(CN) – The sudden deaths of 13 children in a remote village in Bangladesh was caused by exposure to a routinely used pesticide applied in a nearby lychee tree orchard, according to a scientific report released Monday.
The study published in American Journal of Tropical Medicine and Hygiene shed light on a mystery occurring in 2012, where 13 children all died of swelling of the brain called acute encephalitis syndrome.
Officials attributed the deaths to lychee seeds, which contain toxins, and they noted the deaths of small children throughout India and Asia who had been exposed to the fruit.
However, the recent study says excessive and improper application of insecticides to a lychee orchard near where the children lived and played is the actual culprit.
“Our investigation suggested the seeds might not be the cause, as the seeds are not eaten in Bangladesh, and instead found the deaths in 2012 were most likely due to an exposure to multiple, highly toxic agrochemicals,” said M. Saiful Islam, a scientist at the International Center for Diarrheal Disease Research and the lead author of the study. “These deaths occurred at a time when lychee was being harvested and consumed across Bangladesh. If the seeds were the cause, then we would expect to see cases scattered across the country, not just in a certain small area.”
Islam and other colleagues from Institute of Epidemiology, Disease Control and Research and the U.S. Centers for Disease Control and Prevention based their conclusion after exhaustive research into 14 cases of acute encephalitis syndrome affecting children in the Dinajpur district of Northern Bangladesh.
Only one child survived the outbreak, which occurred between May 31 and June 30, 2012. According to the study, 13 of the 14 children affected lived adjacent to or within 10 meters of the lychee orchard.
Through their research, the scientists discovered the orchard operators applied copious amounts of endosulfan prior to or during the outbreak. Endosulfan is an extremely toxic insecticide that has been banned in more than 80 countries.
Because of its tendency to bioaccumulate in wildlife that humans consume and its role as a hormone disruptor, a global ban of endosulfan was negotiated at the Stockholm Convention in 2011.
The United States has previously use of the toxic insecticide, but scheduled its complete phase-out as of 2016.
Many of the children who eventually succumbed to the outbreak reported consuming lychee from the orchard where the pesticide was used. Their parents almost uniformly reported hearing a sharp cry from the child, followed by a loss of consciousness within 2 1/2 hours and death within 20 hours.
The syndrome can be naturally occurring, caused by other diseases like meningitis, but the study concluded that the “short duration between onset of illness and death all suggest the outbreak was more likely due to a toxic poisoning than an infection.”
The researchers also used physical evidence, including empty insecticide cans, along with testimony from neighbors and other residents to determine a profuse amount of different insecticides were applied to the lychee orchard in amounts far exceeding typical practices.
“People in the communities told us that sometimes the spraying was so heavy it became difficult to stay in their houses and that the smell would linger for hours,” Islam said.
The researchers have attempted to connect the episode to other similar outbreaks in Bangladesh that resulted in the premature deaths of multiple children.
“Community education and improved oversight of pesticide use will be needed to help reduce the risk of future tragedies,” said Dr. Patricia F. Walker, president of the American Journal of Tropical Medicine and Hygiene.