Ciguatera fish poisoning: First reported case in Sabah, Malaysia

Ciguatera fish poisoning (CFP) is the most common natural marine toxin poisoning worldwide and yet under recognised in Malaysia. We report the first confirmed case of CFP in Sabah with severe neurological, cardiovascular and gastrointestinal manifestations after consumption of emperor snapper. Early recognition of CFP is important because it will result in improved patient care and public health intervention.

Nanomaterials based optical and electrochemical sensing of histamine: Progress and perspectives

Histamine is known to be a principal causative agent associated with marine food poisoning outbreaks worldwide, which is typically formed in the contaminated food by decarboxylation of histidine by bacterial histidine decarboxylase. Upon quantification of histamine in different food products, one can comment on the quality of the food and use it as an indicator of the good manufacturing practices and the state of preservation. The United States Food and Drug Administration (FDA) has established 50 ppm (50 mg/kg) of histamine as the chemical index for fish spoilage. Consumption of foods containing histamine higher than the permissible limit can cause serious health issues. Several methods have been developed for the determination of histamine in a variety of food products. The conventional methods for histamine detection such as thin layer chromatography, capillary zone electrophoresis, gas chromatography, colorimetry, fluorimetry, ion mobility spectrometry, high-performance liquid chromatography, and enzyme-linked immunosorbent assay (ELISA), are being used for sensitive and selective detection of histamine. However, there are a number of disadvantages associated with the conventional techniques, such as multi-step sample processing and requirement of expensive sophisticated instruments, which restrict their applications at laboratory level only. In order to address the limitations associated with the traditional methods, new approaches have been developed by various research groups. Current advances in nanomaterial-based sensing of histamine in different food products have shown significant measurement accuracy due to their high sensitivity, specificity, field deployability, cost and ease of operation. In this review, we have discussed the development of nanomaterials-based histamine sensing assays/strategies where the detection is based on optical (fluorescence, surface enhanced Raman spectroscopy (SERS), localized surface plasmon resonance) and electrochemical (impedimetric, voltammetry, potentiometric, etc.). Further, the advantages, disadvantages and future scope of the nanomaterials-based histamine sensor research are highlighted.

[Study on tetrodotoxin detection and toxic puffer fish identification of roasted fish fillet at the retail in Beijing and Qingdao]

OBJECTIVE

The roasted fish fillet sample at the retail collected in Beijing and Qingdao were detected for TTX, and the TTX positive samples was analyzed for fish species identification.

METHODS

TTX was tested by EUSA method and the cytochrome c oxidase I (COI) genome of TTX-positive samples was extracted and identified by DNA barcode.

RESULTS

Totally, 90 samples were tested by EUSA and 58 (64.4%) samples were positive for TTX with the levels ranging from 0.10 mg/kg to 63.81 mg/kg. Among the TTX positive samples, 24 (41.3%) were identified containing toxic puffer fish and 21 (87.5%) were Lagocephalus lunaris, the highly toxic puffer fish.

CONCLUSION

Some roasted fish fillet samples obtained from the retail in two cities were positive for TTX and contained toxic puffer fish. Based on these results, we suggest that roasted fish fillet producers should prevent toxic puffer fish from mixing in the raw material and the I regulators should strengthen the TTX surveillance and product labeling supervision of roasted fish fillet.

Trends in blood mercury concentrations and fish consumption among U.S. women of reproductive age, NHANES, 1999-2010

BACKGROUND

Consumption of finfish and shellfish is the primary exposure pathway of methylmercury (MeHg) in the US. MeHg exposure in utero is associated with neurodevelopmental and motor function deficits. Regulations and fish advisories may contribute to decreased exposure to mercury over time.

OBJECTIVES

Combine fish tissue mercury (FTHg) concentrations and 1999-2010 NHANES blood mercury concentrations and fish consumption data to investigate trends in blood mercury concentrations, fish consumption, and mercury intake in women of reproductive age.

METHODS

Blood MeHg was calculated from the blood total and inorganic concentrations. Dietary datasets were combined to estimate 30-day fish consumption, then combined with FTHg concentrations to estimate mercury intake and mercury concentration in the fish consumed. Non-linear and logistic regression analyses were used to evaluate trends over time.

RESULTS

Regression analysis found NHANES 1999-2000 to have higher blood MeHg concentrations than the mean of the later releases (p<0.0001) and a positive quadratic trend since 2000 (p=0.004). No trend was observed in fish consumption amount or mercury intake. A decreasing trend was found in the ratio of mercury intake to fish consumed (p=0.04).

