Use of intravenous lipid emulsion therapy as a novel treatment for brevetoxicosis in sea turtles.

The southwest coast of Florida experiences annual red tides, a type of harmful algal bloom that results from high concentrations of Karenia brevis. These dinoflagellates release lipophilic neurotoxins, known as brevetoxins, that bind to sodium channels and inhibit their inactivation, resulting in a variety of symptoms that can lead to mass sea turtle strandings. Traditional therapies for brevetoxicosis include standard and supportive care (SSC) and/or dehydration therapy; however, these treatments are slow-acting and often ineffective. Because red tide events occur annually in Florida, our objective was to test intravenous lipid emulsion (ILE) as a rapid treatment for brevetoxicosis in sea turtles and examine potential impacts on toxin clearance rates, symptom reduction, rehabilitation time, and survival rates. Sea turtles exhibiting neurological symptoms related to brevetoxicosis were brought to rehabilitation from 2018-2019. Upon admission, blood samples were collected, followed by immediate administration of 25 mg ILE/kg body mass (Intralipid® 20%) at 1 mL/min using infusion pumps. Blood samples were collected at numerous intervals post-ILE delivery and analyzed for brevetoxins using enzyme-linked immunosorbent assays. In total, nine (four subadults, one adult female, four adult males) loggerheads (Caretta caretta), five (four juvenile, one adult female) Kemp's ridleys (Lepidochelys kempii), and four juvenile green turtles (Chelonia mydas) were included in this study. We found that plasma brevetoxins declined faster compared to turtles that received only SSC. Additionally, survival rate of these patients was 94% (17/18), which is significantly higher than previous studies that used SSC and/or dehydration therapy (47%; 46/99). Nearly all symptoms were eliminated within 24-48 h, whereas using SSC, symptom elimination could take up to seven days or more. The dosage given here (25 mg/kg) was sufficient for turtles in this study, but the use of a higher dosage (50-100 mg/kg) for those animals experiencing severe symptoms may be considered. These types of fast-acting treatment plans are necessary for rehabilitation facilities that are already resource-limited. Intravenous lipid emulsion therapy has the potential to reduce rehabilitation time, save resources, and increase survival of sea turtles and other marine animals experiencing brevetoxicosis.

Scombroid poisoning secondary to tuna ingestion: a case report / [Intoxicación escombroide secundaria al consumo de atún: presentación de un caso].

Scombroid poisoning is caused by the consumption of certain types of fish (from the Scombridae family), especially tuna. Due to inadequate refrigeration procedures, these fish have high levels of histamine which generate symptoms similar to those of a food allergy in their consumers, so it is frequently underdiagnosed. It is self-limited in a few hours and the symptoms are usually not serious, except for specific cases reported in the literature of hypotension, bronchospasm, respiratory distress, tachyarrhythmias, and even acute myocardial infarction. We report here the case of a woman admitted to the emergency department of a third level hospital in Medellín a few minutes after eating tuna with the typical symptoms of intoxication, as well as tachyarrhythmias, a serious and atypical manifestation.

La intoxicación escombroide es ocasionada por el consumo de ciertos tipos de pescado (de la familia Scombridae), comúnmente el atún, los cuales acumulan grandes concentraciones de histamina cuando los procedimientos de refrigeración son inadecuados, ocasionando en quienes los consumen síntomas muy similares a los de una alergia alimentaria, por lo que es frecuente que no se diagnostique correctamente. Generalmente, los síntomas desaparecen en pocas horas y no suelen ser graves, excepto algunos casos descritos en la literatura especializada, de hipotensión, broncoespasmo, dificultad respiratoria, taquicardia supraventricular e, incluso, infarto agudo de miocardio. Este fue, precisamente, el caso de una mujer que ingresó al servicio de urgencias de un hospital de tercer nivel de Medellín a los pocos minutos de haber ingerido atún con una sintomatología típica de la intoxicación, pero con taquicardia supraventricular, una de sus manifestaciones graves y atípicas.

[Scombroid food poisoning among hospital personnel]. / Scombroïde-intoxicatie onder ziekenhuispersoneel.

BACKGROUND: Scombroid food poisoning is caused by eating fish with a high concentration of histamine. Histamine is converted from histidine in fish of the Scombroidea family if it is not stored at a sufficiently low temperature. The clinical picture resembles an allergic reaction. CASE DESCRIPTION: Twenty-one of our hospital personnel went to the ER, mostly reporting flushing, headache, palpitations and gastro-intestinal symptoms. They had all eaten tuna salad in the staff canteen. The symptoms appeared to be caused by scombroid food poisoning. CONCLUSION: As a result of early recognition of the clinical picture and prompt crisis management we were able to prevent the outbreak spreading further.

