The World Food Program (WFP) has requested assistance from the FAO and WHO on tropane alkaloids after five people died in Uganda this past year from contaminated food aid.
The United Nations agency wanted the Food and Agriculture Organization (FAO) and World Health Organization (WHO) to provide scientific advice on tropane alkaloids in processed and unprocessed WFP products to allow development of risk management measures in the supply chain and prevent future outbreaks.
In April 2019, consumption of “Super Cereal” from a Turkish supplier was associated with five deaths and 300 peopled who needed hospital treatment in the Karamoja region of Uganda. An August outbreak in Palabek refugee settlement in the north of the country affected 33 people. This was caused by a bag of contaminated stock mistakenly being distributed.
FAO and WHO expert meeting
High concentrations of scopolamine and hyoscyamine, which are tropane alkaloids, from Datura stramonium, in soybeans were the source of intoxication. The WFP, the WHO, the government of Uganda, the U.S. Centers for Disease Control and Prevention, and U.S. Food and Drug Administration were involved in the investigation.
Another contamination incident in 2019 involved unprocessed sorghum contaminated with Datura stramonium seeds, which was distributed as food aid to South Sudan.
“Super Cereal” consists of pre-cooked corn, soybean and micronutrients. Approximately 130,000 metric tons (143,000 tons U.S.) are distributed to 4.9 million people every year to improve food security and nutrition.
The FAO and the WHO held a joint expert meeting on tropane alkaloids from March 30 to April 3. It was planned as a physical meeting at the FAO in Rome but was held remotely because of the COVID-19 pandemic.
There are no international regulations for tropane alkaloids in processed foods with no Codex maximum levels or a code of practice available for these contaminants.
Growing season conditions, growing location, plant maturity, species and variety, and type of plant tissue affect the concentration and proportion of hyoscyamine and scopolamine in samples, according to meeting participants.
Experts from the FAO and the WHO found the number of studies with data on the fate of tropane alkaloids during food processing was limited. Even in the few available, most did not consider effects from sample heterogeneity and changes in moisture content during processing or did not provide complete analytical method description.
Attendees agreed to assume there was no loss of hyoscyamine and scopolamine because of food processing for the dietary exposure assessments to maximize protection of consumers.
Contamination levels before and after
Data on the concentrations of hyoscyamine and scopolamine in Super Cereal (SC) and Super Cereal plus (SC+) processed before the poisoning and after were available.
Measures taken during this period included supplier monitoring of ingredients for tropane alkaloids, selection of specific raw material sources with low levels of tropane alkaloids and improved grain cleaning, to remove weed seeds.
An acute dietary exposure assessment was done for the sum of concentrations reported for hyoscyamine and scopolamine (referred to as tTA). Concentration data for four samples of SC that caused illness had mean and maximum tTA concentrations of 13,300 and 17,390 micrograms per kilogram (μg/kg), respectively.
For a SC consumption of 100 gram (3.5 ounces) and body weight of 60 kilograms (132 pounds), these concentrations would equate to exposure doses of 22 and 29 μg/kg of body weight, respectively. For young children of 15 kilograms (33 pounds) having 100 grams of product, the doses would be 89 µg/kg of body weight and 116 µg/kg of body weight.
A high proportion of samples analyzed contained hyoscyamine and/or scopolamine. It was considered likely by experts that all samples were contaminated but some at undetectable levels.
Mean concentrations of tTA in SC and SC+ before the incident were 12.8 and 14.5 μg/kg, respectively with max levels of 216 and 96 µg/kg. Afterwards, concentrations were 3.1 and 1.9 μg/kg with max levels of 8 and 8.7 µg/kg.
Before the incident, mean acute dietary tTA exposures for young children (SC+), children (SC) and women (SC) were 130, 45 and 26 nanograms per kilogram of body weight, respectively. After the outbreak and with added risk management measures, exposures for the three populations were 17, 11 and 6 ng/kg bw.
Based on recommended intake of the WFP products of 100 grams a day, a combined hyoscyamine and scopolamine concentration in dry food of less than 30 μg/kg (in SC) or 10 μg/kg (in SC+ and lipid-based nutrient supplements) should be safe for adults and children.
Concentrations are proposed as limits that may apply to other cereal and grain products when consumed in comparable quantities, according to the experts.
For emergency situations where food security is taken into consideration, guidance levels of 90 μg/kg (SC) and 30 ug/kg (SC+ and LNS) should still protect against severe toxicity for adults and children.
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