CONCLUSIONS

The analyses found blood MeHg concentrations in NHANES 1999-2000 to be significantly higher than the mean of the later releases. There was no trend in fish consumption amount across the study period. The analysis found a decreasing trend in the ratio of mercury intake to fish consumed, consistent with women shifting their consumption to fish with lower mercury concentrations.

[Histamine food poisonings in Japan and other countries]

Histamine food poisonings are allergy-like food poisonings caused by the ingestion of spoiled fish containing markedly elevated histamine levels. We examined histamine food poisonings in Japan from 1998 to 2008. In average 8 food poisonings and 150 cases were reported annually and there was no fatality case. In more than 80% of remaining food samples, histamine content exceeded 20 mg/100 g. These poisonings were caused by tuna, billfish (marlin) and mackerel, which contained higher level of histamine than other fishes in histamine food poisonings in Japan. Cooking methods of these fishes were mainly "broiled". We also studied histamine food poisonings in other countries. Tuna was the main fish in histamine food poisonings reported to Centers for the Disease Control and Prevention (CDC) in the US and Ozfoodnet in Australia from 2000 to 2006. In the US, histamine food poisonings were also caused by mahimahi and escolar fish. Our review will be useful for in taking measures to reduce risk of histamine food poisonings.

Three successive cases of enteric anisakiasis

Enteric anisakiasis is relatively rare, and the preoperative diagnosis is difficult. We report 3 cases of enteric anisakiasis: 1 was confirmed by operation, and the other 2 cases were suspected by the patient history. The 1st patient was a 48-year-old female presenting with abdominal pain. An abdominal computed tomography scan showed a dilated small intestine and accumulation of ascites. We performed partial resection of the small intestine, and an Anisakis nematode was found on the wall of the resected bowel. After surgery, the detailed history revealed that the patient consumed a raw sardine with vinegar and miso, fermented soybean paste. Three days after her operation, 2 men presenting with abdominal pain visited the hospital, and computed tomography scans of the patients showed dilated small intestines and accumulation of ascites. By taking patient histories, we found that both of them consumed sardines with vinegar and miso, and both were given conservative treatment with fasting and transfusion. By the experience of the 1st case, we could diagnose the following 2 cases as having enteric anisakiasis. In conclusion, the possibility of anisakiasis should be considered in patients with abdominal pain after ingesting raw fish, especially when intestinal obstruction is suspected.

Emergence of Imported Ciguatera in Europe: Report of 18 Cases at the Poison Control Centre of Marseille

BACKGROUND

Ciguatera is a disease caused by the ingestion of fish containing the toxins of Gambierdiscus toxicus. This dinoflagellate is frequently found in damaged coral reef systems. Previously rare in Europe, this disease entity is now seen in tourists returning from tropical countries.

CASE SERIES

Eighteen patients were examined between 1997 and 2002. Nine poisonings occurred in Atlantic Ocean islands, eight in Pacific Ocean islands, and one in the Egyptian Red Sea coast. Gastrointestinal signs were always present in the Atlantic areas, but were less severe or absent in the Pacific areas. All patients had sensory disturbances, and two of them had motor disturbances affecting the respiratory muscles and leading to the death of a 73-year-old man in Cuba. The 17 surviving patients returned to France and for 2 to 18 months suffered from arthralgias, myalgias, or pruritus.

CONCLUSION

Ciguatera is a newly imported intoxication in Europe. As the number of international tourists grows each year, this type of poisoning will be seen more frequently. Furthermore, as the condition of coral reefs declines around the world and the prevalence of G. toxicus increases, physicians in non-tropical countries should be prepared to manage such poisoned patients.

Identification of species and measurement of tetrodotoxin in dried dressed fillets of the puffer fish, Lagocephalus lunaris

The toxicity and species of dried dressed fish fillets were investigated. Three of seven dried dressed fish fillets were found to be toxic, with their levels of toxicity ranging from 9 to 18 mouse units per g. The toxin preparation was further purified and identified as tetrodotoxin and anhydrotetrodotoxin by high-performance liquid chromatography and gas chromatography-mass spectroscopy. The species of these fillets could not be distinguished from Lagocephalus lunaris by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis or restriction site and sequence analysis of a polymerase chain reaction amplicon of the cytochrome b gene. These fish fillets were identified as L. lunaris on the basis of their protein patterns and gene characteristics. Furthermore, the toxic samples contained low levels of tetrodotoxin and its derivative.

