On a tropical island vacation, one of the last things you want to worry about is food poisoning. Yet for many, a trip to the tropics includes a painful education in a mysterious food-borne illness called Ciguatera Fish Poisoning, or CFP.
Every year, thousands of people suffer from CFP, a poisoning syndrome caused by eating toxic reef fish. CFP symptoms are both gastrointestinal and neurological, bringing on bouts of nausea, vomiting, diarrhea, headaches, muscle aches, and in some cases, the reversal of hot and cold sensations. Some neurological symptoms can persist for days to months to years after exposure. There is no quick way to test for the toxins, and unless action is taken within hours of the poisoning, no cure once you’re sick.
On some small islands in the Caribbean and South Pacific, it’s estimated that CFP can affect more than 50 percent of the population. Ciguatera runs like an undercurrent through these communities, not always visible at the surface but having vast economic and public health impacts. CFP is consistently underreported because of both misdiagnosis and a reluctance of local people to go to the hospital or local clinic when sick.
That’s why I’m here in St. Thomas, diving in water the color of an unclouded sky for a near-invisible quarry. Amidst the coral and seaweeds, fish appear like bright flashes in the shadows and light. They tear and scrape food from the algae and dead corals. I reach down and enclose some seaweed in a plastic bag, collecting not only the seaweed, but also thousands of tiny hitchhikers. I’m hoping to find elusive cells sticking to that seaweed.
These microscopic cells, called Gambierdiscus, produce the toxins that cause CFP. By learning more about their genetics, I hope to find out how they grow in different environments and how that affects the risk of CFP around the globe.
Tropical reef fish image via Shutterstock.
Read more at Woods Hole Oceanographic Institution.