There has been a kit available (Cigua-Check) for around $30 that allows you to test three fish samples for the presence of ciguatera toxins but the company making it is currently back-ordered and is not accepting orders...
Which leaves us in the realm of taking one's chances and wishful thinking while keeping an eye out for such symptoms as...
- Tingling, numbness, or stinging sensations around mouth, hands, or feet
- Temperature reversal sensations (cold feels hot, hot feels cold)
- Body chills, itching, headaches, perspiration, or dizziness
- Muscle pains, weakness, cramps or joint aches
- Vomiting or diarrhea
Which I am sure comes as good news to the grouper in question!