Ciguaterror!

9 Jan
Looks delicious, right?

Well my Bahamas ‘vacation’ was wonderful- chaotic but oh-so-much fun and quite the learning experience. I feel maybe twice the sailor I was when starting the trip, which is a nicer way of saying I have no idea what I’m doing out on the water. An unsurprising corollary to the fact that most of my sailing lessons have been learned the hard way, including most of the ones on this trip. Still, as long as there’s not too much blood involved most of the time I’m just happy to have learned something and there are only a couple lessons I would be glad to trade in for blissful ignorance. This latest one about Ciguatera poisoning? Well, it could have been a lot worse, but it does make the list…
If you’ve spent any time in tropical waters and you eat fish you’ve most likely heard of Ciguatera poisoning, probably something terrifying about a potent neurotoxin which is undetectable, undamaged by cooking, and seems to be found in only the most delicious fish species. Unfortunately, that’s all more or less true. Ciguatera sickness is caused by toxins present in various plankton that live on and near reefs between latitudes 35 degrees North and 35 degrees South. It is a bioaccumulator, meaning that as the plankton which produce it are eaten by herbivorous fish and these fish are eaten by other, larger fish it moves up the food chain. For this reason it is most often present in top-predator reef fish- barracuda, amberjack and grouper are some of the most common carriers, and larger fish are more likely to be toxic than smaller, younger fish (Our fish was not particularly large but at maybe 12lbs it was a bit heavier than the 10lb limit recommended by some).

Gambierdiscus toxicus a ciguatoxin-producing plankton. Photo Credit:  David Patterson and Bob Andersen

As a sailor it is a rather disturbing thing to know that many of the fish which we so enjoy catching and eating could be the source of a potentially very nasty illness. So what do we do? Well, all sorts of things. Some people swear off reef fish, or reef fish of a certain length. Others look to more esoteric detection methods, watching if flies land on the fish, or whether ants will crawl on it, or they cook fish only in pans made of 19th century Chicago pig iron and with the inclusion of an Indian head penny… Ok, I made the last one up but ways to ‘detect’ Ciguatera can get pretty far out there and like most medicine that relies on some sort of talisman much of this seems dubious to me. The alterative taken by many, myself included, is to avoid one or two types of fish (Barracuda are supposed to be particularly suspect) and then just take our chances. Mostly we try not to think about it, especially right after a delicious meal.

For my shipmates and I this was a no-brainer, we were firmly in the eat-it-and-don’t-think-about-it camp and we ate fish, lots of any fish we could catch. At least two of us did, the other half of the crew being conveniently uninterested in the not-so-large fish we were catching. While eating all this fish we were doing such a great job of not thinking about Ciguatera that it didn’t even come up in conversation until the morning Emory and I woke up with the same weird symptoms of general malaise and an ache in our joints and muscles. At the time this seemed only a little odd, neither of us had slept well in days and there had been plenty of rowing the day before so a few aches and pains seemed in the cards. The fish we had eaten the previous night, a jack of some sort (Jack Crevalle?) was brought into question. Somehow we decided that there were so many possible explanations that we may as well stop worrying about it and have a nice fish breakfast which in retrospect may not have been the best idea.
What came next slowly convinced us that Ciguatera was the only reasonable explanation. Our initial symptoms were somewhat atypical of the illness: joint pain, malaise, and headaches (which Emory had, but not I) are all standard fare but typically Ciguatera sickness begins with a period of vomiting and fevers. Without these we were reluctant to go around claiming some exotic illness when we were maybe just fatigued. Still when we were both feeling quite awful well into the afternoon we did (with difficulty) decide to throw the rest of the fish out. For a couple days we ignored the joint and muscle pain as well as we could, even spending Boxing Day dancing all night at a Junkanoo parade. Again, with lack of sleep and plenty of physical exertion our sore muscles weren’t so hard to explain away. It wasn’t until four or five days later when the truly weird symptoms kicked in that we realized it had to be due to the fish.

Chemical structure of a Ciguatoxin

Ciguatera, it turns out, is actually a neurotoxin and along with aches, pains, and gastrointestinal issues it can bring on very odd neurological symptoms. The classic two, which both Emory and I experienced a few days after eating this fish, are paresthesias and cold allodynia. The first, parethesias, is a tingly feeling similar to that of a limb that has ‘fallen asleep’ and is regaining blood circulation. Both Emory and I felt this in our hands and feet, especially in our digits. Oddly enough, we also seem to have this in our tongues which are tingly and sensitive to cold. To me it feels as if I had lightly burned my tongue on a hot drink, but the feeling does not go away! The second hallmark symptom, cold allodynia, is a feeling of a sort of burning pain when touching something cold, like a cold/hot reversal. This is also in our hands and feet, primarily in our digits, and is quite uncomfortable at times, particularly when washing hands with cold water. 
We were lucky though in that we seem to have had a relatively small dose of toxins, although Emory got it a bit worse than I did. For me this stuff is a little annoying but mainly it is just weird, especially the feeling of numbness in my tongue and the cold/hot reversal. These have persisted, more or less all the time, for the past two and a half weeks. I have also been feeling fairly under the weather during this time and am sick at the moment with what feels like a flu. I suspect that the ciguatera is still having some general effect on my immune system but again it is hard to tell as the past couple weeks have been hectic enough that getting sick is no surprise

I don’t expect the flu will last long, but as for the ciguatera symptoms I’ve no way to know. There is surprisingly little information on the internet about the illness and like most internet health stuff it is full of ambiguities. The symptoms apparently can last from days to years and may or may not flare up at a later date but I’ve read nothing that speaks with any confidence about the relative likelihood of a long vs. short illness, nor any hard numbers about the amount of toxin needed to produce illness, or the rate at which it is dispelled from the body. For that matter, I’m not even sure if it will eventually leave my system or if I simply adapt to it. Most sources agree that over time the symptoms go away but I read conflicting things about whether the toxins actually leave the body or not. In the meantime, I’ll let you know how it goes! Like I said, this small dose is not much more than an inconvenience and at least it’s intriguing, much more so than this damned flu I’m battling. 

If you have more information about Ciguatera, especially if you know any medical professionals who specialize in this stuff and wouldn’t mind answering a few questions I would love to hear from you. I’m also very curious to hear from anyone who has had the illness. It seems to be quite a bit more common than I had thought. 

This article was syndicated from Safe At Harbour But Meant For The Sea: DIY Sailing with Paul Calder

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