Ackee poisoning in Jamaica
Several plant species contain or produce toxic substances. It is believed that these naturally occurring toxins are produced as part of the plant's defence mechanism against predators. Many of these plants are a source of food in many countries.
Ackee, which is part of Jamaica's national dish, is one such plant. The word 'ackee' originated from the Twi language of Ghana. The plant, Blighia sapida, was introduced to Jamaica by Captain William Bligh in 1778. Coincidentally, it was the same Captain Bligh who took the breadfruit here. Ackee also grows in other islands such as Cuba, Haiti, Barbados and Hawaii. It is also known in South Florida and Central America.
Over the years, there has been an association between ackee poisoning and Jamaican vomiting sickness, which was first noted in 1875; however, documentation of these incidents did not begin until 1904. The toxic material is a water-soluble substance, which is found in the seeds and pods of the ackee fruit, called hypoglycin.
It is of interest to note that ackee-poisoning reports are usually received in the 'winter' months of the year and usually span from November to April. The majority of cases usually occur in the second to the fifth week of the year, after which it fluctuates and declines until it begins to increase again in weeks 48 to 51, near the end of the year.
For many years, there has not been documented reports of the true incidence of ackee poisoning nor of associated fatalities, neither internationally nor locally. Up to 2009, there were only two incidents of ackee poisoning reported in the United States.
Jamaica's Ministry of Health figures reveal 271 cases have been reported for the period 1980-2009. The most recent data from the National Surveillance Unit (NSU) in the health ministry showed they received reports of suspected ackee poisoning as detailed below:
ACKEE POISONING 2003-2013
YEAR # OF CASES
Source: Ministry of Health, Epidemiology,
Research and Data Analysis
From year to year, the parish distribution of suspected cases appears random. 2011 could be described as an outbreak year, with St Ann reporting the most cases (54). In 2012, Trelawny had the most cases (14), followed closely by Portland (13), while in 2013 Portland had the majority of the reported cases (10) followed by St James with six and Clarendon with five.
When analysed by age, most cases of poisoning and most cases of death, 68 per cent and 72 per cent, respectively, occurred in persons ranging from 15 to 54 years old in 2011. The most recent data available (2013) had persons ranging in age from 17 to 70 years old.
In 2011, with respect to fatalities from ackee poisoning, the NSU reviewed 28 of the 29 cases of death and 13 cases were classified as confirmed, six as probable and three were discarded. The latter were discarded as there was no evidence to support that they had eaten ackee.
In 2012, there were only two deaths attributed to ackee poisoning, and in 2013, there were three cases of deaths due to suspected ackee poisoning. It should be noted that these are still being investigated before being confirmed.
Up until 2010, health-care facilities, including hospitals, were not mandated to report ackee-poisoning cases on a routine basis to the Ministry of Health's NSU.
In 2011, because of the significant spike in the number of cases reported, ackee poisoning was made a Class 1 Notifiable Event, which made it a requirement in law for suspected ackee-poisoning cases to be reported to the NSU.
A review of the data for the period 2003 to 2013 reveals that between 2003 and 2007, the number of cases remained in single digits, ranging from two to six. In 2008, the figure increased to 14, declined to three in 2009 and rose again in 2010 to 29, with an alarming increase in 2011 to 320. In 2012, the figure again decreased to 80 and tapered to 47 in 2013.
There is a need for further studies to be done in order to explain the information in 2011 and to explore the possible linkage between poisonings and deaths to socio-economic status of the individuals affected.
Some questions to be considered are: Is there a correlation to poverty and or level of education? Should the Ministry of Agriculture and academia be collaborating to modify the ackee plant to produce a hypoglycin-free ackee? What is the reason for the dramatic reduction in 2012? What is the relationship between susceptibility to and severity of poisoning episode to the nutritional status of affected individuals?
Experience has shown that the key to avoid being poisoned lies in proper handling and preparation of meals containing ackee before it is consumed. Also, proper harvesting practices must be used. The relationship between the risk of ackee poisoning and
existing nutritional status of the individual should be determined and be communicated by the Ministry of Health.
It is hoped that the necessary follow-up action in terms of investigation and analysis will be undertaken by the relevant stakeholders, in particular the Ministry of Health, as it continues to play a lead role in solving the ackee poisoning mystery and ensuring the public's health and safety.
- Dr Mearle Barrett, PhD, is a pharmacist, toxicologist and also the co-chair of the Caribbean Poison Information Network (CARPIN) Education Subcommittee. Email: email@example.com