Clinical signs

Ciguatera poisoning is characterized by the wide diversity of its symptoms, which are generally grouped into 5 main categories: gastrointestinal, neurological, cardiovascular, rheumatological and general symptoms. More than 175 different symptoms have been reported in the  literature.





Organs and systems affected by ciguatoxins




Symptoms potentially observed in ciguatera cases





To date, there is NO BIOLOGICAL TEST to confirm the diagnosis of ciguatera.

Currently, the diagnosis of CP is based solely on the history of food poisoning; the species consumed and the nature and evolution of the symtpoms. Only the research for CTXs in leftover meals can confirm the exposure to CTXs. Certain symptoms such as paraesthesia (itching, burning, numbness) of the extremities, face, mouth and pain on contact with cold objects or liquids, as well as the  worsening of symptoms after the consumption of certain foods, can be considered characteristic of ciguatera.



Ciguatera diagnosis tools




Usually, ciguatera has a low mortality rate (<0.1%) and so far has not been associated with the onset of critical illness (cancer, neurodegenerative pathologies,…). Rare fatal cases occur within the firts 48h after the poisoning and are usually due to  cardiovascular and central nervous failures, worsened by severe dehydration caused by intense diarrhea and vomiting.

No fatalities directy related to CP were observed during the chronic phase.

Despite that this illness may prove to be particularly debilitating for a long period, up to a decade in rare cases, the symptoms subside spontaneously.

In addition, if ciguatera is not “contagious”, it has, by some aspects, a “communicable” nature either by sexual contact (which could explain the occurence of vulvar pruritus in women during intercourse with a partner suffering from ciguatera, or pelvic pains in men during ejaculation); or by mother to child transplacental or breast milk transmission. In the latter case, it is strongly advised that mothers stop breastfeeding their child for at least 1 month.

Finally, in rare cases, ciguatera may cause premature births and miscarriages in case of poisoning during pregnancy. 



Symptoms evolution


Usually, the CP ”INCUBATION PERIOD”, i.e. the period between the consumption of toxic meal and the onset of symptoms, ranges from 6h to 12h, in most cases.



The FIRST SIGNS of the poisoning are generally characterized by the appearance of gastrointestinal disorders including abdominal cramps, nausea, diarrhea and/or vomiting which generally disappear after 24-48 hours.

Neurological manifestations can appear during these first hours (itching, headache, paresthesia, dysesthesia, etc.). A burning sensation or urogenital pain are also observed in some cases, from the first days.

On the cardiovascular level, cases of hypotension, bradycardia, changes in the T wave and, more rarely, tachycardia can occur from the first 24 to 48 hours.These attacks are generally associated with severe forms of intoxication.

Ciguatera does NOT cause FEVER. On the contrary, it may happen that during the first 24-48 hours following the poisoning, the patient presents a slight hypothermia, accompanied by chills.



Digestive disorders subside quickly, either spontaneously or in response to treatment.

A “STATE PHASE”, marked by the onset of pronounced rheumatological, general and neurological symptoms, such as parasthesia (tingling in extremities and the orofacial region) accompanied by dysesthesia and/or cold allodynia (causing burning sensations in contact with cold objects or liquid) is observed.

Unlike gastrointestinal symptoms, neurological symptoms may last for several weeks, months or even years.

Pruritis, dizziness, parasthesia, dysesthesia, ataxia, generalized weakness and mood disorders (i.e. depression…) are known to last for a longer period.




In addition to the main symptoms listed above, a generalized weakness evoking the Chronic Fatigue Syndrome (CFS) is also commonly reported in endemic ciguatera areas. This persistent weakness, is proposed as an explanation for the depressive tendencies observed in some patients, without excluding the possibility of a direct action of ciguatoxins on the central nervous system.




Chronology of appearance and degree of discomfort of the clinical signs observed in ciguatera poisoning



Ciguatera "Symptomatic treshold"


It may happen that, after sharing the same meal, only some persons develop the symptoms of the poisoning. This phenomenon can be illustrated with the theory of “the straw that broke the camel’s back”:


Chronic consumers of marine products from ciguatera-endemic areas accumulate small amounts of ciguatoxins in their bodies throughout their lives. CTXs are then redistributed and stored in different organs and tissues (fat cells and muscles specifically, due to the highly lipophilic nature of ciguatoxins).

Toxins content is therefore likely to vary from one individual to another, depending on their dietary habits.


It is only when the individual “symptomatic threshold” is reached that the symptoms appear.


The level of this threshold is estimated around 0.1 ng of toxins/g. of flesh.








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