Case Report: Paralytic Shellfish Poisoning in Sabah, Malaysia

Area of Science:

• Marine Biology
• Toxicology
• Public Health

Background:

• Red tide events, characterized by blooms of toxic dinoflagellates like *Pyrodinium bahamense* var. *compressum*, pose significant risks to marine ecosystems and human health.
• Paralytic Shellfish Poisoning (PSP) is a serious public health concern associated with the consumption of contaminated seafood.

Observation:

• During January-February and May-June 2013, Kota Kinabalu, Sabah, experienced red tide occurrences.
• Six PSP episodes affected 58 individuals, resulting in four fatalities, primarily from consuming contaminated shellfish from markets and beaches.
• High levels of saxitoxin (STX) were detected in shellfish, with mean concentrations reaching 2,920 ± 780 µg STX eq/100g.
• Elevated counts of *Pyrodinium bahamense* var. *compressum* (mean 34,200 ± 10,300 cells/L) were recorded in coastal waters.

Findings:

• The primary shellfish species implicated in STX accumulation were *Atrina fragilis*, *Perna viridis*, and *Crassostrea belcheri*.
• Victims, aged 9 to 67, exhibited classic PSP symptoms including dizziness, numbness, vomiting, and respiratory distress.
• The study confirms a direct correlation between red tide events, high STX levels in shellfish, and subsequent human poisonings.

Implications:

• Enhanced monitoring systems for red tide occurrences and shellfish toxicity are essential for early warning.
• Public health advisories and educational campaigns targeting coastal communities, fishermen, and fishmongers are critical to mitigate PSP risks.
• Regular surveillance of STX levels in commercially important shellfish species should be implemented to ensure seafood safety.