Medical risks and prevention
I - Tropical diseases
Compared to other tropical zones the risks of serious illnesses in the Lesser Antilles are extremely low if one takes basic precautions.
No known risk in this zone.
No official cases in the Lesser Antilles although they are close to countries at risk.
Quite common in the Lesser Antilles. Dengue fever is spread by the same mosquito that spreads yellow fever.
Symptoms Generally like a bad case of influenza: aching joints, fever. The rare, haemorrhagic dengue fever is serious.
(intestinal variety – schistostomiasis (S. mansoni)
An illness caused by a parasite penetrating the skin. The parasite lives in freshwater rivers and brackish ponds etc, polluted as a result of nearby housing (quite common in the poorer islands with ill-maintained, inadequate or non-existent drainage and sewerage).
Symptoms Marked lassitude and stomach pains.
Treatment After relevant tests, treatments by oral medicines are now extremely successful.
Prevention Don’t wash or swim (even feet only) in fresh water, which might be polluted.
This is essentially a parasite which is a problem for dogs. As far as the effects on humans go, the parasite in its pre-adult stage moves around under the skin causing major itching.
Treatment Insecticide ointment or, in a hospital, treatment by topical chilling.
Prevention Don’t walk around in bare feet or lie around on beaches contaminated or soiled by animals. Note beware of other intestinal parasites that can infect you. This happens, as with bilharzia, in a wet environment, but also by eating contaminated fruits and vegetables. The phenomenon is often known as ‘la tourista’ or Pharaoh’s Revenge.
Vaccinations No vaccinations are obligatory for travel to the Lesser Antilles. However, as a precaution you can get vaccinated against: tetanus, smallpox, polio, hepatitis A.
II - Attacks and poisoning
There are no land animals dangerous to humans in the Lesser Antilles except in Martinique, where the bite of the viper fer-de-lance can be dangerous and even fatal.
Dangerous marine animals
Sharks Species found in coastal waters are generally harmless, in particular the sand shark, nicknamed ‘the sleeper’, which is the most common.
Accidents are the exception. Two have been recorded in the Virgin Is. When spear fishing, avoid attaching the fish you’ve caught to your belt.
Barracudas Contrary to their reputation and their aggressive demeanour, barracuda don’t normally attack divers. On the other hand, if they’re wounded, they can bite the underwater hunter who takes them.
In the marine environment there are other more common but less dangerous attacks:
•jellyfish tentacles can cause nasty stings
•wounds from the spines of sea urchins
•burning or stinging corals or ‘fire corals’
•recently, a new species within the scopaenidae family, introduced to the area by man, has presented an added danger to divers. Although its flesh is edible, the Red Lionfish is covered in venomous spines.
One quickly learns to recognize these ‘dangers’ by experience. They’re no danger to life and limb but are always thoroughly unpleasant!
These are rare, with the exception of the Manchineel tree. This is a very common coastal tree in the Antilles with fruit ranging from green to red looking like small apples (manchineel fruit). They also smell. Eating these fruits causes dangerous internal burns that can be fatal. The sap of the manchineel can also burn the skin.
Although less widespread than in the Pacific Is, in some of the Lesser Antilles there is a genuine risk of significant fish poisoning from ciguatera. There are few informative sources for the tourist or cruising sailor to consult about the dangers of eating poisonous fish.
Definition Ciguatera is a food toxin ingested through eating the infected flesh of certain fish. The toxin is always found in some species of fish but only occasionally in others. This depends on the size of the fish, its habitat and the season when the fish was caught. The fish eats the toxin that in turn contaminates its flesh. The toxin isn’t found in only one variant, at least six have been identified, but all fall under the generic label of ciguatera.
IMPORTANT: the toxin is thermostable, which means that cooking does not eliminate it.
