Bite envenomation by Latrodectus geometricus (Araneae: Theridiidae) spiders in Malaysia

Abstract

We report two confirmed human bite cases by Lactrodectus geometricus, also known as the brown widow spider. These are the first reported bite envenomation incidents by L. geometricus in Malaysia. The incidents occurred in Tawau, Sabah and Paka, Terengganu. Both men were bitten on their ear while putting on motorcycle helmets. The spiders appeared to have nested in the helmets. The dead specimens were collected and sent to the

Challenges in the diagnosis and management of brown widow spider (Latrodectus geometricus) envenomation in dogs

“…A distinctive feature is the presence of a distinctive hourglass or diamond-shaped pattern on the underside of the abdomen, which is a clear indicator of the species. The females, which are typically larger than the males, can vary in length from 6 to 20 mm (Earwood, Ladde, Giordano, 2020;Khamtorn et al, 2020;Khamtorn et al, 2021;Mokhtar et al, 2021). These morphological and coloration characteristics are consistent with the descriptions of Latrodectus geometricus in the scientific literature.…”

“…Local signs, such as edema, erythema, and pain, observed in both canine patients of this report, are commonly reported in cases of araneism by brown widow in humans (Goddard et al, 2008;Almeida et al, 2009;Monte, Bucher-Bartelson, Heard, 2011;Earwood, Ladde, Giordano, 2020;Mokhtar et al, 2021). Although the neurotoxic fraction of the brown widow venom is more studied, it is known that the metalloproteinases present in the spider's venom are also important and contribute to dermonecrosis, as observed in the first case described in this study (Kira).…”

“…The systemic symptoms observed in the patient Troya, such as vomiting, ambulatory tetraparesis, and ataxia, have already been documented in reports of accidental envenomation by brown widow spiders in humans (Goddard et al, 2008;Kiriakos et al, 2008;Almeida et al, 2009;Monte, Bucher-Bartelson, Heard, 2011;Earwood, Ladde, Giordano, 2020;Mokhtar et al, 2021) and in experimental studies with mice (Reyes-Lugo et al, 2009). However, the occurrence of epileptic seizures and renal and hepatic failure, followed by circulatory collapse, represents more severe manifestations that had not yet been described in works related to human envenomation.…”

“…The importance of studying araneism caused by the brown widow spider (Latrodectus geometricus) is evidenced by its global distribution (Brown, Necaise, Goddard, 2008;Vetter et al, 2012;Muslimin et al, 2015;Keyler et al, 2020;Khamtorn et al, 2020;Caruso et al, 2021) and reports of human envenomation (Goddard et al, 2008;Kiriakos et al, 2008;Almeida et al, 2009;Monte, Bucher-Bartelson, Heard, 2011;Earwood, Ladde, Giordano, 2020;Mokhtar et al, 2021). The presence of the brown widow has been confirmed in almost all countries of the Americas, including Brazil, indicating its wide distribution and potential to cause accidents in various regions.…”

“…The brown widow spider (Latrodectus geometricus) is one of the thirty-one species of the genus Latrodectus and has gained notoriety due to its potential for envenomation in both humans and animals (Kiriakos et al, 2008;Mokhtar et al, 2021).…”