The magnitude of severe box jellyfish cases on Koh Samui and Koh Pha-ngan in the Gulf of Thailand

Relationship between skin and body condition in three species of baleen whales

The assessment of free-ranging cetacean health through the study of skin conditions using photographs has gained prominence in recent years. However, little attention has been given to the relationships between cetacean skin conditions, species, and body condition. To explore this relationship among baleen whale species along the northwestern coast of Spain, we employed a non-invasive method involving photograph analysis. In this study, we examined skin conditions (including injuries, epizoites and ectoparasites, pigmentation disorders, skin lesions, and anatomical malformations) and body condition (overall physical contours and form, as an indicator of nutritional status and health) in 3 species of whales (blue, fin, and minke whales). This methodology facilitated the identification of 29 subcategories of distinct skin conditions and an assessment of body condition over a 5 yr period (2017 to 2021). In our study, we present evidence linking hypopigmentation, protruding pieces of tissue, and tattoo-like lesions to 'Poor' body condition in the 3 baleen whale species. Fin whales exhibited a higher susceptibility to mottling (prevalence = 17.7%), while blue whales were more prone to starbursts (prevalence = 90.5%). Additionally, we found a significant relationship between skin condition diversity and individual body condition. Our findings contribute valuable information to the broader understanding of the health status of baleen whales. Further investigations are necessary to delve into the etiology of the documented skin conditions and their potential implications for individual survival. This study serves as a foundation for ongoing research aimed at advancing our comprehension of these findings.

Insights into the discovery and intervention of metalloproteinase in marine hazardous jellyfish

The proliferation of toxic organisms caused by changes in the marine environment, coupled with the rising human activities along the coastal lines, has resulted in an increasing number of stinging incidents, posing a serious threat to public health. Here, we evaluated the systemic toxicity of the venom in jellyfish Chrysaora quinquecirrha at both cellular and animal levels, and found that jellyfish tentacle extract (TE) has strong lethality accompanied by abnormal elevation of blood biochemical indicators and pathological changes. Joint analysis of transcriptome and proteome indicated that metalloproteinases are the predominant toxins in jellyfish. Specially, two key metalloproteinases DN6695_c0_g3 and DN8184_c0_g7 were identified by mass spectrometry of the red blood cell membrane and tetracycline hydrochloride (Tch) inhibition models. Structurally, molecular docking and kinetic analysis are employed and observed that Tch could inhibit the enzyme activity by binding to the hydrophobic pocket of the catalytic center. In this study, we demonstrated that Tch impedes the metalloproteinase activity thereby reducing the lethal effect of jellyfish, which suggests a potential strategy for combating the health threat of marine toxic jellyfish.

The Dermatological Effects of Box Jellyfish Envenomation in Stinging Victims in Thailand: Underestimated Severity

INTRODUCTION

The dermatological effects of box jellyfish envenomation among stinging victims in Thailand are not well reported, particularly concerning chronic effects. For first aid, different recommendations indicate the necessity for the removal of tentacles in life-threatening situations. This study aimed to describe the dermatological effects of box jellyfish envenomation and propose recommendations regarding first aid for victims in urgent care or life-threatening situations.

METHODS

Surveillance systems and Toxic Jellyfish Networks were established to improve detection and investigation. The networks investigated all severe victims of jellyfish envenomation. A retrospective study was conducted, and victims of stinging by box jellyfish investigated from 1999 to 2021 were included.

RESULTS

One hundred and twenty-four victims were recorded. The majority of victims were males (55%), tourists (69%), and Thai nationals (49%). Direct contact had more severe consequences than indirect contact. Dermatological effects included edema, erythematous caterpillar track-like rash, blistering, bullae, papular eruption, necrosis, digital gangrene, recurrent dermatitis, dermal hypersensitivity, numbness, lichenification, hyperpigmentation, keloids, and scarring. Suffering and healing continued from several weeks to many years. Victims with multiple-tentacle box jellyfish stings had papular eruptions and greater severity of skin issues. All fatally envenomed victims collapsed within a few minutes and received incorrect/no first aid. The proposed first aid for life-threatening box jellyfish stings is continuous irrigation of the wound with vinegar for at least 30 s and initiation of cardiopulmonary resuscitation if there is no respiration or heartbeat. Tentacles often detach spontaneously, and removal is not always necessary, thus saving time.