Identification of tetrodotoxin and fish species in a dried dressed fish fillet implicated in food poisoning

There were five victims of neurotoxic food poisoning from a dried dressed fish fillet in Changhua County, Taiwan, in February 2000. The toxicity of the dried dressed fish fillets was 243 mouse units per g according to a tetrodotoxin bioassay. The partially purified toxin was identified as tetrodotoxin and anhydrotetrodotoxin. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype as that of the toxic puffer fish Lagocephalus lunaris. The same single restriction site for Hinfl was found in the polymerase chain reaction (PCR) products from the dried dressed fish fillet and the muscle of L. lunaris, yielding two DNA fragments of 170 and 206 bp. However, no restriction site for Hinfl was found in the PCR products from other toxic puffer fishes, including Takifugu niphobles, Takifugu oblongus, and Takifugu rubripes. Therefore, the species of the dried dressed fish fillet was identified as L. lunaris and its causative agent was identified as tetrodotoxin.

Food poisoning outbreak from contaminated fish-balls

On February 9th, 1998, a food poisoning outbreak occurred at a boarding school for underprivileged students. An unmatched case-control study was done. An environmental survey, laboratory study of rectal swab culture, fish-balls, water and the cooking utensils were also performed. There were 132 suspect cases, of which the attack rate in teachers was 9.8 per cent (4/41), 16.7 per cent (1/6) in the food handlers and 15.7 per cent (127/810) in the students. The median incubation period was 18 hours. Analysis of food consumption revealed those who ate lunch noodles had the highest risk (OR 3.8, 95% CI 0.6-5.9). In details of food components, those who ate fish-balls in curry had the only significant risk (OR 3.5, 95% CI 1.2-0.8) of becoming ill when compared to those who did not. Fish-balls in noodles and curry had a dose response relationship. Bacterial culture from 25 grams of fish-balls was positive for Vibrio parahaemolyticus. The fish-balls in noodles and curry were identified as the implicated food. The modes of contamination were uncooked food, cooking utensils and the food handlers. The manufacturer, which had no license to operate and had poor standards of sanitation, was closed by the Food and Drug Administration.

A small outbreak of listeriosis potentially linked to the consumption of imitation crab meat

A small outbreak of listeriosis involving two previously healthy adults occurred in Ontario. Food samples obtained from the refrigerator of the patients included imitation crab meat, canned black olives, macaroni and vegetable salad, spaghetti sauce with meatballs, mayonnaise and water. All of the samples except the water contained Listeria monocytogenes. The three most heavily contaminated samples were the imitation crab meat, the olives and the salad which contained 2.1 x 109, 1.1 x 107 and 1.3 x 106 cfu g-1, respectively. L. monocytogenes serotype 1/2b was isolated from the patients, as well as from the opened and unopened imitation crab meat. Molecular typing of the isolates by both randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) typing demonstrated the imitation crab meat and clinical strains to be indistinguishable. Challenge studies performed with a pool of L. monocytogenes strains showed that imitation crab meat, but not olives, supported growth of the organism. In this study we have shown for the first time the potential involvement of imitation crab meat in a small outbreak of listeriosis. In terms of disease prevention, temperature control is critical to prevent or reduce the growth of this foodborne pathogen. In addition, with refrigerated products having a long (> 30 d) shelf life, additional safety factors must be used to prevent the growth of foodborne pathogens such as L. monocytogenes.

Histamine fish poisoning revisited

Histamine (or scombroid) fish poisoning (HFP) is reviewed in a risk-assessment framework in an attempt to arrive at an informed characterisation of risk. Histamine is the main toxin involved in HFP, but the disease is not uncomplicated histamine poisoning. Although it is generally associated with high levels of histamine (> or =50 mg/100 g) in bacterially contaminated fish of particular species, the pathogenesis of HFP has not been clearly elucidated. Various hypotheses have been put forward to explain why histamine consumed in spoiled fish is more toxic than pure histamine taken orally, but none has proved totally satisfactory. Urocanic acid, like histamine, an imidazole compound derived from histidine in spoiling fish, may be the "missing factor" in HFP. cis-Urocanic acid has recently been recognised as a mast cell degranulator, and endogenous histamine from mast cell degranulation may augment the exogenous histamine consumed in spoiled fish. HFP is a mild disease, but is important in relation to food safety and international trade. Consumers are becoming more demanding, and litigation following food poisoning incidents is becoming more common. Producers, distributors and restaurants are increasingly held liable for the quality of the products they handle and sell. Many countries have set guidelines for maximum permitted levels of histamine in fish. However, histamine concentrations within a spoiled fish are extremely variable, as is the threshold toxic dose. Until the identity, levels and potency of possible potentiators and/or mast-cell-degranulating factors are elucidated, it is difficult to establish regulatory limits for histamine in foods on the basis of potential health hazard. Histidine decarboxylating bacteria produce histamine from free histidine in spoiling fish. Although some are present in the normal microbial flora of live fish, most seem to be derived from post-catching contamination on board fishing vessels, at the processing plant or in the distribution system, or in restaurants or homes. The key to keeping bacterial numbers and histamine levels low is the rapid cooling of fish after catching and the maintenance of adequate refrigeration during handling and storage. Despite the huge expansion in trade in recent years, great progress has been made in ensuring the quality and safety of fish products. This is largely the result of the introduction of international standards of food hygiene and the application of risk analysis and hazard analysis and critical control point (HACCP) principles.

