Crab allergen exposures aboard five crab-processing vessels

Aerosolized crab allergens are suspected etiologic agents for asthma among crab-processing workers. The objectives of this study were to characterize crab allergen concentrations and respiratory symptom prevalence among processing workers aboard crab-processing vessels. A cross-sectional survey of five crab-processing vessels was conducted near Dutch Harbor, Alaska. Crab allergen concentrations were quantified during specific work activities with 25 personal air samples collected on polytetrafluoroethylene filters and analyzed by a competitive IgE immunoassay technique. Two standardized respiratory questionnaires were used to assess respiratory symptoms suggestive of bronchitis or asthma in 82 workers. Aerosolized crab allergen concentrations ranged from 79 ng/m3 to 21,093 ng/m3 (mean = 2797 ng/m3, SD = 4576 ng/m3). The highest concentrations were measured at butchering/degilling work stations, which were combined on the smallest vessel. A significant percentage of workers reported development of respiratory symptoms during the crab-processing season. Cough developed in 28% of workers, phlegm in 11% of workers, and wheeze and other asthma-like symptoms developed in 4% of workers. Despite variations in crab allergen levels, respiratory symptom prevalence was similar across all job categories. Substantial concentrations of crab allergen exposure were measured, as well as the potential for wide variability in exposure during crab processing aboard vessels. The high prevalence of reported respiratory symptoms across all job categories suggests potential adverse respiratory effects that should be further characterized by prospective studies using pulmonary function and serology testing, and rigorous exposure characterization.

Isolation of Prorocentrum lima (Syn. Exuviaella lima) and diarrhetic shellfish poisoning (DSP) risk assessment in the Gulf of California, Mexico

A benthic toxic dinoflagellate identified as Prorocentrum lima (Syn. Exuviaella lima), and designated as strain PRL-1, was isolated from the coast of El Pardito (Coyote) Island in Baja California Sur, Mexico, after a fisherman poisoning incident involving consumption of liver from Lutjanus colorado, and Mycteroperca prionura fish. Purification and culturing was done in ES-Si medium, under 12:12 light/dark cycle (4 x 20 W cool-white fluorescent lamps), at 22 degrees C and constant stirring during 28 days. Whole cells were toxic to Artemia franciscana and its methanolic extract to mouse and to the marine yeast Debaryomyces hansenii. Chromatographic analysis (TLC and HPLC-MS) of such extract indicated an unusual proportion (1:2) okadaic acid (OA) and dinophysistoxin-1 (DTX-1). Estimated total toxin content by mouse bioassay (based on OA toxicity) was 19 pg/cell, a value significantly higher than that found by HPLC-MS (about 5.2 pg/cell, taking into account OA and DTX-1 only), suggesting that additional toxic components of unidentified nature are detected with the bioassay. This is the first report of a successful isolation and culturing of a toxic dinoflagellate from the Gulf of California, Mexico.

Barnacle hypersensitivity

BACKGROUND

the aim of the present study is to investigate the responsible mechanism of different adverse reactions suffered by five patients, aged between six and thirty years-old, after consumption of barnacle. The symptoms were angioedema, dyspnea, generalized urticaria, conjunctivitis and one of them suffered from anaphylactic reaction. Four patients had personal atopic history.

METHODS

the allergic study included prick by prick test with raw and boiled barnacle and prick-test with a standardized battery of shellfish and neumoallergens, specific-IgE determination to barnacle, crustacean and house-dust-mite and SDS-PAGE immunoblotting to barnacle. Even though an oral challenge was proposed to three of the patients, they were reluctant to do the test and eventually the challenges were not carried out.

RESULTS

prick to prick tests were positive to barnacle for all of them. Specific-IgE was found in four patients. The western blotting results showed an IgE-binding band whose apparent molecular mass ranged between 58 and 68 kDa.

