequência da doença. A doença de Haff é uma rara síndrome clínica que é, às vezes, mal diagnosticada. O diagnóstico precoce e o tratamento adequado são essenciais para prevenir a progressão para falência de múltiplos órgãos.

Haff disease is a syndrome consisting of unexplained rhabdomyolysis. Patients suffering from Haff disease report having eaten fish within 24 hours before the onset of illness. Most patients survive and recover quickly. The present study is the first report of Haff disease complicated by multiple organ failure after crayfish consumption. A 66-year-old Chinese man ate cooked crayfish on the night of June 23, 2013. He arrived at our hospital 2 days later and was admitted to the intensive care unit. After admission, the patient was diagnosed with Haff disease complicated by multiple organ failure. Despite supportive and symptomatic treatments, the condition of the patient deteriorated, and he died due to his illness. Haff disease is a rare clinical syndrome that is sometimes misdiagnosed. Early diagnosis and proper treatment are essential to prevent progression to multiple organ failure.

Detection of shellfish toxins from scallops in Guangzhou seafood market

To evaluate scallop safety in the Guangzhou seafood market, contents of shellfish toxins in adductor muscle, mantle skirts, gills and visceral mass of scallops were examined using enzyme-linked immunosorbent assay (ELISA) and mouse unit assay. The results showed that: paralytic shellfish poisoning contents were up to 37.44 µg/100 g by ELISA and 319.99 MU/100 g by mouse unit assay, which did not exceed the limits of national standards (80 µg/100g and 400 MU/100 g); the contents of diarrhetic shellfish poisoning were 142.04 µg/100g and 0.2 MU/100 g, which exceeded the national standard limits (60 µg/100g); neurotoxic shellfish poisoning was undetectable; the contents of amnesic shellfish poisoning reached 220.12 µg/100g (no limit value could be referred to) . In addition, these poisons were present mainly in visceral mass and gills rather than adductor muscle and mantle skirts, suggesting that these toxins accumulate in a tissue-specific manner.(AU)

Higiene alimentaria para la prevención de trastornos digestivos infecciosos y por toxinas / Food safety for the prevention of the infecious and toxine of the foodborne diseases

El principal factor que interviene en el origen y prevención de las enfermedades trasmitidas por los alimentos es la higiene alimentaria. Dichas enfermedades son causadas por la ingestión de alimentos o agua contaminados con microorganismos patógenos ocasionando una infección o por la ingestión de alimentos contaminados con toxinas. Los principales agentes involucrados son Escherichia Coli, Campylobacter, Salmonella, Shigella, Listeria Monocytogenes, Norovirus, virus Hepatitis A, Astrovirus, Rotavirus, y Virus Coxsackie. Toxinas producidas por hongos o por microflora marina y los contaminantes orgánicos persistentes pueden también causar serios problemas de salud. La inocuidad alimentaría ha tomado relevancia debido a una mayor exigencia por consumidores cada día más informados y por las demandas del comercio exterior. Medidas que aseguren una adecuada higiene alimentaría nos permitirá prevenir enfermedades, principalmente digestivas, causadas por variados agentes en los alimentos. Esto se logra por la implementación de las medidas propuestas por la Comisión Internacional conocida como Codex Alimentarius

Food Safety is the main factor involved in the origin and prevention of Food-borne diseases. These diseases are caused by either the intake of contaminated foods or water or by the intake of toxin-contaminated foods. Escherichia Coli, Campylobacter, Salmonella, Shigella and Listeria Monocytogenes, Norovirus, Hepatitis A virus, astrovirus, rotavirus, and coxsackie virus are the main causative agents involved in food-borne diseases. Toxins produced by fungi or marine microflora and the presence of persistent organic polluting agents can also cause serious health problems. Food safety has become an important topic due to a more demanding and informed consumer and the foreign food trade. Measures leading to ensure a better food safety will allow us to prevent various foodborne preventive diseases, mostly in the digestive system, caused by different etiological agents. This can be achieved through the implementation of the different measures proposed by the international commission called Codex Alimentarius

Environmental and health effects associated with Harmful Algal Bloom and marine algal toxins in China / 生物医学与环境科学（英文）

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.

Paralytic Shellfish Poisoning by Saxitoxin: Two case reports

Paralytic shellfish poisoning results from consumption of mollusks that have fed on dinoflagellates capable of producing neurotoxins such as saxitoxin. The saxitoxin is concentrated in the shellfish and acts by decreasing sodium-channel permeability, thereby blocking neuronal transmission in skeletal muscles. Symptoms including paresthesia, perioral numbness, perioral tingling, nausea, vomiting, extremity numbness, extremity tingling, dizziness, ataxia, dysphagia, and weakness have been reported. In serious cases, respiratory hold may occur up to 6~24 hours after ingestion. Generally, the treatment for paralytic shellfish poisoning is supportive care, but mechanical ventilation is needed in serious cases acompanied by respiratory hold. We experienced two cases of paralytic shellfish poisoning. Respiratory hold was presented in one case and only mild paresthesia in the other case. After supportive management, including mechanical ventilation in former case, both patients were discharged without sequalae.