Tropical Diseases/Chapter 47
Section VII.— ACKEE POISONING
CHAPTER XLVII
THE VOMITING SICKNESS OF JAMAICA
AN acute and very fatal condition locally termed " the vomiting sickness " has been known for many years in Jamaica. It is found principally in rural districts and occurring in what were regarded as circumscribed epidemics. Until quite recently its causation and nature were neither apprehended nor understood, although several Commissions had attempted their elucidation. To Dr. Harold Scott belongs the merit of clearing up the mystery, and indicating simple and practicable methods of prevention, which, if given effect to, must avert a considerable mortality, particularly among children.
The vomiting sickness is confined to the West India Islands, and practically to Jamaica, and occurs principally during the cooler months November to April.
Symptoms.— A previously healthy child suddenly complains of abdominal discomfort, vomits several times, and apparently recovers, perhaps falling asleep. Three or four hours later, vomiting— now of a cerebral type— recurs. Within a very short time, a few minutes perhaps, convulsions and coma supervene, and death follows on an average about twelve hours from the oncoming of the initial vomiting. The case-mortality amounts to 80-90 per cent. In those who recover, convalescence is complete in twenty-four hours.
During the attack the temperature is normal or subnormal, rarely rising to 101°; the pulse is 90 to 100; the respirations are 26 to 30, sometimes, as death approaches, being of the Cheyne-Stokes type. The pupils are slightly dilated and, until near the end, react to light, etc. Unless during the convulsive seizures, there is no muscular rigidity. Post-mortem examination reveals hyperæmia of viscera with a tendency to minute interstitial hæmorrhages, together with marked fatty changes, especially in the liver and the kidneys, and sometimes to a less degree in the pancreas and heart-muscle.
Etiology.— Scott has shown, on what must be regarded as convincing evidence— clinical, seasonal, epidemiological, and experimental— that the vomiting sickness is really the result of poisoning by a fruit, much used by negroes in Jamaica, called ackee, the fruit of Blighia sapida, a tree very common in the island. When mature and in good condition this fruit is wholesome enough, but if gathered before it is quite ripe and before it has opened while on the tree, or if gathered from an injured branch, or opened after falling on the ground, it is poisonous. It would appear that the poisonous element in the immature and unsound fruit is soluble in water, for the " pot water " in which the ackees have been cooked is much more toxic than the cooked fruit and, further, that the poison is precipitated by alcohol.
Treatment.— An emetic, and washing out the stomach with an alcoholic fluid during the primary vomiting, seem to be indicated.