CONCLUSIONS

barnacle could induce IgE-mediated adverse reaction. Our study has demonstrated the presence of an IgE-binding protein in barnacle extracts ranged between 58 and 68 kDa of molecular mass. It has not been previously described a crustacean allergen with the same molecular mass, so it could be a specific allergen from barnacle. We believe that further study will confirm this is the case.

Basis for a new procedure to eliminate diarrheic shellfish toxins from a contaminated matrix

The natural contamination of shellfish with diarrheic shellfish toxins (DSP) has important public health implications. To avoid the economic effects of toxic episodes on shellfish farmers and the related industry, research on artificial methods alternative to the natural detoxification of shellfish is needed. Because the usual thermal processes are not efficient, alternative technologies have to be studied. Here preliminary results are presented about the lability of the DSP toxin okadaic acid in a supercritical atmosphere of carbon dioxide with acetic acid. Most of the toxin is eliminated (up to 90%), and the biological activity against its target enzyme is also severely affected (up to 70% reduction). Detoxification of contaminated shellfish requires a partial dehydration, and the detoxification yield is lower than that obtained with free toxin. Mass spectrometry experiments suggest that acetylation of the toxin molecule is not the basis of the inactivating mechanism, but a conformational change is suggested. This is the first report of the use of supercritical fluids to inactivate toxins.

Decimal reduction times of Pyrodinium bahamense var. compressum and Escherichia coli in chlorine- and ultraviolet-treated seawater

AIMS

Decimal reduction times (D-values) of the vegetative cells of Pyrodinium bahamense var. compressum and Escherichia coli in ultraviolet- and chlorine-treated seawater were established.

METHODS AND RESULTS

The cells of the test organisms were exposed to ultraviolet- and chlorine-treated seawater and maintained at 20-35 ppt salinity and 20 to 35 degrees C. The dinoflagellate cells which cause Paralytic Shellfish Poisoning (PSP) were found to be more resilient than the bacterial cells. Ultraviolet treatment was found to be more effective than chlorine to both test organisms. Irreversible morphological changes in the treated dinoflagellate cells were noted, including protoplast discoloration, cellular membrane leakage and damage to the thecal armour.

CONCLUSIONS

The vegetative cells of both test organisms in seawater were more sensitive to ultraviolet treatment than to chlorine exposure. Generally, the dinoflagellate cells were less susceptible than bacterial cells to both disinfection treatments.

SIGNIFICANCE AND IMPACT OF THE STUDY

Results of this study may have significant implications in depuration procedures for molluscs and cleaning protocols for ballast waters of ships.

[House dust mite-crustaceans-molluscs syndrome. A rare variant of food allergy in primary sensitization to inhaled allergens]

80% of all cases in food allergy in adults are preceded by a clinical or subclinical sensitisation to inhalative allergens. Food allergy is caused by cross-reactions between ingested food and inhaled particles. We report a patient suffering from the house-dust mite-crustaceans-molluscs-syndrome. Here, house-dust mite is the sensitising agent, therefore even first ingestion of invertebrates such as snails, shrimps, mussels or oysters can lead to severe anaphylaxis.

Aspirin enhances the induction of type I allergic symptoms when combined with food and exercise in patients with food-dependent exercise-induced anaphylaxis

We examined the effect of aspirin as a substitute for exercise in inducing urticaria/anaphylaxis in three patients with food-dependent exercise-induced anaphylaxis (FDEIA). Two of the patients had specific IgE antibodies to wheat and the other had antibodies to shrimp. Administration of aspirin before ingestion of food allergens induced urticaria in one patient and urticaria and hypotension in another, while aspirin alone or food alone elicited no response. The third patient developed urticaria only when he took all three items, i.e. aspirin, food and additional exercise, whereas provocation with any one or or two of these did not induce any symptoms. These findings suggest that aspirin upregulates type I allergic responses to food in patients with FDEIA, and further shows that aspirin synergizes with exercise to provoke symptoms of FDEIA. This is the first report of a synergistic effect of aspirin in inducing urticaria/anaphylaxis, which was confirmed using challenge tests in patients with FDEIA.

