Article 08 April

10 weird travel health mysteries - solved!

From recurring boils to worms that crawl over your eyeballs, the world is full of unusual and downright horrifying ailments. Dr Jane Wilson-Howarth introduces a few…

The unexplained deaths of tourists in Thailand or a new epidemic in China never fail to grab headlines, while hearsay and misinformation can make for macabre medical mysteries. Tales of the weird and wonderful can spook travellers and, perhaps surprisingly, even locals can have serious misconceptions about their neighbourhood creatures. Travel naturally brings with it some health hazards and, if you’re of a nervous disposition, you should look up those you’re most likely to encounter before you go. But here we look at some the world’s rarer and very strangest symptoms.

All in the mind?

One of the oddest medical symptoms is so bizarre that doctors first thought their patients were suffering from hallucinations. Victims reported that when they put their hands into cold water they felt burning hot; if they put their hands into hot water, they felt cold. Eventually this hot-cold reversal was recognised as symptoms of ciguatera poisoning. Ciguatera is caused by consuming fi sh tainted with dinoflagellate toxins. At first it makes the mouth of the eater numb or tingly; 30 minutes to 30 hours later there will be vomiting, cramps and watery diarrhoea that settles in 24-48 hours. The hot-cold reversal sensations come later and take some months to go away. tropical areas and are quite Puerto Rico. People are less likely to experience it if they avoid eating very colourful reef fish and moray eels.

Seeing things

The loa-loa worm of central Africa is transmitted by horse-fly bites, though it produces very different symptoms to the bite itself. Parasitised people experience pricking sensations, itching, aches and pains. Occasionally a worm can be seen journeying across the front of the eyeball.

The vanishing...

A real now-you-see-it-now-you-don’t disease is leishmania, a gift of minuscule biting sandflies. A painless ulcer with a rolled edge develops. It grows for a while, but then appears to heal and disappear. It is then impossible to tell whether the parasite that caused the ulcer is still in the body. In the tropical Americas, around half of people with ulcers due to the leishmania parasite go on to develop internal problems or destruction of the inside of the nose; at this stage the disease is difficult to treat.


Super spitters

Exotic animals can spawn unbelievable travellers’ tales. In South India there is reputedly a creature that lurks under stones that, if disturbed, spits toxin; via the exaggeration of retelling, this creature is alleged to be able to permanently blind people from several metres away. ‘Walkingsticks’ or musk phasmids are one of a range of animals that can squirt irritant substances when threatened. For instance, the Florida ‘stick’ has a range of 40cm; its musk causes pain if inhaled and the eye irritation takes 36 hours to settle. Cicadas and whipscorpions also spray irritants.

Genital intruder

Perhaps the most notorious travel fable concerns a South American fish with a reputation for being able to enter a man’s most delicate appendage; once lodged, it sticks out its spiky fins and the only way to get rid of it is by penile amputation. Although the pencil-lead-thin candiru fish does exist, its favoured habitat is fish gills, not human privates. It is rare for an ordinary traveller to acquire one. Also, genital surgery isn’t necessary – in Amazonian villages where the fish occur, there is usually a local woman who is skilled at winkling them out.

The dancing cure

The name ‘tarantula’ is given to the most dangerous Italian spiders (including black widows). If bitten by one, the victim succumbs to ‘tarantism’, a hysterical condition that causes them to become feverishly hyperactive and jittery. The remedy is the fast-tempo tarantella dance – considered a medical exorcism, it supposedly cures the convulsions and other dangerous effects of the toxins; the more noise made by the victim’s friends, the more likely is it that the victim will survive.

Stinging sea

Swimming among slicks of floating seaweed after stormy weather in the tropics can be spooky. It is easy to imagine the things that could bite or sting you. Then things DO start to sting. You are not imagining it – pieces of jellyfish break off in storms, leading to the sensation that the sea itself is stinging you.


Also known as sleeping sickness, African trypanosomiasis follows a tsetse fly bite. Victims become increasingly apathetic, confused and stumble about. They keep falling asleep, even while standing. As the disease progresses, sleep episodes become longer until coma, then death ensues.

Allergy to the ocean

A few hours after bathing in tropical seas, some swimmers notice raised red wheals lasting several days. The rash is worst under bathing suits or places where the skin gets rubbed. It is a reaction to the larvae of minuscule thimble jellyfish (which can spring up sporadically, when jellies are washed inshore) but affects some worse than others. The rash will recur when the same swimsuit is put on, though washing the cozzie will solve the problem.

Persistent pustules

Recurrent boils in returning travellers can look like the unpleasant but not uncommon skin problem that many of us suffer on occasion. But sometimes they just keep coming back, despite courses of ‘normal’ antibiotics. It may turn out to be an MRSA: while most people think of it being specifically a hospital infection, MRSA can be acquired through close contact or in less-than hygienic environments.

Winding worms

If you accidentally swallow tiny (1-2mm long) water fleas when you drink from an open-water source in Africa, you may inadvertently ingest guinea worm larvae. One year later, painful blisters form on arms or legs. These burst and expose the tail of a long (100cm), thin (1-2mm diameter) worm, which can survive under the skin for years. The traditional method of removal is to wind it laboriously around a stick, withdrawing it gradually each day. Some say that the medical symbol of a serpent wound around a staff originates with this treatment. Infestation is most likely in Sudan but even there it is vanishingly rare.

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