The Herpetological Society of Ireland

 

A story was published in The Sun newspaper today, suggesting that the death of a man in Cork may be the result of a spider bite that occurred the previous year. The piece gained traction and has since been published and shared via several news and social media outlets. Everyone here at the Herpetological Society of Ireland would like to begin by extending our sympathy to the family and friends of the deceased. However, we have several concerns surrounding the story and we feel it is imperative that these issues be addressed for the sake of balance and to allay any concerns this piece may have triggered. We asked Dr. Michel Dugon, an expert on the evolution of venom systems at NUIG,  to address these concerns…

 

Did a black widow spider really kill Cork man John Kennedy?

“The death of John Kennedy is a tragedy, and it is only normal for his loved ones to wonder why and how the father of five died so unexpectedly. However and contrary to what has been suggested in many news reports, it is highly unlikely that an Australian black widow spider –or red back- is the cause of his death. Here is why.

Virtually all spiders in the world produce a toxic blend of chemicals called venom in order to eat their prey and defend themselves. Venoms are complex blend of toxins specific to each species of spiders. In human beings, the venom of the red back produces an array of symptoms known by the medical community as latrodectism.

Latrodectism is characterised by muscle pain, spasm, hypertension, fever, headache, anxiety, nausea and vomiting. Despite popular belief, the symptoms are not life threatening in 95% of cases. In less than 5% of cases, the victim might die of cardiovascular collapse if no medical care is given. In fact, nobody has died from a black widow bite in Australia since the introduction of an anti-venom in the early 1950’s. The symptoms of latrodectism start 30 minutes to 6 hours after the bite and last generally 18 to 48 hours.

Because venoms are chemically so complex, they are also highly unstable. Toxins start breaking down into less potent compounds just minutes after being injected. While the symptoms of an envenomation may last for years, there are no report of venom remaining dormant for months before “waking up” and causing general organ failures as suggested in the case of Mr Kennedy.

The actual mechanical bite of a red back is neither painful, nor does it bleed profusely. Black widows are small spiders measuring barely an inch long as adult. Their fangs, which they use to bite, are only a couple of millimetres long and half a millimetre thick.

While spiders have been known to be imported via international shipments, accidents involving exotic spiders are extremely rare anywhere in Europe. Because of its ecology and physiological requirements, it is virtually impossible for a population of red back to settle and breed in Ireland.

Of the 44,000 species of spiders worldwide, only a handful has the potential to give a life threatening bite. In Ireland, none of the 400 species of spiders are known to deliver medically significant bites, and only 10 species are capable of breaking the human skin with their fangs.

There is no reason to doubt that Mr Kennedy has been bitten by a spider last year. However, considering the elements reported in the news it is virtually impossible that the spider -whether it was a red back or not- had anything to do with Mr Kennedy’s tragic end.”

Dr Michel Dugon

Adjunct lecturer in Zoology at NUI Galway

Specialist of the evolution of venom systems.

 

The response to this story on social media has largely been one of fear and panic. Many people have suggested that they will kill any spider or bug they encounter “just to be safe”. This is entirely unnecessary. Spiders are an important part of Ireland’s natural heritage and they are an integral part of our ecosystems. The odds of encountering a dangerous, exotic species are staggeringly low. If you are curious about a particular species, feel free to take a photo of it and contact us for identification. As ever, the best tool you can employ when confronted with fear is education. If you wish to learn more about these fascinating, but unfortunately misunderstood creatures, please feel free to contact us.

 

Many thanks to Dr. Michel Duggon for his assistance and to Fionnan Burke for conducting the interview.

 

Photo credit:  Toby Hudson