Out-of-hospital and emergency department management of epidemic scombroid poisoning

OBJECTIVE

To report two epidemic outbreaks of scombroid food poisoning and their emergency medical services (EMS) response and emergency department (ED) treatment, analyzing the impact of early physician involvement and on-line medical control.

METHODS

Retrospective case series of two multiple-casualty incidents (MCIs) involving scombroid food poisoning.

RESULTS

A total 57 patients were treated from two separate incidents, with 30 patients transported to area hospitals. One patient required treatment with a cardiac medication in the field and another patient eventually required hospital admission. On-scene medical control (incident 1) and early identification of the index case (incident 2) were instrumental to out-of-hospital care interventions and conservation of resources. Patient triage, field treatment, and hospital transport were expedited, with some patients treated and released from the scene.

CONCLUSIONS

Immediate diagnosis of a food-borne illness in the out-of-hospital setting allows rapid treatment at the scene and allows for the efficient transport of multiple patients to a single receiving facility. EMS medical directors should be able to immediately respond to such incidents to make presumptive diagnoses and accurately direct patient care. When this is not possible, early identification of the index case facilitates early diagnosis and treatment.

Behavioral effects of prenatal and adult exposure to toxic chemicals found in Lake Ontario fish: two methodological approaches

Two research approaches are described that were used to determine behavioral changes following a diet of Lake Ontario fish. Approach 1 involved the correlational method, in which human subjects voluntarily ate contaminated Lake Ontario fish. Demographic information, data on the amount of Lake Ontario fish consumed, and control variables were obtained during an interview. Respondents' behavior, as well as the behavior of their children, then was measured. Because subjects were not assigned randomly to eat or not eat Lake Ontario fish, other variables that might have influenced both consumption of fish and behavior had to be considered. Therefore, confounding variables were measured and their influence controlled for using statistical techniques. Approach 2 involved the experimental method using laboratory rats, where subjects were assigned randomly to receive a diet of environmentally contaminated Lake Ontario salmon, relatively uncontaminated Pacific Ocean salmon, or no salmon. Since the rats fed Lake Ontario salmon behaved differently than the other two groups on nine tasks, it was concluded that the contaminants in Lake Ontario salmon caused behavioral changes. Random assignment of subjects to groups eliminated competing explanations. If similar behavioral (e.g., emotional or cognitive) results were obtained using the two approaches, then the results utilizing rats probably could be generalized to humans, and the correlational results found in humans probably were due to a cause and effect relationship.

Fish consumption advisories and outreach programs for Southeast Asian immigrants

Southeast Asian immigrants and refugees, in particular the Hmong people of Laos, have settled in large numbers in metropolitan areas of Minnesota. These communities, accustomed to hunting and fishing for food in Laos, now fish in some of the most contaminated waters of Minnesota. Fishing and fish-preparation customs of their homeland emphasize using all fish caught and discarding very little waste. These practices result in a potentially high exposure to PCBs and mercury. Educational outreach efforts to inform this population of the potential health hazards from consuming the fish are hindered by language and cultural barriers. While most Hmong anglers welcome information about contaminants and fishing, the typical press releases and mailings that convey fish advisory information to the public do not reach this community. The Minnesota Department of Health and the Minnesota Department of Natural Resources collaborated to determine the health messages and communication methods that would best meet the needs of these communities. Using the results of interviews and a behavioral survey, the Minnesota Department of Health has tailored fish consumption advisories to meet the unique needs of Southeast Asian anglers. Over the past four years, educational programs involving specialized advisories, translations, signs, a Hmong language video, and workshops have been used to inform Hmong anglers and other Southeast Asians about fish contaminants.