The toxins come from the marine microorganism, gambierdicsus toxicus, a microscopic algae. The most usual areas of ciguatera contamination are broken or damaged reefs. Fish that eat the algae store the toxin, which then builds in quantity as it proceeds up the food chain. This explains the greater toxicity of the major predators at the top of the food chain.
Symptoms The incubation period can vary from a few minutes to several hours, but is usually fairly swift. The first symptoms are in general simultaneously neurological and intestinal:
• intestinal: nausea and vomiting
•neurological: feeling queasy, tingling feeling (pins and needles)
Before long these symptoms enter a second, more serious phase:
• intestinal: diarrhoea and powerful abdominal cramps
• neurological: burning sensation or a feeling of electric shock if one touches something cold or water, strong itching sensation (called ‘la gratte’ or ‘the itch’), loss of muscular control and balance
• cardio-vascular: irregularities in heartbeat
• more general symptoms: muscle and joint pains, disorientation, reduced quantity of urine and extreme general lassitude
These symptoms can get worse and one can also see cutaneous symptoms, pruritus, loss of hair and teeth, respiratory paralysis and cardiac arrest leading, if rarely, to death.
• corticosteroids (with anti-shock properties) by intra-muscular injection (avoid abuse)
• heart stimulant
• vitamin B
• gastric lavage
Hospital du Lamentin, Martinique, is a specialist centre for the treatment of ciguatera.
In mild cases of ciguatera, the above treatments may be enough to avoid the necessity for hospitalisation. If hospitalisation is required, the French or American Antilles have more elaborate facilities for treatment although none are absolutely effective in all cases.
Prevention of ciguatera The only guaranteed prevention is not to eat potentially contaminated fish. Unfortunately there is no way as yet to detect such fish beforehand. Some believe in tests that seem a bit like sorcery and certainly offer no guarantees.
• offer a bit of the flesh to ants which will avoid it if it’s poisonous
• a piece of pure silver is said to turn black if the fish meat is poisonous
• give a cat some of the suspect flesh (up to 1/10th of the cat’s bodyweight). If 24 hrs later the cat isn’t ill, the fish is supposedly OK and edible. This procedure, even more dubious than the others, requires one to have several small cats around to spare
Even if it’s no absolute safeguard, the best prevention always lies in choosing the right sort of fish.
Note In some islands (Guadeloupe), local legislation defines succinctly which fish are poisonous and not to be eaten. Even in a single species toxicity can vary from island to island. Only fishermen have a good idea of how to make a choice. Though even they may make the occasional mistake. The following selective information is the result of research amongst fishermen and other local people, consultation of hard-tocome- by books and personal experience. The advice appears here with all the usual cautions about following it.
Fishing zones Some people say the Antilles can be divided into two parts:
• from Dominica to the Virgin Is fish are considered dangerously toxic
• S of Dominica all fish are considered edible.
The reality is less black and white:
• It is known that ciguatera is possible S of Dominica and even, for some very hazardous species, as far S as Martinique (barracuda, jacks and pompanos, etc).
•By contrast, further S ciguatera poisoning does seem much rarer at least as far as Grenada, but in the islands near Venezuela ciguatera reappears. The most dangerous area is N of Guadeloupe.
Fishing season There doesn’t seem to be a correlation between season and degree of toxicity. However, some think that risks are greater in the summer.
Fish size Toxicity is proportional to the weight of the fish. For a given species a larger fish is more likely to be poisonous than a smaller one. In some occasionally poisonous species one additional safeguard is not to eat any specimen weighing over 1kg.
Note In order to better recognize the different fish species, it is recommended you get hold of a specialised illustrated guide to fish species such as Guide to Corals and Fishes by I & J Greenberg (Seahawk Press).
In the relevant zones one must be aware that there are several levels of risk depending on species. Some are thought dangerous or very dangerous, others of lesser or doubtful risk. Toxicity can also be a function of the zone where the fish are found. The following selection is only based on experience and you are advised, if you have the smallest doubt, not to eat any specimen.