Investigating the gene expression profiles of rehabilitated Florida manatees (Trichechus manatus latirostris) following red tide exposure.

To investigate a Florida manatee (Trichechus manatus latirostris) mortality event following a red tide bloom in Southwest Florida, an RNA sequencing experiment was conducted. Gene expression changes in white blood cells were assessed in manatees rescued from a red tide affected area (n = 4) and a control group (n = 7) using RNA sequencing. The genes with the largest fold changes were compared between the two groups to identify molecular pathways related to cellular and disease processes. In total, 591 genes (false discovery rate <0.05) were differentially expressed in the red tide group. Of these, 158 were upregulated and 433 were downregulated. This suggests major changes in white blood cell composition following an exposure to red tide. The most highly upregulated gene, Osteoclast associated 2C immunoglobulin-like receptor (OSCAR), was upregulated 12-fold. This gene is involved in initiating the immune response and maintaining a role in adaptive and innate immunity. The most highly downregulated gene, Piccolo presynaptic cytomatrix protein (PCLO), was downregulated by a factor of 977-fold. This gene is associated with cognitive functioning and neurotransmitter release. Downregulation of this gene in other studies was associated with neuronal loss and neuron synapse dysfunction. Among the cellular pathways that were most affected, immune response, including inflammation, wounds and injuries, cell proliferation, and apoptosis were the most predominant. The pathway with the most differentially expressed genes was the immune response pathway with 98 genes involved, many of them downregulated. Assessing the changes in gene expression associated with red tide exposure enhances our understanding of manatee immune response to the red tide toxins and will aid in the development of red tide biomarkers.

Identification and management of marine envenomations in pediatric patients

Marine envenomations can cause a diverse array of clinical syndromes. Systemic and life-threatening reactions, as well as delayed presentations, can occur. The pediatric population is at higher risk for serious reactions to envenomations because their greater body surface area and smaller body mass can lead to a higher relative venom load. Although the majority of the literature on marine envenomations is of low quality, the available literature does suggest that management varies depending on the geographic location. This issue reviews both common and life-threatening presentations of marine envenomations, highlights key aspects of the history and physical examination that will help narrow the differential, and offers recommendations for management based on the envenomating creature and geographic location.

Fluorescent immunoliposomal nanovesicles for rapid multi-well immuno-biosensing of histamine in fish samples.

Scombroid poisoning in fish-based and other food products has raised concerns due to toxicity outbreaks and incidences associated with histamine, thus measuring the amount of histamine toxic molecule is considered crucial quality indicator of food safety and human health. In this study, liposome-based measurement of histamine was performed via rupturing mechanism of sulforhodamine B dye encapsulated anti-histamine antibody conjugated liposomal nanovesicles. The immunosensing ability of immuno-liposomal format was assessed by monitoring the fluorescence at excitation/emission wavelength of 550/585 nm. Immuno-liposomal format assays were considered, one based on single wash procedure (Method 1), which had a detection limit of 10 ppb and quantification limit 15-80 ppb. While Method 2 based on one-by-one wash procedure had a detection limit of 2-3 ppb and quantification limit 8.5 ppb-200 ppm that required 2 h 30 min to perform. In view of better quantification limit, Method 2 was chosen for further tests required to validate its applicability in real samples. The feasibility of Method 2 was reconfirmed in fresh mackerel fish, and canned fish (tuna and salmon) with a similar detection limits but with low amplified fluorescence signals and sufficient levels of histamine recovery from fresh mackerel (73.50-99.98%), canned tuna (79.08-103.74%) and salmon (74.56-99.02%). The specificity and method accuracy were expressed as % CV in the range 5.34%-8.48%. Overall, the developed multi-well sensing system (Method 2) showed satisfactory specificity, cost effectiveness, rapidity, and stability for monitoring histamine toxicity as a practical food diagnostic device.

A diver's guide to subaquatic envenomation in the Mediterranean.