Measurement of personal exposure to aerosols of Nephrops norvegicus (scampi) using a monoclonal-based assay

BACKGROUND

The industrial processing of scampi (Nephrops norvegicus) generates bioaerosols which can cause occupational respiratory disease in exposed individuals. The objective of this study was to develop a monoclonal antibody-based immunoassay to measure scampi proteins collected using standard personal air sampling methods.

METHODS

A monoclonal antibody was generated which predominantly bound to a single 97 Kd scampi protein, which we have shown to be a major allergen. This protein was shown by SDS PAGE immunoblotting to be present in various aqueous extracts from wastes produced during scampi processing. A quantitative immunoslotblot method was developed to quantify scampi from air sample filters.

RESULTS

We demonstrated the utility of this method by showing a significant difference (P = 0.015) in the level of exposure of two groups of 12 workers processing scampi at a traditional open workstation (GM = 607 ng m(-3)) and at an enclosed workstation (GM = 451 ng m(-3)).

CONCLUSION

We conclude that this assay can be used, in conjunction with health surveillance, to monitor exposure and the efficacy of measures to reduce exposure to airborne scampi allergen in an occupational environment.

The relevance of specific serum IgG, IgG4 and IgE in the determination of shrimp and crab allergies in Malaysian allergic rhinitis patients

The significance of food specific serum IgG4 antibody in food allergy is unclear and this led us to investigate the relevance of specific IgG4, along with IgG and IgE antibodies to two common food allergens in Malaysia. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum antibodies in 143 allergic rhinitis patients' sera, of which 47 were from patients with clinical indication of shrimp allergy, 46 with clinical indication of crab allergy and 50 without indication to either allergy. Clinical indication of allergy was based on answers to a questionnaire or results of the skin prick test. We found that the elevation of specific IgE or IgG4 is associated with shrimp and crab allergies but elevation of specific IgG is not associated with either allergy. However, the clinical utility of elevated specific IgG and IgG4 levels is pending further investigation.

Food anaphylaxis

Food anaphylaxis is now the leading single cause of anaphylactic reactions treated in emergency departments in Westernized countries. In the US, it is estimated that there are 29,000 anaphylactic reactions to foods treated in emergency departments and 125-150 deaths each year. Peanuts, tree nuts, fish and shellfish account for the vast majority of severe food anaphylactic reactions. Immunopathogenic mechanisms responsible for food anaphylaxis may differ somewhat from other forms of anaphylaxis, since elevation of serum tryptase is rarely seen following food anaphylactic reactions. Education regarding the strict avoidance of food allergens, the early recognition of anaphylactic symptoms, and the early use of self-injectable epinephrine remain the mainstays of therapy. However, clinical trials are now underway for the treatment of patients with peanut anaphylaxis utilizing anti-IgE antibody therapy and novel immunomodulatory therapies utilizing 'engineered' recombinant proteins, overlapping peptides, and immunostimulatory deoxyoligonucleotide sequences are being tested in animal models of anaphylaxis.

[Neurological features after consumption of a variety of neo-caledonian shellfish]

A few days after a seafood meal a patient suffered ataxia and stupor. His examination revealed a confused patient with cerebellar signs and ocular disturbances (hypotropia). Blood results, cerebrospinal fluid and brain CT scan were unremarkable. The patient developed a septic shock and died 4 weeks after admission. No necropsy was performed. Questioning his family confirmed that he had eaten a shellfish meal a few hours before onset of the digestive signs. Trocas (Tectus pyramis) were definitely identified. The clinical picture strongly suggested a seafood poisoning, namely ciguatera. However, no toxicologic assay was performed. To our knowledge, this poisoning has never been reported with trocas. Nevertheless, the feeding habits of trocas would suggest similarity with ciguatera poisoning.

