The horseshoe crab (Carcinoscorpius rotundicauda) is consumed by those
residing near the coastal areas of Kota Marudu District in Malaysia, as it is considered
a delicacy. During June to August, 2011 thirty cases of tetrodotoxin poisoning
were reported from Kota Marudu District following ingestion of horseshoe
crabs caught in Kota Marudu Bay. The purpose of this study is to describe this
case series in order to determine risk factors to prevent further outbreaks. There
were six confirmed and 24 probable cases of tetrodotoxin poisoning identified in
the study area during the study period as diagnosed by clinical presentation and
laboratory findings. Symptoms included dizziness (80%), circumoral and lingual
numbness (80%), hand and feet numbness (63.3%), nausea and vomiting (30%)
and weakness and difficulty in breathing (26.6%). Three cases (10%) died while 27
cases recovered. Forty-seven percent of the cases had onset of symptoms within
30 minutes of ingestion and 14% 31-60 minutes after ingestion of horseshoe crab
meat. Urine samples were collected from the cases, while horseshoe crabs, cockles
and sea water from the epidemic area were also taken for analysis. Tetrodotoxin
was detected in the urine of six cases; the highest concentrations recorded were
among the three cases who died. High tetrodotoxin concentrations were found
in the hepatic cecum and eggs of the tested horseshoe crabs. Dinoflagellates were
not detected in the sea water or cockle samples. Intensive health education was
initiated quickly to stop other members of the Marudu Bay community from
consuming the horseshoe crabs. This is the first documented epidemic of tetrodotoxin
poisoning in Sabah.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.