INTRODUCTION: Between 40,000 and 50,000 divers and swimmers are envenomated each year and diving as a hobby is becoming increasingly popular. In the Mediterranean, envenomation is most often by Weever fish, Scorpion fish and jellyfish but coral and sea urchins may also be venomous. ENVENOMATION: Most stings cause local inflammation, oedema and pain. The severity of pain varies with the venom and the amount injected. In severe cases, stings may be life-threatening due to cardiogenic or anaphylactic shock or penetration of vital structures. MANAGEMENT: Most cases of envenomation are preventable with a combination of measures including the avoidance of contact through good buoyancy control, the wearing of body-suits, and by maintaining visual awareness. Immediate management is to return to the surface, elevate and wash the site of injury. Immersion in hot water followed by simple analgesics for pain relief has been shown to be more effective than other methods. More severe cases should be identified by symptoms including confusion and heavy bleeding and referred to qualified medical care. CONCLUSION: Envenomation by subaquatic species is common and preventable yet the dissemination of the appropriate knowledge is limited. This knowledge summary provides pertinent information aimed at divers in preventing and managing such injuries.

Global geographical and historical overview of cyanotoxin distribution and cyanobacterial poisonings.

Cyanobacteria are photoautotrophic organisms which occur in aquatic and terrestrial environments. They have the potential to produce toxins which pose a threat to human and animal health. This review covers the global distribution of the common cyanotoxins and related poisoning cases. A total of 468 selected articles on toxic cyanobacteria, dating from the earliest records until 2018, were reviewed. Most of the articles were published after 2000 (72%; 337 out of 468), which is consistent with the recent growth in interest in the analysis, toxinology and ecotoxicology of cyanotoxins. Animal and/or human poisoning cases were described in more than a third of the overall publications (38%; 177 out of 468). The reviewed publications showed that there were 1118 recorded identifications of major cyanotoxins in 869 freshwater ecosystems from 66 countries throughout the world. Microcystins were the most often recorded cyanotoxins worldwide (63%; 699 out of 1118), followed by cylindrospermopsin (10%; 107 out of 1118), anatoxins (9%; 100 out of 1118), and saxitoxins (8%; 93 out of 1118). Nodularins were the most rarely recorded cyanotoxins (2%; 19 out of 1118); however, there were also reports where cyanotoxins were not analysed or specified (9%; 100 out of 1118). The most commonly found toxic cyanobacterial genera were Microcystis spp. (669 reports), Anabaena spp. (397 reports), Aphanizomenon spp. (100 reports), Planktothrix spp. (98 reports), and Oscillatoria spp. (75 reports). Furthermore, there were 183 recorded cyanotoxin poisonings of humans and/or animals. Out of all toxic cyanobacterial blooms reviewed in this paper, the highest percentage of associated poisonings was found in North and Central America (39%; 69 cases out of 179), then Europe (20%; 35 out of 179), Australia including New Zealand (15%; 27 out of 179), and Africa (11%; 20 out of 179), while the lowest percentage was related to Asia (8%; 14 cases out of 179) and South America (8%; 14 cases out of 179). Events where only animals were known to have been affected were 63% (114 out of 182), whereas 32% (58 out of 182) of the investigated events involved only humans. A historical overview of human and animal poisoning episodes associated with cyanobacterial blooms is presented. Further, geographical data on the occurrence of cyanotoxins and related poisonings based on the available literature are shown. Some countries (mainly European) have done very intensive research on the occurrence of toxic cyanobacteria and cyanotoxins, and reported related ecotoxicological observations, while in some countries the lack of data is apparent. The true global extent of cyanotoxins and associated poisonings is likely to be greater than found in the available literature, and it can be assumed that ecotoxicological and hygienic problems caused by toxic cyanobacteria may occur in more environments.

South African Marine Envenomations and Poisonings as Managed Telephonically by the Tygerberg Poisons Information Centre: A 20-Year Retrospective Review.

INTRODUCTION: South Africa has an abundance of marine life, and the potential for hazardous exposure to marine life is high. To our knowledge, this is the first epidemiological review regarding marine toxicity that has ever been conducted in sub-Saharan Africa. The aim of this review was to investigate marine toxicology data as managed telephonically by the Tygerberg Poisons Information Centre. METHODS: Marine toxicology cases were retrospectively analyzed for a 20-y period (January 1, 1995 to December 31, 2014). Data were extracted from archived consultation forms. Descriptive statistics are presented, and post hoc analyses compared age, sex, province, and caller's background with severity and type of toxicology. RESULTS: A total of 311 calls involved 392 cases. Most calls involved adults (n=317, 81%) and males (n=214, 55%) and presented with no or minor symptoms (n=242, 62%). Poisoning from ingestion (n=239; 61%) was more commonly encountered than was marine envenomation (n=153; 39%), with paralytic shellfish poisoning (n=118; 30%), scombroid poisoning (n=93; 24%), and envenomation from stingrays (n=36; 9%) and bluebottles (n=33; 8%) occurring often. Healthcare professionals were more likely to consult for severe cases (odds ratio 3.3; 95% CI 1.9-5.9) and poisoning-related cases (odds ratio 1.8; 95% CI 1.1-2.9). CONCLUSION: The proportion of marine-related toxicology cases was low. Telephonic consultations by healthcare professionals relating to poisoning were generally of a serious nature. The data can be used to drive public health awareness campaigns.

