Dangerous Animals in Mauritius

In general, Mauritius is a very safe country. However, there are some health hazards that exist, caused by a number of living creatures. The main threats are summarised below, but this should not be considered as comprehensive and does not constitute medical advice. If in doubt, consult a health professional.

There is no need for paranoia once you have read this! You can still go out and about and enjoy yourself, just use a reasonable amount of caution in certain situations. Many of these health hazards are found in a large number of other countries, possibly the country from which you relocated, and are not life-threatening. It is always better to be well-informed, just in case the unlikely happens.

Although mosquitoes are plentiful in Mauritius, diseases spread by them are not widespread, although they do exist. There are occasional cases of malaria but certainly not enough to warrant taking anti-malarial medication. In the last five years there have also been outbreaks of chikunguna (flu-like symptoms with muscle and joint pain) and dengue fever (flu-like symptoms), although both are not widespread by any means. These diseases are spread by different species of mosquito, that bite in the day (chikungunya and dengue) and at night (malaria) so ideally you should always wear insect repellent and take other precautions such as wearing long sleeves and trousers, burning coils, etc.

The yellow wasp/mouche jaune can give a painful sting and is capable of giving multiple stings in one go. Various treatments suggested locally include slicing an onion in half and applying the cut side to the skin, vinegar or human urine! Stings can swell and be very painful but will fade in a few hours up to a few days, depending on their severity and your body's reaction. If you are allergic to wasp stings seek medical assistance immediately.

Sea urchins abound in the waters around Mauritius and vary from being just annoying to potentially fatal. They are seen in shallow and deeper water. Protective footwear should be worn in the sea at all times; cheap plastic swimming shoes can be bought at larger supermarkets or in tourist shops. Urchins are generally found on or around rocks but some species rest on the sea bed and can easily be accidentally trodden on.

If you get spines in your skin from urchins such as the math urchin then you are advised to immerse the skin in very hot water (without scalding) and try carefully to remove the spines. If some break off or are embedded then seek medical advice. The area will be sore but the urchin is not toxic.

Far more serious is the flower urchin, which is very toxic despite its pretty pink and white colour. It does not have long spines like the other urchins but is covered in what look like tiny pretty flowers, which hide the small spines underneath.The toxin is passed through the 'flowers' and because they are so small they can only sting people in the skin between their fingers. The pain is immediate and can be intensely painful, sometimes resulting in collapse and death in severe cases. If stung, remove the spines and immerse the skin in very hot water, apply antiseptic and seek medical advice immediately. These are commonly seen in lagoons on the sea floor, and just look like a piece of coral or rock, so always wear something on your feet while swimming.

There are several species of starfish found in Mauritius but one in particular is a great nuisance. The crown-of-thorns starfish actually feeds on coral and can destroy huge areas of our coral reef. In addition it releases toxins into the body, if touched, and will cause pain as well as headaches and sickness. The affected part should be immersed in very hot water and kept still until medical advice is sought.

Marine molluscs or sea snails present a minor hazard, mostly in the form of cone shells. There are several species of cone shell that are poisonous. They are found buried in the sand and have a poisonous dart that they shoot into their prey from the narrow end of the shell. They only present a danger to humans if you try to pick them up. The sting will be painful and if there were multiple stings from a larger animal then it could result in neurological damage and/or death. The best prevention is to avoid picking shells up or digging with your hands for live shells in the sea or on the shore. Antidotes are not available, so if you are stung you must immerse the affected area in very hot water and seek medical advice immediately, taking the shell (carefully!) with you for identification, so that your symptoms can be alleviated.

Fish can present a variety of hazards to humans. Firstly, there are some fish that are poisonous when eaten, even when cooked, this is known as ciguatera poisoning. Reef fish such as grouper, snapper, sea bass and barracuda can be affected after eating infected smaller fish, coral or seaweed. Local fishermen will know which species of fish tend to be affected and there is little risk unless you catch and eat your own fish! There are also fish such as the stone fish (laffe laboue) and scorpion or lion fish (laffe corail/laffe volant), which can inject unwary swimmers or paddlers with poison if touched or trodden on. Again, wearing plastic shoes should reduce the risk, particularly from stone fish. These are very well camouflaged and really do look just like large stones on the sea floor, but have 13 spines down their back that inject a toxin. The result is severe pain, paralysis and possible death. Rinse the area and immerse the wound in very hot water, then seek medical attention to obtain the anti-venom (supposedly some hotels have anti-venom). Lion fish are coloured bright red and white, so are much more easily seen and avoided. They are often encountered by divers, floating around wrecks. Their long poisonous spines are obvious and will be used as a weapon if provoked. The sting is extremely painful and the affected area should be rinsed and then put in very hot water and medical advice sought.

There are other species of fish that present threats to unwary swimmers such as leaf fish (poisson feuille), and the same general rules apply if you are stung - rinse the area, immerse in very hot water and seek medical assistance. You can see what these fish look like in any of the Mauritian/Indian Ocean fish identification books that are available locally.

In brief:
Corals should not be touched, trodden on, or interfered with in any way, but swimmers should particularly stay away from fire coral (corail de feu) which will give you a nasty stinging sensation. The coral is yellowy cream with white tips and can be found in shallow water up to 20 m deep. If the coral breaks the skin you should keep an eye on the wound, which may well become infected. If you do come into contact with this coral wash the area and, above all, do not rub it. You can apply vinegar or cortisone cream to relieve the pain and itching. Get medical advice if the wound continues to give problems or does not heal.

Various species of jellyfish occur in the waters around Mauritius but most are harmless although may give a gentle sting if touched. Avoid larger species of jellyfish such as the Portuguese Man-of-War, which can administer painful stings that can be fatal.

After all those hazards in the sea you might think it was safer to swim in freshwater lakes or rivers, but this can sometimes be a health hazard as there are parasites, sometimes hosted by freshwater snails, that infect the water and can cause parasitic infections such bilharzia (schistosomiasis). The parasite enters through your skin or if you swallow water and will complete its lifecycle within your body, potentially causing organ damage and long-term problems. Treatment is in the form of tablets.

Finally, it is worth mentioning here that, as with most other countries, there are a number of toxic plants, many of which are found in our own gardens. For example, yellow bells is reputed to have poisonous sap. See the book Natural Toxins and Poisonous Plants of Mauritius by A. Gurib-Fakim and J. Gueho to find out more.

References