CONCLUSIONS

The findings provide input for improving diagnosis and treatment guidelines.

Differences in clinical manifestations between cases stung by single-tentacle and multiple-tentacle box jellyfish over two decades

There are no routine laboratory investigations to identify jellyfish species and toxins in Thailand. Distinguishing clinical manifestation is important for medical care and also recommendations for the population. This study aimed to describe the clinical manifestations of box jellyfish stinging cases and determine differences between cases stung by single- (SBJ) and multiple-tentacle box jellyfish (MBJ). This retrospective study was conducted in Thailand. Data regarding injuries and deaths eligible for inclusion were those pertinent to stinging by box jellyfish under the National Surveillance System of Injuries and Deaths Caused by Toxic Jellyfish. All cases detected by the Toxic Jellyfish Networks were investigated. There were 29 SBJ, 92 MBJ, and 3 SBJ/or MBJ cases in the period 1999 to 2021. In about half of the cases in each group had abnormal heart rates and about one-third had respiratory distress. The SBJ group had a high proportion of pain in the other parts of the body (38.2%), abdominal cramps (13.8%), fatigue (24.1%), anxiety/agitation (24.1%), and there was no death. The MBJ group had a high proportion of severe pain and severe burning pain at the site of the wounds (44.3%), swelling/edema at the affected organs/areas (46.8%), collapse/near-collapse (30.4%), worse outcomes (9.8%), and 9.8% deaths. In comparison to the MBJ group, the SBJ group were 13.4 times (95% Confidence Intervals of Relative Risk: 4.9, 36.6) and 6.1 times (1.2, 31.4) more likely to have pain in other parts of the body and abdominal cramps, subsequently. MBJ group was 1.8 times (1.4, 2.2) more likely to have pain at wounds than the SBJ group. Some initial symptoms might make health professionals misdiagnose SBJ as MBJ stinging. The Irukandji-like syndrome that appeared later among SBJ cases is the clue for correct diagnosis. These results are useful for the improvement of diagnosis, medical care, and surveillance.

Raising Awareness on the Clinical and Forensic Aspects of Jellyfish Stings: A Worldwide Increasing Threat

Jellyfish are ubiquitous animals registering a high and increasing number of contacts with humans in coastal areas. These encounters result in a multitude of symptoms, ranging from mild erythema to death. This work aims to review the state-of-the-art regarding pathophysiology, diagnosis, treatment, and relevant clinical and forensic aspects of jellyfish stings. There are three major classes of jellyfish, causing various clinical scenarios. Most envenomations result in an erythematous lesion with morphological characteristics that may help identify the class of jellyfish responsible. In rare cases, the sting may result in delayed, persistent, or systemic symptoms. Lethal encounters have been described, but most of those cases happened in the Indo-Pacific region, where cubozoans, the deadliest jellyfish class, can be found. The diagnosis is mostly clinical but can be aided by dermoscopy, skin scrapings/sticky tape, confocal reflectance microscopy, immunological essays, among others. Treatment is currently based on preventing further envenomation, inactivating the venom, and alleviating local and systemic symptoms. However, the strategy used to achieve these effects remains under debate. Only one antivenom is currently used and covers merely one species (Chironex fleckeri). Other antivenoms have been produced experimentally but were not tested on human envenomation settings. The increased number of cases, especially due to climate changes, justifies further research in the study of clinical aspects of jellyfish envenoming.