Marine toxins and nephrotoxicity:Mechanism of injury.

Marine toxins are known among several causes of toxin induced renal injury. Enzymatic mechanism by phospholipase A2 is responsible for acute kidney injury (AKI) in sea snake envenoming without any change in cardiac output and systemic vascular resistance. Cnidarian toxins form pores in the cell membrane with Ca influx storm resulting in cell death. Among plankton toxins domoic acid, palytoxin and maitotoxin cause renal injury by ion transport into the cell through ion channels resulting in renal cell swelling and lysis. Okadaic acid, calyculin A, microcystin LR and nodularin cause AKI by serine threonine phosphatase inhibition and hyperphosphorylation with increased activity of Ca2+/calmodulin - dependent protein kinase II, increased cytosolic Ca2+, reactive oxygen species, caspase and P53. Renal injury by plankons is mostly subclinical and requires sensitive biomarker for diagnosis. In this respect repeated consumption of plankton toxin contaminated seafood is a risk of developing chronic renal disease. The subject deserves more clinical study and scientific attention.

Food poisoning caused by scombroids: A case-control study.

The aim of this study is to report the epidemiological characteristics of a food poisoning outbreak due to scombroid fish in a hospital. A case-control study (1:4) was conducted. Patients either symptomatic of food poisoning (cases) or asymptomatic (controls) eating at the hospital cafeteria were included. To identify the source of the outbreak, sanitary control factors were assessed. Microbiological studies and the mast cell tryptase test were performed. All cases and controls received a questionnaire enquiring about symptoms and foods consumed. The odds ratios (OR) for all risk factors and their 95% confidence intervals (CI) were assessed. In total, 20 individuals (90% female) were included in the study: four cases and 16 controls. The overall mean age was 43 years (SD: 10.2). The most frequent symptom observed was facial and neck erythaema (100%). Microbiological cultures were negative, the mast cell tryptase test was normal and breakdown of the cold chain did not occur. The most likely source of the outbreak was fried anchovies (OR: 34.7; 95% CI: 1.50-809.6; p=0.02). Methods suitable to the rapid assessment of the outbreak allowed us to establish prompt preventive measures and identify the likely aetiology.

Mixtures of Lipophilic Phycotoxins: Exposure Data and Toxicological Assessment.

Lipophilic phycotoxins are secondary metabolites produced by phytoplanktonic species. They accumulate in filter-feeding shellfish and can cause human intoxication. Regulatory limits have been set for individual toxins, and the toxicological features are well characterized for some of them. However, phycotoxin contamination is often a co-exposure phenomenon, and toxicological data regarding mixtures effects are very scarce. Moreover, the type and occurrence of phycotoxins can greatly vary from one region to another. This review aims at summarizing the knowledge on (i) multi-toxin occurrence by a comprehensive literature review and (ii) the toxicological assessment of mixture effects. A total of 79 publications was selected for co-exposure evaluation, and 44 of them were suitable for toxin ratio calculations. The main toxin mixtures featured okadaic acid in combination with pectenotoxin-2 or yessotoxin. Only a few toxicity studies dealing with co-exposure were published. In vivo studies did not report particular mixture effects, whereas in vitro studies showed synergistic or antagonistic effects. Based on the combinations that are the most reported, further investigations on mixture effects must be carried out.

A diagnostic red herring.

CLINICAL INTRODUCTION: A 29-year-old keen parachutist presented to the emergency services in Cyprus complaining of sudden-onset facial flushing, dizziness and a widespread rash. The episode began on a hot day, 1 hour after she had eaten a breakfast of tinned tuna, and while she was ascending in an aircraft to parachute from 10 000 ft. She completed her jump uneventfully. She had no significant medical history (figure 1).emermed;35/3/184/F1F1F1Figure 1Patient's legs on presentation; this rash was generalised. QUESTION: Based on the history and rash, which ONE of the following is the most likely diagnosis?Fish allergyHeat-related eruptionScombrotoxin poisoningStress-induced urticaria.

Marine Envenomation.

