Puffer fish poisoning in Bangladesh: clinical and toxicological results from large outbreaks in 2008

Emergent toxins in North Atlantic temperate waters: a challenge for monitoring programs and legislation

Harmful Algal Blooms (HAB) are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

Family tetrodotoxin poisoning in Reunion Island (Southwest Indian Ocean) following the consumption of Lagocephalus sceleratus (Pufferfish)

Pufferfish poisoning has rarely been reported in the southwestern Indian Ocean and in the French overseas territories. In Reunion Island, the last notified documented case occurred in 1989 and people are no longer aware of the potential toxicity of pufferfish. We report a family hospitalized for a tetrodotoxin poisoning following the consumption of Lagocephalus sceleratus caught on the coast of Reunion Island in September 2013. Two patients presenting acute vital functions failures were admitted in an ICU. Ten people were admitted simultaneously to the emergency department after consuming L. sceleratus with signs of toxicity appearing within 2 hours. Treatment was supportive, but included the need for mechanical ventilation for two patients. All those affected had complete and uneventful recoveries within a few days. The fish consumed was identified as L. sceleratus, a species known to contain tetrodotoxin. The diagnosis of tetrodotoxin poisoning was suggested by typical clinical manifestations together with the history of very recent consumption of tetrodotoxin-containing fish. Tetrodotoxin was later detected at high levels in food remnants. To the best of our knowledge, there has been no documented case series of tetrodotoxin poisoning reported from Reunion Island for the last 25 years and from the entire Indian Ocean area since 1998. Pufferfish intoxication is one of the most common causes of poisoning among people in coastal regions of Asia but it has also recently been reported in areas where it was previously unknown, particularly along the Mediterranean shores and in Spain. Public health education in French overseas territories and along the Mediterranean shores should be adapted to include increased awareness of the danger of consuming pufferfish. Health teams must be aware of such clinical presentations.

Tetrodotoxin: chemistry, toxicity, source, distribution and detection

Tetrodotoxin (TTX) is a naturally occurring toxin that has been responsible for human intoxications and fatalities. Its usual route of toxicity is via the ingestion of contaminated puffer fish which are a culinary delicacy, especially in Japan. TTX was believed to be confined to regions of South East Asia, but recent studies have demonstrated that the toxin has spread to regions in the Pacific and the Mediterranean. There is no known antidote to TTX which is a powerful sodium channel inhibitor. This review aims to collect pertinent information available to date on TTX and its analogues with a special emphasis on the structure, aetiology, distribution, effects and the analytical methods employed for its detection.

Microbial diversity associated with tetrodotoxin production in marine organisms

Tetrodotoxin (TTX), is a potent neurotoxin found in genetically diversed organisms. Many TTX producing microorganism have also been isolated from TTX bearing animals. The TTX producing microbes found in four different phylum (Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes), the Proteobacteria are the dominating one. In most of the cases, TTX producing microbes are found in the intestine of the TTX producing vector indicating the origin of TTX through food chain. This paper reviews the TTX and its analogs and the geographic distribution of TTX in symbiotic microorganism and its production.

An improved competitive inhibition enzymatic immunoassay method for tetrodotoxin quantification

Quantifying tetrodotoxin (TTX) has been a challenge in both ecological and medical research due to the cost, time and training required of most quantification techniques. Here we present a modified Competitive Inhibition Enzymatic Immunoassay for the quantification of TTX, and to aid researchers in the optimization of this technique for widespread use with a high degree of accuracy and repeatability.

Severe Tetrodotoxin Poisoning after Consumption of Lagocephalus sceleratus (Pufferfish, Fugu) Fished in Mediterranean Sea, Treated with Cholinesterase Inhibitor

Lagocephalus sceleratus, or better known as the pufferfish, or fugu, is widespread in Asia and Indo-Pacific regions. It is a poisonous fish containing tetrodotoxin (TTX) which is a potent neurotoxin. In the Far East, fugu is considered a delicate dish, especially in Japan where it is prepared by experts. Nevertheless, poisoning from Lagocephalus sceleratus is not a rare event. Recent data from Japan indicate an incidence of 45 patients per year and a mortality rate of 11%. Mediterranean sea is not the natural habitat of Lagocephalus sceleratus. However, by now multiple reports have established a firm presence of Lagocephalus sceleratus in Mediterranean region as well. This phenomenon is explained by migration of pufferfish across the Suez Channel (lessepsian migration) (Eisenman et al., 2008, Bentur et al., 2008). With lessepsian migration came the first reports of TTX poisoning in the Mediterranean region. We report a patient with a particularly severe and life-threatening TTX poisoning caused by consumption of Lagocephalus sceleratus and treated by cholinesterase inhibitor to a complete and uneventful recovery.

Analytical challenges: determination of tetrodotoxin in human urine and plasma by LC-MS/MS

Tetrodotoxin (TTX) is a powerful sodium channel blocker found in puffer fish and some marine animals. Cases of TTX poisoning most often result from puffer fish ingestion. Diagnosis is mainly from patient’s signs and symptoms or the detection of TTX in the leftover food. If leftover food is unavailable, the determination of TTX in the patient’s urine and/or plasma is essential to confirm the diagnosis. Although various methods for the determination of TTX have been published, most of them are for food tissue samples. Dealing with human urine and blood samples is much more challenging. Unlike in food, the amount of toxin in the urine and blood of a patient is generally extremely low; therefore a very sensitive method is required to detect it. In this regard, mass spectrometry (MS) methods are the best choice. Since TTX is a very polar compound, there will be lack of retention on conventional reverse-phase columns; use of ion pair reagent or hydrophilic interaction liquid chromatography (HILIC) can help solve this problem. The problem of ion suppression is another challenge in analyzing polar compound in biological samples. This review will discuss different MS methods and their pros and cons.

Social ecological analysis of an outbreak of pufferfish egg poisoning in a coastal area of Bangladesh

Recurrent outbreaks of marine pufferfish poisoning in Bangladesh highlight the need to understand the context in which the outbreaks occurred. In a recent outbreak investigation, a multidisciplinary team conducted a mixed-method study to identify the demography and clinical manifestation of the victims and to explore different uses of pufferfish, and local buying, selling, and processing practices. The outbreak primarily affected a low income household where an elderly woman collected and cooked pufferfish egg curry. Nine persons consumed the curry, and symptoms developed in 6 (67%) of these persons. Symptoms included vomiting, diarrhea, paresis, and tingling sensation; 2 (22%) persons died. The unstable income of the affected family, food crisis, and the public disposal of unsafe pufferfish byproducts all contributed to the outbreak. A multi-level intervention should be developed and disseminated with the participation of target communities to discourage unsafe discarding of pufferfish scraps and to improve the community knowledge about the risk of consuming pufferfish.