Figure 1: Fruit of the ackee tree
-from Epidemiological Bulletin, Vol. 22 No. 2, June 2001-
Between November 2000 and March 2001, 80 cases of an acute phenomenon were registered in two communes (districts) of Haiti’s Northern province. The illness was characterized by continuous vomiting, abdominal pains, loss of consciousness, convulsions and death in the most serious cases.
The nature of the symptoms and past history of similar conditions in the same region in 1988 and 1991 suggest that this phenomenon was caused by consumption of ackee (Blighia sapida), a common fruit in the region that produces serious health effects when consumed unripe.
Ackee is the national fruit of Jamaica and was imported from West Africa in the 18th century. It is a tall, leafy tree (up to 12 meters) that produces clusters of fruits widely used for human consumption and for industrial purposes. The tree is found in several countries in the World and in the Region of the Americas, where it is known under various names, such as “Arbre à fricasser” in Haiti, “yeux de crabe” or “ris de veau” in Martinique, “fruto de huevo” in Panama and Guatemala, “árbol de seso” in Cuba, “merey del diablo” in Venezuela, “pan y quesito” in Colombia, or “pero roja” in Mexico. The tree produces fruit twice a year, between January and March and between June and August. The fruit is yellow in color and shaped like an oblong capsule that contains three cream-colored arils (figure 1). The arils may be consumed safely when the fruit becomes red and opens under the light of the sun. It is then commonly boiled in water or milk and eaten alone or in meat or fish dishes. It is also consumed raw in some African countries. When ingested unripe, ackee produces vomiting and fatal cases of poisoning.
Figure 1: Fruit of the ackee tree |
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The toxic health effects are produced by hypoglycins A and B, which have a potent hypoglycemic effect causing the clinical symptoms and death. The most toxic is hypoglycin A, which is found in the unripe arils. Hypoglycin A is a water-soluble liver toxin that produces hypoglycemia through the inhibition of gluconeogenesis, secondary to the limitation of cofactors (CoA and carnitine) that are essential for the oxidation of long-chain fatty acids. The concentration of Hypoglycin A in the unripe ackee is 20 times greater than in the mature fruit, however the level of concentration of the toxin lowers rapidly after its exposure to the sun. The seeds contain hypoglycin B and are always poisonous. An important factor seems to be the nutritional status of the person consuming ackee, since diagnosed patients often present chronic malnutrition and vitamin deficiencies.
Ackee trees proliferate in Haiti, especially in the Northern province. This area has a population of approximately 824,000 people distributed in 19 communes. The cases of ackee poisoning were registered in the communes of Milot and Plaine du Nord, which were affected by intense rains for a period of 10 days in November 2000. This weather condition resulted in floods that affected more than 25,000 families and produced considerable losses in corn and sugar cane production, on which the economy of the region relies heavily. This natural phenomenon worsened the living conditions of a population already characterized by levels of extreme poverty.
It is important to point out that due to the characteristics of the epidemiological surveillance system in the country, which is neither representative nor sensitive or timely, the registration of cases was not complete, especially between November and January. The epidemiological alarm was initiated in February, when a team from the central Ministry of Public Health and Population (MSPP for its French name “Ministère de la Santé Publique et de la Population”) carried out an evaluation and intervention visit.
The report indicated that in the month of February alone, 73 deaths had been registered in the two communes. The main victims were children under 15 (90%), who presented an acute clinical picture characterized by a sudden onset of abdominal pains, uncontrollable vomiting, loss of consciousness, convulsions and death within 24 hours of the first symptoms. Earlier ackee consumption was found in some of the cases that were investigated, but review of available clinical histories revealed the presence of other associated diseases, such as diabetes and tuberculosis, making it difficult to attribute with certainty the 73 deaths to ackee consumption. The report also indicated that during field visits, stomatitis and skin injuries were observed in children, a sign that the population - especially the young - showed signs of malnutrition and avitaminosis.
The team visited the affected communes and met with the local authorities as well as with the media to inform the population about the risks associated with the consumption of unripe ackee fruits and prevent more cases of poisoning. Press interviews of health authorities from the Northern Province and the central level were widely disseminated by radio, newspaper, and television.
A second research team, composed of representatives from the United States Centers for Disease Control and Prevention (CDC), epidemiologists from the MSPP, and PAHO professionals, was sent to the Northern Province during the first week of March.
On this occasion, a total of 46 cases were identified retrospectively using a rather sensitive case definition, and applying a questionnaire to identify the risk factors. Blood and urine samples were collected whenever possible, and organ samples were harvested from a patient on which a necropsy was performed. Consumption of ackee was confirmed in 69% of these 46 cases. The ages of the victims ranged between 6 months and 88 years, with a median of 7 and an average of 16. Men represented 38% of the cases. The case-fatality rate was 52%.
No additional cases were registered since 8 March, which coincides with the end of the year’s first fruit season. The exact number of cases cannot be accurately specified. However, it is very probable that the deaths, especially those that occurred in less than 12 to 24 hours in children under age 10, were due to the consumption of Ackee in poor and famished populations.
Recommendations included strengthening the epidemiological surveillance system, with community participation, as well as education, communication, and information activities for the population in order to avoid further consumption of the unripe fruit.
References
(1) Hecdivert C, Sainvil MS, Desormeaux AM. Investigation d’un phénomène morbide dans les communes de Plaine du Nord et de Milot. Port-au-Prince, Haiti; 2000. (Unpublished document).
(2) University of the West Indies, Mona. Available at: http://wwwchem.uwimona.edu.jm:1104/lectures/ackee/html
(3) The ackee Pod. Available at: www.ackee.com
(4) Ministère de la Santé Publique et de la Population, OPS, UNICEF. Rapport de l’évaluation sur la situation épidémiologique post-inondation dans le nord. No place; 2000. (Unpublished document)
(5) CDC. Toxic Hypoglycemic Syndrome - Jamaica 1989-1991. MMWR January 31, 1992 / 41(04);53-55
(6) Institut de Recherche pour le Développement, Guayana Francesa. Disponible a: http://www.cayenne.orstom.fr/laboratoires/web_elodie/fiches.plant/blighia.html (7) Albion College, USA. Available at: http://www.albion.edu/plants/bligsafr.htm
Source: Prepared by Dr. José Moya of the PAHO/WHO Representation in Haiti.
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Epidemiological Bulletin, Vol. 22 No. 2, June 2001