Venomous aquatic animals are hazardous to swimmers, surfers, divers, and fishermen. Exposures include mild stings, bites, abrasions, and lacerations. Severe envenomations can be life threatening. This article reviews common marine envenomations, exploring causative species, clinical presentation, and current treatment recommendations. Recommendations are included for cnidaria, sponges, bristle worms, crown-of-thorns starfish, sea urchins, venomous fish, stingrays, cone snails, stonefish, blue-ringed octopus, and sea snakes. Immediate and long-term treatment options and management of common sequelae are reviewed. Antivenom administration, treatment of anaphylaxis, and surgical indications are discussed.

Toxicology of microcystins with reference to cases of human intoxications and epidemiological investigations of exposures to cyanobacteria and cyanotoxins.

Blooms of cyanobacteria have been documented throughout history, all over the world. Mass populations of these organisms typically present hazards to human health and are known for the production of a wide range of highly toxic metabolites-cyanotoxins, of which among the most common and most investigated are the microcystins. The toxicity of the family of microcystin congeners to animal and cell models has received much attention; however, less is known about their negative effects on human health, whether via acute or chronic exposure. Useful information may be acquired through epidemiological studies since they can contribute to knowledge of the relationships between cyanotoxins and human health in environmental settings. The aim of this review is to compile and evaluate the available published reports and epidemiological investigations of human health incidents associated with exposure to mass populations of cyanobacteria from throughout the world and to identify the occurrence and likely role of microcystins in these events. After an initial screening of 134 publications, 42 publications (25 on the chronic and 17 on the acute effects of cyanotoxins) describing 33 cases of poisonings by cyanobacterial toxins in 11 countries were reviewed. The countries were Australia, China, Sri Lanka, Namibia, Serbia, Sweden, UK, Portugal, Brazil, USA, and Canada. At least 36 publications link cyanobacteria/cyanotoxins including microcystins to adverse human health effects. The studies were published between 1960 and 2016. Although the scattered epidemiological evidence does not provide a definitive conclusion, it can serve as additional information for the medical assessment of the role of microcystins in cancer development and other human health problems. This paper discusses the major cases of cyanotoxin poisonings as well as the strengths, weaknesses, and importance of the performed epidemiological research. This study also proposes some recommendations for future epidemiological work.

Acute and chronic dietary exposure to domoic acid in recreational harvesters: A survey of shellfish consumption behavior.

Domoic acid (DA) is a neurotoxin that is naturally produced by phytoplankton and accumulates in seafood during harmful algal blooms. As the prevalence of DA increases in the marine environment, there is a critical need to identify seafood consumers at risk of DA poisoning. DA exposure was estimated in recreational razor clam (Siliqua patula) harvesters to determine if exposures above current regulatory guidelines occur and/or if harvesters are chronically exposed to low levels of DA. Human consumption rates of razor clams were determined by distributing 1523 surveys to recreational razor clam harvesters in spring 2015 and winter 2016, in Washington, USA. These consumption rate data were combined with DA measurements in razor clams, collected by a state monitoring program, to estimate human DA exposure. Approximately 7% of total acute exposures calculated (including the same individuals at different times) exceeded the current regulatory reference dose (0.075mgDA·kgbodyweight-1·d-1) due to higher than previously reported consumption rates, lower bodyweights, and/or by consumption of clams at the upper range of legal DA levels (maximum 20mg·kg-1 wet weight for whole tissue). Three percent of survey respondents were potentially at risk of chronic DA exposure by consuming a minimum of 15 clams per month for at 12 consecutive months. These insights into DA consumption will provide an additional tool for razor clam fishery management.

Domoic Acid Poisoning as a Possible Cause of Seasonal Cetacean Mass Stranding Events in Tasmania, Australia.

The periodic trend to cetacean mass stranding events in the Australian island state of Tasmania remains unexplained. This article introduces the hypothesis that domoic acid poisoning may be a causative agent in these events. The hypothesis arises from the previously evidenced role of aeolian dust as a vector of iron input to the Southern Ocean; the role of iron enrichment in Pseudo-nitzschia bloom proliferation and domoic acid production; and importantly, the characteristic toxicosis of domoic acid poisoning in mammalian subjects leading to spatial navigation deficits. As a pre-requisite for quantitative evaluation, the plausibility of this hypothesis was considered through correlation analyses between historical monthly stranding event numbers, mean monthly chlorophyll concentration and average monthly atmospheric dust loading. Correlation of these variables, which under the domoic acid stranding scenario would be linked, revealed strong agreement (r = 0.80-0.87). We therefore advocate implementation of strategic quantitative investigation of the role of domoic acid in Tasmanian cetacean mass stranding events.