Jamaican vomiting sickness, also known as toxic hypoglycemic syndrome (THS),
acute ackee fruit intoxication, or ackee poisoning,
is an acute illness caused by the toxins
hypoglycin A and
hypoglycin B, which are present in fruit of the
ackee tree. While in the fully ripened
arils, hypoglycin A is at levels of less than 0.1 ppm, in unripe arils it can be over 1000 ppm
[Medscape- Toxicity, Plants - Ackee Fruit]
/ref> and can cause vomiting and even death. Some countries in the Caribbean and Western Africa experience frequent cases.
Presentation
Abdominal discomfort begins two to six hours after eating unripe ackee fruit, followed by sudden onset vomiting. In severe cases, profound dehydration, seizures, coma, and death may ensue. Children and those who are malnourished are more susceptible to the disease.
Pathophysiology
When ingested, hypoglycin A is metabolized to produce methylenecyclopropylacetic acid (MCPA). MCPA acts to inhibit the beta-oxidation of fatty acids in two ways. First, it interferes with the transport of long-chain fatty acids into the mitochondria. Also, it inhibits acyl-CoA dehydrogenases, so that only unsaturated fatty acids can be fully oxidized. Fatty acids accumulate in the liver in a microvesicular pattern that can be seen on biopsy. In the absence of fatty acid metabolism, the body becomes dependent on glucose and glycogen for energy. Octreotide
Octreotide, sold under the brand name Sandostatin among others, is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone. It was ...
can be used to reduce the secretion of insulin by the pancreas, thereby preventing severe hypoglycemia
Hypoglycemia, also called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose bel ...
.
Inhibition of beta-oxidation of fatty acids, however, also depletes a necessary cofactor for gluconeogenesis. Once the liver glycogen stores are depleted, the body cannot synthesize glucose, and severe hypoglycemia results.
Initial symptoms appear after about four hours, and deaths have been reported from 12 to 48 hours following consumption. Supportive care involves carefully metered IV glucose infusion and fluid/eletrolyte replacement; Mortality was 80% before glucose infusion was introduced in 1954.
A similar outbreak of lethal hypoglycemic encephalopathy
Encephalopathy (; from grc, ἐνκέφαλος "brain" + πάθος "suffering") means any disorder or disease of the brain, especially chronic degenerative conditions. In modern usage, encephalopathy does not refer to a single disease, but r ...
has been linked to the consumption of lychee
Lychee (US: ; UK: ; ''Litchi chinensis''; ) is a monotypic taxon and the sole member in the genus ''Litchi'' in the soapberry family, ''Sapindaceae''.
It is a tropical tree native to Southeast and Southwest China (the Guangdong, Fujian, Yun ...
fruit in Muzaffarpur, India. Urinalysis
Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic ...
of children affected by the disease has shown all affected have elevated levels of hypoglycin suggesting the same underlying pathophysiology as Jamaican vomiting sickness.
Diagnosis
In popular culture
The disease appears in the ER episode " Great Expectations", where the symptoms are recognised by Dr Mallucci who, it is later revealed, attended medical school in Grenada.
See also
* Reye syndrome
Reye syndrome is a rapidly worsening brain disease. Symptoms of Reye syndrome may include vomiting, personality changes, confusion, seizures, and loss of consciousness. While liver toxicity typically occurs in the syndrome, jaundice usuall ...
* Methylene cyclopropyl acetic acid
References
Toxic effect of noxious substances eaten as food
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