Saturday, December 03, 2011

Killer bananas

It’s a fantastic plot for a science fiction, don’t you think? “Revenge of the killer bananas!” However if you believe some people the risk is real.

Like many others I received an email a few days ago that began:

“Do not eat bananas until further notice. PNP will investigate if there is any truth in this, but rather be safe.”

The email then explained the danger posed by these homicidal fruit.
“Please don't eat bananas for the next 3 weeks. Several deliveries of bananas from Uvongo Kwa-Zulu Natal South Africa have been infected with necrotizing fasciitis, otherwise known as flesh eating bacteria. Recently this disease has decimated the monkey population in the south coast. We are now just learning that the disease has been able to graft itself to the skin of fruits in the region, most notably the banana which is one of South Africa’s largest exports. Until this finding scientists were not sure how the infection was being transmitted. It is advised not to purchase bananas for the next three weeks!!!”
The email continued to explain how the FDA hasn’t issued a warning because it fears “a nationwide panic”. It also said that if you have an infected wound and are far from medical attention “burning the flesh ahead of the infected area is advised to help slow the spread of the infection.”

Are you feeling scared yet? Or just skeptical?

To begin with there’s a minor technicality. The FDA is a US body, not South African. Then there’s the “science” part of it. Let’s be honest about one thing. You do NOT want to develop necrotizing fasciitis. It’s a horrible bacterial infection that causes massive irreversible tissue damage and often results in either amputation of the infected body part or death. If you want to see some scary pictures do a web search but don’t do this while eating. However, can you actually catch necrotizing fasciitis from the skin of a banana?

No. The Centre for Disease Control in the USA says that there “is no evidence that necrotizing fasciitis is transmitted by food. The bacteria which most commonly cause necrotizing fasciitis live in the human body. The usual route of transmission for these bacteria is from person to person.” There is also little sense in the statement about the “disease has been able to graft itself to the skin of fruits”.

This story is a hoax. In fact it’s a very old hoax. This has been circulating around the internet for at least 12 years. It was first seen in 1999 but with a slight difference. That time it mentioned Costa Rica, not South Africa but the words in the email were otherwise exactly the same.

You can rest assured that eating bananas is still safe and they’re still good for you. You’re not going to be turned into a zombie by eating them.

However, what I find just as interesting is why people continue to send these emails. I know of several people who’ve received it and a couple who forwarded it to others. I know of one person who even posted it on Facebook. I’m sure all of these people were perfectly well-meaning and genuinely felt it was important to warn their friends about a possible risk but did they really believe the story or were they so shocked and horrified that they felt it was an emergency?

Or are they perhaps just a bit more suggestible than others? A bit less naturally skeptical? Psychologists have certainly identified that there is a scale of suggestibility with some people being more prone than others to believe what they see and hear. They are much more susceptible to suggestion, particularly with things like hypnosis but I suspect they’re just as susceptible with anything new, like emails about bananas.

I sometimes think that I’ve become overly skeptical at times, automatically assuming that something is not true until it’s proven to be so, But then I remind myself that I think this is by far the safest approach to take to life. Isn’t it better to assume what scientists call the “null hypothesis”, that something is NOT true until there’s a good reason to change your mind? That certainly goes for anything you receive in your email inbox and anything that makes remarkable claims. Sa Carl Sagan said, “remarkable claims require remarkable evidence”. There’s nothing remarkable about the killer bananas story other than the fact that people believe it.

Sources

Snopes has a report of the original hoax email that referred to Costa Rica here. There are several useful links at the end of the article. The Skeptic Detective has a comprehensive piece on the hoax here.

The official Centre for Disease Control statement can be seen here and there's a very assertive statement from the Kwa-Zulu Natal Banana Association (I SO want to join!) here.

If you're feeling brave and want to learn more about necrotizing fasciltis you can see the Wikipedia page here which includes a fascinating but ghastly fact about the death of King Herod.

The full text of the email I received is as follows:
"Please don't eat bananas for the next 3 weeks

Several deliveries of bananas from Uvongo Kwa-Zulu Natal South Africa have been infected with necrotizing fasciitis, otherwise known as flesh eating bacteria. Recently this disease has decimated the monkey population in the south coast. We are now just learning that the disease has been able to graft itself to the skin of fruits in the region, most notably the banana which is one of south africa ’s largest exports. Until this finding scientists were not sure how the infection was being transmitted. It is advised not to purchase bananas for the next three weeks!!! If you have eaten a banana in the last 2-3 days and come down with a fever followed by a skin infection seek MEDICAL ATTENTION!!!The skin infection from necrotizing fasciitis is very painful and eats two to three centimeters of flesh per hour. Amputation is likely, death is possible.. If you are more than an hour from a medical center burning the flesh ahead of the infected area is advised to help slow the spread of the infection. The FDA has been reluctant to issue a country wide warning because of fear of a nationwide panic. They have secretly admitted that they feel upwards of 15,000 South Africans will be affected by this but that these are" Acceptable numbers". Please forward this to as many of people you care about as possible as we do not feel 15,000 people is an acceptable number."

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