Globally, the endemic regions of ciguatera can be superimposed to coral development areas, circumscribed to the intertropical belt, with a predominance for islands /costal territories.
The Caribbean Basin, the Pacific Ocean and the Indian Ocean represent a population of some 400 million people potentially exposed to the ciguatoxic risk.
If ciguatera develops preferentially in lagoons and reef ecosystems, it can however be found in deep coastal waters.
NUMBER OF PEOPLE AFFECTED BY CIGUATERA
The number of annual CP cases worldwide has been estimated at between 50,000 and 200,000, but may represent only 20% of the actual figure.
Indeed, although considered the most widespread non infectious foodborne disease, the data concerning the global population affected suffer from a real lack of completeness, partly due to the lack of information of health care workers and general population, no epidemiological surveillance available and difficulties related to the diagnosis (often incorrect or missing).
In addition, due to the lack of specific and effective treatment, many people prefer to treat themselves without the help of a physician, thus escaping the count since they are not subjected to a declaration.
Few countries have implemented a CP surveillance program or require its systematic report to Health authorities.
This lack of information therefore contributes to the large underestimation of the number of actual CP cases.
IMPORTED CP CASES
The development of tourism, international trade and the attraction for "exotic" products, make marin products consumers from temperate regions new potential victims of ciguatera.
Thus, increasing numbers of so-called "import CP" cases are recorded each year in the United States, Canada, France, Germany, etc. It may be a tourist contaminated during a trip to a CP endemic country, or a poisoning event occurring in a temperate area after the consumption of imported contaminated fish.
Map of imported ciguatera cases
A GLOBAL EXPANSION OF CIGUATERA?
If ciguatera was until recently considered as a problem specific to island and coastal territories of tropical ambiance, we have been witnessing for a few years a gradual expansion of ciguatoxic areas towards more temperate regions, in particular Europe, Korea, southern Australia ...
Thus, indigenous cases of ciguatera (i.e. linked to the consumption of locally caught fish) have been recorded in new regions since the early 2000s, notably in Madeira, the Canary Islands,Vietnam, Indonesia, Malaysia, Macau, Thailand and South Korea.
The emergence of these new “ciguateric risk zones” could find its origin in the effects of climate change by favoring the worldwide proliferation of the toxino-producing microalgae and /or the migration of tropical fish to more temperate regions.