A massive outbreak of type E botulism associated with traditional salted fish in Cairo

In April 1991, 91 hospitalized patients in Cairo were reported to the Egyptian Ministry of Health with botulism intoxication. To define the spectrum of illness and identify a food vehicle, 45 patients were interviewed and a case-control investigation was conducted among families of 5 hospitalized patients. Clinical specimens and specimens of implicated food were tested for toxin and cultured for Clostridium botulinum. Hospitalized patients had symptoms consistent with botulism; 18 (20%) of 91 reported patients died. Illness was associated with eating faseikh (uneviscerated, salted mullet fish; lower 95% confidence limit of odds ratio = 6.6, P < .001). All 5 case-families purchased faseikh from one shop. Very high levels of type E botulinal toxin were detected in faseikh reported to be purchased from the implicated shop; C. botulinum type E was isolated from cultures of clinical specimens and from the faseikh. This is the first documented outbreak of botulism in Egypt and the largest type E outbreak ever reported.

[Imported food poisoning caused by fish toxins (ciguatoxin)]

Various types of fish-poisoning mainly occur in tropical areas. Saxitoxin, tetrodotoxin, scombrotoxin and clupeotoxin are heat labile while ciguatoxin, in contrast, is heat stable thus it may be the source of severe poisoning even in case of thorough cooking and baking. In December 1987 a mass alimentary poisoning occurred following ingestion of fish meat in a group returning from Cuba. The most severe case was admitted to our department with symptoms of extended paresis. Diagnosis of ciguatoxin poisoning was established based upon the history, clinical features and laboratory results. Nowadays exotic, remote "Fish-poisoning" cases have to be taken into consideration even in our country.

First identification of acute tetrodotoxin-associated food poisoning in Taiwan

Attempt was made to elucidate the responsible toxin in fish which recently caused food poisoning in Ilan County, Taiwan. The causative fish was assayed for anatomical distribution of toxicity (as tetrodotoxin). The roe showed the highest toxicity (1200 mouse units per gram, abbreviated as MU/g), followed by the dermis (150 MU/g) and muscle (120 MU/g). The toxins were partially purified from the methanolic extracts of the fish muscle and roe by ultrafiltration and Bio-Gel P-2 column chromatography. Thin-layer chromatography, cellulose acetate membrane electrophoresis and high performance liquid chromatography analysis demonstrated that the toxins consisted of tetrodotoxin and anhydrotetrodotoxin. It was concluded that the causative agent of the above food poisoning was tetrodotoxin.

Histamine food poisoning: toxicology and clinical aspects

Histamine poisoning can result from the ingestion of food containing unusually high levels of histamine. Fish are most commonly involved in incidents of histamine poisoning, although cheese has also been implicated on occasion. The historic involvement of tuna and mackerel in histamine poisoning led to the longtime usage of the term, scombroid fish poisoning, to describe this food-borne illness. Histamine poisoning is characterized by a short incubation period, a short duration, and symptoms resembling those associated with allergic reactions. The evidence supporting the role of histamine as the causative agent is compelling. The efficacy of antihistamine therapy, the allergic-like symptomology, and the finding of high levels of histamine in the implicated food suggest strongly that histamine is the causative agent. However, histamine ingested with spoiled fish appears to be much more toxic than histamine ingested in an aqueous solution. The presence of potentiators of histamine toxicity in the spoiled fish may account for this difference in toxicity. Several potentiators including other putrefactive amines such as putrescine and cadaverine have been identified. Pharmacologic potentiators may also exist; aminoguanidine and isoniazid are examples. The mechanism of action of these potentiators appears to be the inhibition of intestinal histamine-metabolizing enzymes. This enzyme inhibition causes a decrease in histamine detoxification in the intestinal mucosa and results in increased intestinal uptake and urinary excretion of unmetabolized histamine.

Food poisoning and fish

FOOD POISONING caused by the consumption of fishery products is reviewed. More detailed descriptions are given of those types with some special or unique association with fish such as botulism, Vibrio para haemolyticus and scombrotoxin poisoning.

Scombroid-type poisoning induced by the ingestion of smoked kahawai

Three incidents of presumptive scombroid poisoning were reported in the Wellington area in 1973. Two of these cases were attributed to canned mackerel and the third to smoked kahawai. The marked similarity of the symptoms of the kahawai poisoning to those of the other two outbreaks of scombroid fish poisoning and the relief following anti-histamine therapy suggests that the poisoning arose from a similar source. Analysis of the extracts from the smoked kahawai revealed an abnormally high level of histamine and the presence of an unknown toxin. The unknown substance resembled saurine, the toxin that has been incriminated in scromboid poisoning, thus suggesting that scombroid intoxication may not be confined to fish belonging to the sub-order Scombroidei.