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The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

BugGuide.net is a website where arthropod photographs submitted by the public are identified by professional and amateur entomologists. In April 2023 posts containing "bitten" or "stung" were reviewed. Of 39 verified bites, 10 were blood-feeding insects. Others included 9 Heteroptera, 6 spiders, 6 lacewings. 110 posts of stings included 44 social Hymenoptera, 33 solitary Hymenoptera, 5 Heteroptera, 20 caterpillars and 4 scorpions. Injury from lacewing larvae, true bugs, solitary Hymenoptera and caterpillars was unexpectedly common., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Loxoscelism is a serious public health problem in Peru, with approximately 2500 accidents reported per year. To envision alternatives to cope with this health problem, the neutralizing humoral immune response against the lethal effects of Peruvian spider Loxosceles laeta venom was evaluated in a mouse model by immunization with a non-toxic multiepitopic protein (rMEPLox). This immunogen contains epitopes from an astacin-like metalloprotease, a hyaluronidase and a sphingomyelinase-D from Loxosceles intermedia and from SMase-I from L. laeta venoms. In vivo protection assays showed that five out of six mice immunized with rMEPLox (after six injections) resisted to 1.4 LD 50 of L. laeta venom, whereas only two animals from a control group survived. The present results indicates that this multiepitopic protein can be a promising candidate for anti-loxoscelic antivenom production and experimental vaccination approaches., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Antivenom is the only effective therapy for treating any envenomation. Despite its obvious public health importance, the laborious process of procuring, distributing and controlling the quality of such immunobiologicals is being neglected. Brazil is fully self-sufficient in the production of antivenoms. Since the 1950s, Loxoscelism, a syndrome with an onset after a spider bite from specimens of the Loxosceles genus occurs, is considered a public health issue. The Brazilian history in developing antivenom therapy, its production hindrances, and other challenges are discussed in this paper, as well as some promising novelties that can improve production and processing of Loxosceles antivenom., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Despite the popularity of theraphosids, detailed reports on bite symptoms are still limited to few geographic regions and subfamilies. We therefore examined 363 published bite reports and noticed muscles cramps caused by theraphosids from nearly all continents and subfamilies. Symptoms are mostly locally restricted and mild, but 12.7% of victims experience pronounced cramps with highest incidence rates by Poecilotheriinae, Harpactirinae and Stromatopelminae subfamilies. We discuss how variations in venom quantity correlate with muscle cramp prevalence., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The Loxosceles genus belongs to the Sicariidae family and it comprises species whose venom can cause accidents with potentially fatal consequences. We have previously shown that SMase D is the enzyme responsible for the main pathological effects of Loxosceles venom. Despite the severity of accidents with Loxosceles, few species are considered to be of medical importance. Little is known about the venom of non-synanthropic species that live in natural environments. To contribute to a better understanding about the venom's toxicity of Loxosceles genus, the aim of this study was to (i) characterize the toxic properties of Loxosceles amazonica from two different localities and a recent described cave species Loxosceles willianilsoni and (ii) compare these venoms with that from Loxosceles laeta, which is among the most toxic ones. We show here that both L. amazonica venoms (from the two studied locations) and L. willianilsoni presented SMase D activity similar to that exhibited by L. laeta venom. Although L. amazonica and L. willianilsoni venoms were able to induce complement dependent human erythrocytes lysis, they were not able to induce cell death of human keratinocytes, as promoted by L. laeta venom, in the concentrations tested. These results indicate that other species of Loxosceles, in addition to those classified as medically important, have toxic potential to cause accidents in humans, despite interspecific variations that denote possible less toxicity., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study was undertaken to elucidate why VEGF/VEGFR-2 is elevated in the hippocampus of rats injected with Phoneutria nigriventer spider venom (PNV). PNV delays Na + channels inactivation; blocks Ca 2+ and K + channels, increases glutamate release, causes blood-brain breakdown (BBBb), brain edema and severe excitotoxicity. Analytical FT-IR spectroscopy showed profound alteration in molecular biochemical state, with evidences for VEGFR-2 (KDR/Flk-1) signaling mediation. By blocking VEGF/VEGFR-2 binding via pre-treatment with itraconazole we demonstrated that animals' condition was deteriorated soon at 1-2 h post-PNV exposure concurrently with decreased expression of VEGF, BBB-associated proteins, ZO-1, β-catenin, laminin, P-gp (P-glycoprotein), Neu-N (neuron's viability marker) and MAPKphosphorylated-p38, while phosphorylated-ERK and Src pathways were increased. At 5 h and coinciding with incipient signs of animals' recuperation, the proteins associated with protection (HIF-1α, VEGF, VEGFR-1, VEGFR-2, Neu-N, occludin, β-catenin, laminin, P-gp efflux protein, phosphorylated-p38) increased thus indicating p38 pathway activation together with paracellular route strengthening. However, the BBB transcellular trafficking and caspase-3 increased (pro-apoptotic pathway activation). At 24 h, the transcellular route reestablished physiological state but the pro-survival pathway PI3K/(p-Akt) dropped in animals underwent VEGF/VEGFR-2 binding inhibition, whereas it was significantly activated at matched interval in PNV group without prior itraconazole; these results demonstrate impaired VEGF' survival effects at 24 h. The inhibition of VEGF/VEGFR-2 binding identified 5 h as turning point at which multi-level dynamic interplay was elicited to reverse hippocampal damage. Collectively, the data confirmed VEGFR-2 signaling via serine-threonine kinase Akt as neuroprotective pathway against PNV-induced damage. Further studies are needed to elucidate mechanisms underlying PNV effects., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Loxosceles spp. (Araneae, Sicariidae), known as brown spiders, are distributed in temperate and tropical regions worldwide. Accidents caused by these spiders are known as loxoscelism and constitute a public health problem, especially in Brazil. The present review describes the taxonomy, distribution, and ecological profile of brown spiders, as well as the molecular and biochemical aspects of Loxosceles venom. Additionally, it presents an overview on L. similis, a species found in the Southeastern region of Brazil. In this region, the number of Loxosceles accidents has been increasing in the past few years, thus calling attention to its raising importance as a medically relevant spider species in Brazil., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The public perception of spiders and scorpions is skewed towards the potential harm they can inflict in humans, despite recent scientific evidence that arachnid venom components might be useful as bioinsecticides or even human therapeutics. Nevertheless, arachnids are becoming more popular as pets in Europe, America and Asia, raising the question for regulatory agencies in these regions as to whether they need to take measurements to protect their citizens. In order to decide upon the necessary regulatory steps, they first need to determine which arachnids are actually dangerous to humans. This review therefore provides an overview of the current literature on verified bites and stings from spiders and scorpions with the aim of assessing their potential danger for human health. As a guideline, we also provide a list of those arachnid genera that we consider as potentially dangerous, which includes 10 spider and 11 scorpion genera. The arachnid genera classified as dangerous comprise less than a quarter of all extant scorpion species and only 0.5% of all spiders species, with the actual number most likely being much lower than that, as not all species in those genera might turn out to pose an actual threat for humans. In conclusion, we found that only a small percentage of scorpions and a minute percentage of all spiders can be considered as potentially dangerous to humans. While in some countries of origin the high incidence of envenomations by dangerous arachnids can result in a serious problem to the health system, we assessed the risk that the same species pose when kept as pets under controlled maintenance conditions as significantly lower., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