[Allergy to squid and acari in a child]

Anaphylactic reactions after consumption of squid by patients sensitized to house dust mites have been reported several times.

CASE REPORT

A child allergic to dust mites developed an angioneurotic edema after eating squid. An immunoallergological assessment, including the prick test, labial test and IgE RAST revealed an allergy associated to both dust mites and squid.

CONCLUSIONS

In light of the potential seriousness of anaphylactic reactions, parents of children allergic to dust mites and these children should be made aware of the increased risk of allergies to squid that they may face.

Fish and shellfish poisoning

OBJECTIVE

To review history, biology, and medical aspects associated with fish and shellfish poisoning.

DATA SOURCES

Current literature, various Web sites, and Halstead's Volume II of Poisonous and Venomous Marine Animals.

STUDY SELECTION

Determined by author.

DATA SELECTION

Determined by author.

DATA SYNTHESIS

Fish and shellfish poisoning occur through the natural event of the food chain. Fish and shellfish consume algae that contain toxin-producing dinoflagellates. As a result they become contaminated and the toxin is concentrated as it moves up the food chain. Fish and shellfish can tolerate high levels of toxins, thereby appearing healthy while posing a significant danger to man. The toxin cannot be detected by sight, smell, or taste and is not destroyed by cooking or freezing. Thus man becomes an unsuspecting victim. There are several types of poisoning that occur through fish and shellfish consumption. They are ciguatera and scombroid fish poisoning; and paralytic, diarrheic, neurotoxic, and amnesic shellfish poisoning. A different toxin produces each of these poisonings; however, sources and symptoms may be similar among these poisonings making them difficult to diagnose. These intoxications can vary in severity from mild to fatal depending on the type and amount of toxin ingested. Age and underlying illnesses may also contribute to the outcome of these poisonings.

CONCLUSION

Though people are aware of health warnings and may think they are important, it is human nature to think that "this could not possibly happen to me". Therefore, they fail to make the necessary changes required to reduce the incidence of fish and shellfish poisoning.

Clinical infections of Vibrio vulnificus: a case report and review of the literature

Vibrio vulnificus is a marine Gram-negative bacillus that is recognized as a cause of fulminant primary septicemia and wound infections. One of the most common bacteria in seawater, V. vulnificus is concentrated in ocean filter feeders (e.g., oysters and clams). Primary septicemia can occur in patients, typically with underlying liver disease, who have acquired the organism through the gastrointestinal tract after recent consumption of raw shellfish. Characterized by fevers, chills, and bullous skin lesions, V. vulnificus septicemia is associated with a mortality greater than 50%. With septic shock, mortality approaches 100%. Wound infections are seen after injury to the skin in a marine environment or from exposure of preexisting wounds to seawater. Because of the high morbidity and mortality associated with V. vulnificus infections, effective treatment includes preventive measures to educate high-risk individuals, early search for and recognition of the disease, aggressive antibiotic therapy, supportive care, and, in the case of wound infections, aggressive debridement. Review of this subject was prompted by a case of V. vulnificus primary septicemia and fulminant septic shock in a patient with the unusual presentation of pain in the lower extremities.

An outbreak of Norwalk virus gastroenteritis following consumption of oysters

In August 1996, an outbreak of Norwalk virus gastroenteritis occurred among south-east Queensland and northern New South Wales residents over a four week period. Ninety-two of the 97 cases detected were confirmed as having consumed raw oysters within three days prior to developing the illness. No other food items or beverages were significantly associated with the illness. Environmental investigations indicated the Terranora Broadwater, Tweed Heads as the origin of the contaminated oysters. However, the primary source of Norwalk virus could not be verified. Oysters and other shellfish appear to be a common vehicle for transmission of this virus. This outbreak and the more recent hepatitis A outbreak associated with Wallis Lake oysters, highlight the susceptibility of oysters to environmental contamination and the urgent need for stricter quality control procedures. This report details the epidemiological, microbiological and environmental findings from an outbreak investigation conducted jointly by the Queensland and New South Wales health authorities.

