Researchers have provided more details about an outbreak traced to contaminated food aid in Uganda in 2019 that killed five people.
It was the largest documented outbreak caused by food contamination with tropane alkaloids, according to the study published in the journal BMC Public Health.
Jimsonweed, also known as Datura stramonium, contains toxic alkaloids that cause gastrointestinal and central nervous system symptoms when ingested and can be lethal at high doses. The plant may grow together with certain crops and mix with them during harvesting. In March 2019, more than 200 patients were admitted to multiple health centers for acute gastrointestinal and neurologic symptoms.
Scientists reviewed medical records and canvassed all villages of the eight affected sub-counties to identify cases. In a retrospective cohort study in 17 villages that reported the earliest cases, researchers interviewed 211 residents about dietary history during March 11 to 15.
The team identified 293 suspected cases with five deaths. Symptoms included confusion, dizziness, diarrhea, nausea or vomiting, convulsions, and hallucinations. The outbreak started on March 12, two to 12 hours after a batch of fortified corn-soy blend (CSB +) was distributed by the World Food Programme (WFP). In the retrospective cohort study, 66 percent of 134 people who ate CSB +, compared with 2.2 percent of 75 who did not, developed illness.
Lab analysis results
Samples of the affected batch distributed from March 11 to 15 contained 14 tropane alkaloids, including atropine at 25 to 50 parts per million (ppm) and scopolamine at 1 to 10 ppm. Proteins of Solanaceae seeds and Jimsonweed DNA were identified.
Samples were shipped to Intertek in South Africa, Mérieux Nutrisciences in Italy, and the Center for Food Safety and Applied Nutrition (CFSAN) at the U.S. Food and Drug Administration. CFSAN identified atropine and scopolamine in samples. Levels of atropine and scopolamine were hundreds of times higher than the allowable limits set by the European Food Safety Authority (EFSA).
The outbreak occurred in the Napak and Amudat districts in the Karamoja region, Northeastern Uganda. In total, 215 cases were in Napak and 78 in Amudat. Four deaths were in Napak and one in Amudat. Two children, aged 2 and 10, died.
The high number of deaths could be because of multiple tropane alkaloids in the implicated batch, coupled with high prevalence of malnutrition among children in Karamoja, said researchers.
For most patients, symptoms resolved within 24 hours after treatment with intravenous fluids, activated charcoal, and sedatives. No antibiotics were given. Females were significantly more likely to be sick than males. Those under five years old were most affected.
The outbreak subsided after CSB + was withdrawn. However, some community members did not return the CSB + despite efforts by the WFP to withdraw the food. In late March and mid-April, two smaller outbreaks occurred after people started eating the CSB + that they did not return to WFP.
Two contracted companies transported the contaminated batch from a central distribution point in Tororo, Uganda, to Moroto, where the food was sent to health facilities. It was imported into Uganda from Mombasa, Kenya.
Records show this batch came from Turkey but researchers could not identify the precise location in the country where the CSB + was produced or how it was processed. Another study found deficiencies at the Turkish factory that supplied the implicated food aid.
Batch numbers were related to donation consignment and not production date, source of raw materials, or factory, which goes against documented best practice and packaging of CSB + lacked unique serial numbering.
Identification of proteins from Solanaceae seeds and isolation of DNA of jimsonweed in the batch pointed to contamination at harvesting and production stages because of failure of quality control along the supply chain, according to the study.
However, control CSB + samples from unaffected households and a central warehouse also contained low levels of atropine, indicating contamination could be widespread.
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