This study compiled 33 verified spider bites from the state of Oregon (USA). The initial goal was to amass a series of bites by the hobo spider to assess whether it possesses toxic venom, a supposition which is currently in a contested state. None of the 33 bites from several spider species developed significant medical symptoms nor did dermonecrosis occur. The most common biters were the yellow sac spider, Cheiracanthium mildei (N = 10) and orb-weavers of the genus Araneus (N = 6). There were 10 bites from three genera of funnel web spiders of the family Agelenidae including one hobo spider bite and one from the congeneric giant house spider which is readily confused as a hobo spider. The hobo spider bite resulted in pain, redness, twitching in the calf muscle and resolved in 12 h. Also generated from this study were possibly the first records of bites from spiders of the genera Callobius (Amaurobiidae) and Antrodiaetus (Antrodiaetidae), both with minor manifestations., (Published by Elsevier Ltd.)

A significant seasonal correlation was recently shown for brown recluse spider activity. Vetter (2011) observed brown recluse spiders were submitted by the general public predominantly during April-October. For patients with suspected brown recluse spider bites (BRSB), we have observed the same seasonality. Among 45 cases with features consistent of a BRSB, 43 (95.6%) occurred during April-October. Both the Vetter study and our study serve to demonstrate seasonal activity for brown recluse spiders., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The amount of venom injected by the spider Cupiennius salei depended on the efficiency of the mechanical defence of the prey species. Spiders were milked for the first venom (i.e. the first microlitre of venom emitted) versus remaining venom, and for venom regenerated from emptied glands. HPLC gel filtration and IEF electrophoresis showed that the protein content of the first venom was only half as compared to that of the remaining venom, and that this was due to a dilution of all proteins. Venom regeneration came in two speeds. The amount of venom was regenerated more rapidly than the protein concentration. Newly regenerated venom as compared to older venom was characterized by a lower concentration of all proteins and by a higher total concentration of free amino acids, whereas histamine and taurine did not follow this trend. K+ concentration and pH remained similar during venom regeneration. Crickets injected with the venoms showed less acute symptoms when the protein concentration was lower, namely with the first venom and with newly regenerated venom. Consequently, a spider which modulates the quantity of venom injected into a prey also directly changes the venom quality. The ecological consequences of this are discussed. This paper also discusses which region of a gland (ampulla, extracellular and intracellular parts of the glandular sac) is involved in the changes of the venom quality.