Health advisory: Beware the deadly bite of the female red-back spider!

News photo

Keep clear: This poisonous red-back spider was found Monday in Kawasaki. CITY OF KAWASAKI

Red-back spider found in Kawasaki Japan Times Nov. 14, 2012

A poisonous red-back spider was found in the garden of a home in Kawasaki, suggesting the invasive alien arachnid is creeping closer to Tokyo.

The Kawasaki resident found the spider along with an ovisac Monday and used a pesticide on them. The spider was later confirmed to be a red-back, which is listed as an invasive alien species by the government.

The first red-back spider found in Japan turned up in the port of Takaishi, Osaka Prefecture, in 1995, presumably arriving aboard a freighter from Australia.

The National Institute for Environmental Studies has certified that the spider has been located in 18 prefectures since then, but that number is expected to be larger in reality.

“Red-back spiders are pretty harmful,” Masahiro Yoshida, a former Osaka Prefectural Institute of Public Health senior researcher who now heads the Osaka-based Laboratory of Bio Research, told The Japan Times.

He said the spider’s venom can cause a sudden rise in blood pressure and may be lethal to young children or elderly people with heart conditions.

Red-back bites have caused deaths in Australia, Yoshida added, urging municipal authorities, especially in Tokyo, to be on guard.

“Each local government should have an officer in charge of the extermination of poisonous spiders. They should also educate the public on the dangers” of red-backs, he said. Like many other spider species, female red-backs grow much bigger than males and can reach about 1 cm in size.

The spiders, which are black, have a red blotch on their bodies. Only the females are venomous, according to the Environment Ministry. Red-back spiders are usually found in dark, moist and warm places, including inside gutters.

But when an 86-year-old woman suffered a red-back bite in Fukuoka on Sept. 3, the spider was in her shoe. She was taken to a hospital and recovered after taking a shot of serum.

Most municipalities have posted warnings on their websites that red-backs, while not aggressive, will bite if irritated. One should “trample on the spider with their foot or use pesticide for extermination,” warns Joto Ward, Osaka, on its website.


Deadly red-back spider spreads across Japan October 18, 2012, THE ASAHI SHIMBUN

The red-back spider found in Fukuoka city in September (The Asahi Shimbun)

FUKUOKA–A venomous spider endemic to Australia has established colonies across Japan after apparently being brought in on cargo containers.

The red-back spider was first identified in 1995 in Takaishi, Osaka Prefecture, experts say, and by Oct. 1 the spider had reached 22 prefectures, the majority of them in western Japan.

In September, a spider bit a woman in her 80s from the Higashi Ward of Fukuoka city. She suffered breathing difficulties.

While the spiders are not aggressive, the female spider has a virulent poison that can cause spasms and fever. Deaths have been recorded in Australia.

“I have become more aware of whether there are spiders in areas where children play,” said Mikiyasu Koga, 44, who was recently taking his 4-year-old daughter to a park on Higashi Ward’s Island City.

Japan’s Environment Ministry has said the red-back spider is often found near Japanese ports. Officials believe it originally arrived aboard cargo.

The red-back spider was first identified in Fukuoka’s Higashi Ward in 2007 and since then specimens have turned up there every year. But this year saw an increased number of sightings. Last month alone there were 63 recorded sightings, as of Sept. 28.

City officials plan to erect warning signs close to harbor facilities in the neighborhood urging vigilance.

However, city officials say there is no need to panic because the spiders are not aggressive.

“People do not have to become excessively fearful,” said one official.

In June, the red-back was identified for the first time in Shingu, which borders Fukuoka city. In September, one was found near a resident’s front door. That same month, the spiders turned up, too, in Koga, Fukuoka Prefecture, and at the Ground Self-Defense Force Camp Metabaru in Yoshinogari, Saga Prefecture.

Masahiro Yoshida, who heads Osaka-based Ikimono Kenkyusha (“Living Things Research Company”), is a former senior researcher with the Osaka Prefectural Institute of Public Health.