[Allergy to shrimp. A contribution to reactions after ingestion of seafood and fishes]

Adverse reactions to seafood are common and may cause many types of symptoms that are difficult to define. The nature of these reactions are variable including allergic and toxic reactions as well as infectious diseases. The differentiation between these entities is essential in choosing therapy. We describe 9 patients with IgE mediated allergic reactions due to crustaceans and fish diagnosed from case history, clinical findings, skin tests and specific IgE antibodies. Most symptoms of a IgE mediated allergic reaction appear within 30 minutes after ingestion. Characteristics clinical features may include an urticarial rash, gastrointestinal symptoms and even anaphylaxis. In this case immediate therapy with intravenous glucocorticoids, antihistamine and perhaps subcutaneous epinephrine is required.

Sensitization to Anisakis simplex: an unusual presentation

It has recently been published patients suffering from urticaria or anaphylaxia induced by nematodes usually parasitizing fishs or cephalopode, in whom, Anisakis simplex (AK) sensitization prevalence was detected up to 37%. We tried out a prospective study to evaluate the presence of AK specific-IgE in an asthmatic population, comparing to other group of patients with urticaria. Complaints related to food ingestion were recorded in both, and dietetic measures were advised. Thirteen patients (13/66; 20%) showed AK specific IgE. Nine of them were asthmatics (p < 0.01), and only 4 suffered from urticaria. Four patients, three of them asthmatics, could link symptoms after fishs, cephalopode or, surprisingly, seafood intake, including epigastralgia, rhinorrhea, conjunctivitis, hives, and dyspnea. Atopia was not a consistent status, only five AK sensitized patients also did to common inhalants (all skin prick-test positive to house dust mites). Asthmatic AK-sensitized patients were older than non AK-sensitized asthmatics (46.23 vs 30.1; p < 0.05). The way of sensitization could be inhalative or through digestive mucosa parasitization by live larvae. Possibility that an AK allergen can play a role in adult asthma, should be considered specially in countries with high fish or seafood diet content.

Failure of cooking to prevent shellfish-associated viral gastroenteritis

BACKGROUND

In January 1995, Florida experienced the largest outbreak of oyster-associated gastroenteritis ever reported.

METHODS

We interviewed both the cohort of persons from 38 gatherings where illness was reported and a sample of harvesters and harvest-area residents. Oysters were traced by means of tags and dealer records, and water quality measures in harvest areas were reviewed. We examined stool specimens for small round structured viruses by means of electron microscopy and amplification of RNA by reverse-transcriptase polymerase chain reaction. We also tested serum specimens for antibodies to Norwalk virus.

RESULTS

Of 223 oyster eaters, 58% (129/223) became ill, compared with 3% (2/76) of non-oyster eaters (relative risk, 22; 95% confidence interval, 5.6-87.0). Most oyster eaters (67% [149/223]) ate only cooked (grilled, stewed, or fried) oysters. Oyster eaters who reported eating only thoroughly cooked oysters were as likely to become ill as those who ate raw oysters (relative risk, 0.68; 95% confidence interval, 0.45-1.0; P = .1). In 29 clusters, implicated oysters were from Apalachicola Bay, Florida. A community outbreak occurred in 2 bayside communities before the oyster harvest, leading to an increase in the reportedly common practice of overboard dumping of feces. Small round structured viruses were identified in the stool specimens of 2 harvest-area residents and 9 persons from 8 clusters. Results of water quality tests for fecal coliforms were within acceptable limits.

CONCLUSIONS

This large outbreak of gastroenteritis associated with oysters may have resulted from overboard dumping of feces during a community outbreak of diarrheal illness. Our findings of acceptable water quality measures for fecal contamination and the lack of appreciable protective effect from cooking leave the consumer with no assurance of safety.