Rapid and Accurate Species-Specific PCR for the Identification of Lethal Chironex Box Jellyfish in Thailand

Box jellyfish are extremely potent venom-producing marine organisms. While they have been found worldwide, the highest health burden has been anticipated to be the tropical Indo-Pacific of Southeast Asia (SEA). At least 12 Cubozoan species have now been documented in Thai waters, and many of them inflict acutely lethal strings, especially those under the order Chirodropida. Our previous study has successfully differentiated species of box jellyfish using DNA sequencing to support the morphological study. In this study, we specifically designed polymerase chain reaction (PCR) primers for the 16S ribosomal RNA (rRNA) gene and the mitochondrial DNA cytochrome oxidase subunit I (COI) gene of lethal Thai Chironex species. The SYBR green-based real-time PCR panel was performed for rapid species identification. The sensitivity and specificity of the panel were determined by testing samples of different species. Moreover, we applied the panel to the tentacle sample from a real patient, which helped confirm the animal-of-cause of envenomation. Our results show a success for species identification of box jellyfish using 16S rRNA and COI PCR panel, which revealed congruence between molecular and morphological identification. Furthermore, the panel worked very well with the unknown samples and jellyfish tissue from the real envenomation case. The results demonstrated that molecular panels were able to identify three species of Chironex box jellyfish both rapidly and accurately, and can be performed without having a complete specimen or morphological study.

Delayed deep dermal necrosis after jellyfish sting in a 4-year-old female infant

We report the case of a 4-year-old female infant who developed ongoing deep dermal necrosis of the bilateral legs after jellyfish contact in Thailand. Stepwise radical debridement and vacuum assisted wound therapy seemed to be an effective strategy to prevent progressive soft tissue loss.

Cnidarian Jellyfish: Ecological Aspects, Nematocyst Isolation, and Treatment Methods of Sting

Cnidarians play an important role in ecosystem functioning, in the competition among species, and for possible utilization of several active compounds against cardiovascular, nervous, endocrine, immune, infective, and inflammatory disorders or having antitumoral properties, which have been extracted from these organisms. Nevertheless, notwithstanding these promising features, the main reason for which cnidarians are known is due to their venomousness as they have a serious impact on public health as well as in economy being able to affect some human activities. For this reason a preeminent subject of the research about cnidarians is the organization of proper systems and methods of care and treatment of stinging. This chapter aims to present the data about the morphological, ecological, toxicological, epidemiological, and therapeutic aspects regarding cnidarians with the purpose to summarize the existing knowledge and to stimulate future perspectives in the research on these organisms.

The public health impact of a new simple practical technique for collection and transfer of toxic jellyfish specimens and for nematocyst identification

Our team aimed to create a new, simple, and inexpensive technique for collecting and transferring of toxic jellyfish specimens and for nematocysts identification. We collected tentacles of Chironex spp., Morbakka spp., and Physalia spp., and transferred them from the beaches by standard and by 'vacuum sticky tape' (VST) techniques. For the VST technique, our team placed the sticky tape on a tentacle and then folded it over to seal the tentacle in the equivalent of a vacuum. We kept the VST in room temperature. For nematocyst identification, we placed the VST on a glass microscope slide and took photographs down the microscope's eye piece using a mobile phone camera. The image quality was as good as when produced by standard techniques. Different classes of toxic jellyfish could be identified. Thus, VST is a potential public health breakthrough because it is practical, durable, inexpensive, allows good discrimination. It enables early warning of danger to health and rapid response via social network.

Cubozoan Sting-Site Seawater Rinse, Scraping, and Ice Can Increase Venom Load: Upending Current First Aid Recommendations

Cnidarian envenomations are the leading cause of severe and lethal human sting injuries from marine life. The total amount of venom discharged into sting-site tissues, sometimes referred to as "venom load", has been previously shown to correlate with tentacle contact length and sequelae severity. Since <1% of cnidae discharge upon initial tentacle contact, effective and safe removal of adherent tentacles is of paramount importance in the management of life-threatening cubozoan stings. We evaluated whether common rinse solutions or scraping increased venom load as measured in a direct functional assay of venom activity (hemolysis). Scraping significantly increased hemolysis by increasing cnidae discharge. For Alatina alata, increases did not occur if the tentacles were first doused with vinegar or if heat was applied. However, in Chironex fleckeri, vinegar dousing and heat treatment were less effective, and the best outcomes occurred with the use of venom-inhibiting technologies (Sting No More® products). Seawater rinsing, considered a "no-harm" alternative, significantly increased venom load. The application of ice severely exacerbated A. alata stings, but had a less pronounced effect on C. fleckeri stings, while heat application markedly reduced hemolysis for both species. Our results do not support scraping or seawater rinsing to remove adherent tentacles.