He said red-back spiders prefer temperatures around 25 degrees and often live in ditches or within fence posts. The peak breeding period is summer.

There have been sightings of large numbers at a time. In Amagasaki, Hyogo Prefecture, and Kyoto city more than 100 spiders turned up in city parks in September alone, officials said.

“The spiders’ distribution has spread because of Japan’s warm climate and the relatively few natural predators,” said a Fukuoka city government official.

Many local governments seem unprepared to deal with the problem.

After the woman’s bite in Fukuoka, the city’s stores of antitoxin were all found to have had an expired shelf life.

Under the Invasive Alien Species Law, it is Japan’s central government that should take the lead in extermination efforts.

However, an official with the Environment Ministry’s Office of Alien Species Management said, “Our priority is to exterminate those species that damage biodiversity conservation areas, such as national parks.”

For that reason, extermination of the red-back spiders is being left up to local governments.

“One reason for the spread in the spider’s distribution is the haphazard pattern of extermination efforts so far. The spider’s spread could be stopped through a more carefully planned extermination,” said Osaka’s Yoshida.

(This article was written by Taro Ono and Tomoko Yamashita.)


Advice from the Australian Museum “Redback Spider, Latrodectus hasselti” webpage is as follows:

Danger to humans and first aid

Redback bites occur frequently, particularly over the summer months. More than 250 cases receive antivenom each year, with several milder envenomations probably going unreported. Only the female bite is dangerous. They can cause serious illness and have caused deaths. However, since Redback Spiders rarely leave their webs, humans are not likely to be bitten unless a body part such as a hand is put directly into the web, and because of their small jaws many bites are ineffective. The venom acts directly on the nerves, resulting in release and subsequent depletion of neurotransmitters.

Common early symptoms are pain (which can become severe), sweating (always including local sweating at bite site), muscular weakness, nausea and vomiting. Antivenom is available. No deaths have occurred since its introduction.

Apply an ice pack to the bitten area to relieve pain. Do not apply a pressure bandage (venom movement is slow and pressure worsens pain). Collect the spider for positive identification. Seek medical attention.” — read more about the medical symptoms and treatment at Wikipedia: Redback spider

Advice from WCH Clinical Toxinology Resources:

1. After ensuring the patient and onlookers are no longer at risk of further bites by the spider, the bitten person should be reassured and persuaded to lie down and remain still. Some will be terrified, fearing sudden death and, in this mood, they may behave irrationally or even hysterically. The basis for reassurance is the fact that many bites do not result in envenoming, death is a very rare outcome, and the effectiveness of modern medical treatment.
2. The bite wound should not be tampered with in any way.
3. Some victims find the application of a local cold pack may relieve local pain.
4. Do not apply a local bandage, tourniquet, or cut or suck or incise the wound or apply electric shock. Application of local heat has not proved beneficial.
5. If there is any impairment of vital functions, such as problems with respiration, airway, circulation, heart function, these must be supported as a priority. In particular, both airway and respiration may be impaired, requiring urgent and prolonged treatment, which may include the mouth to mask (mouth to mouth) technique of expired air transfer. Seek urgent medical attention.
6. If the offending spider has been killed or caught it should be brought with the patient for identification.
7. Avoid peroral intake, other than clear fluids, in the first 6 hours, absolutely no alcohol. No sedatives outside hospital. If there will be considerable delay before reaching medical aid, measured in several hours to days, then give clear fluids by mouth to prevent dehydration.
8. Most traditional, and many of the more recently fashionable, first aid measures are useless and potentially dangerous. These include local cauterization, incision, excision, amputation, suction by mouth, vacuum pump or syringe, combined incision and suction (“venom-ex” apparatus), injection or instillation of compounds such as potassium permanganate, phenol (carbolic soap) and trypsin, application of electric shocks or ice (cryotherapy), use of traditional herbal, folk and other remedies including the ingestion of emetic plant products and parts of the snake, multiple incisions, tattooing and so on.

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