UNB, Dhaka :
Excessive and improper applications of insecticides and other agriculture chemicals in local fruit orchards may have caused an outbreak of a deadly swelling of the brain, known as acute encephalitis syndrome (AES), that killed 13 children in Dinajur in 2012, according to a new study.
All of the deaths, which occurred within 20 hours of the onset of symptoms, were linked to exposure to lychee, a small, reddish fruit with a sweet white flesh that is cultivated across China and South Asia.
As of 2016, Bangladesh was one of several countries, including the United States, that still allowed restricted use of endosulfan. The pesticide was slated to be phased out of use in the USA by the end of 2016, according to the report UNB received from icddr,b on Tuesday which was published online in the American Journal of Tropical Medicine and Hygiene.
Similar deaths from AES have been observed near lychee orchards in India. However, a recent analysis published in the journal The Lancet concluded that those deaths were caused by a reaction to a
naturally occurring toxin found in lychee seeds and pulp.
“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 anexposure to multiple, highly toxic agrochemicals,” said M Saiful Islam, an Associate Scientist at the International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b) 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.” Saiful Islam and colleagues from icddr,b, the Institute of Epidemiology, Disease Control and Research (IEDCR) and the United States Centers for Disease Control and Prevention(CDC) based their conclusion on an exhaustive investigation into 14 cases of AES in children 1 to 12 years old that occurred between May 31 and June 30, 2012. Only one child survived.
The scientists discovered that around the 2012 outbreak, growers wereapplying endosulfan in the orchards, which, the study notes, is a “highly toxic” insecticide that has been banned due to the deleterious health effects in more than 80 countries.
According to the study, 13 of the 14 children lived either right beside or within 10 meters of a lychee orchard. One victim did not live as close to an orchard, but, before falling ill, he reportedly consumed a large number of lychees collected from the same orchards.
Local residents told the investigators that it was common for children to play in the orchards and to eat fruit that had fallen on the ground without washing it, using their teeth to peel the lychee’s tough skin.
In addition, several of the victims had family members who worked in the orchards, which, the study notes, could have increased exposures via residues on clothing worn into the home.
Several families of victims reported the symptoms began with a sharp, sudden cry from their child. Loss of consciousness occurred, on average, about 2.5 hours after the onset of illness and deaths within about 20 hours or less.
Other symptoms included respiratory distress, froth at the mouth and convulsions. While it is known that an infection like meningitis can lead to AES, the scientists asserted 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.”
Saiful said physical evidence collected from the orchards, which included discarded containers of insecticides and other chemicals, and interviews with community residentssuggested that multiple chemicals were applied to the fruit and in amounts far greater than are normally used by other lychee producers.
The study also found evidence that the lychee growers were applying an insecticide that had been approved only for use in cotton, not food crops.
The researchers also noted that clinical symptoms seen in the children were similar to what was noted in an outbreak of sudden child deaths in 2009 in Bangladesh that was linked to the carbamate class of insecticides, which were also used in the lychee orchards.
Excessive and improper applications of insecticides and other agriculture chemicals in local fruit orchards may have caused an outbreak of a deadly swelling of the brain, known as acute encephalitis syndrome (AES), that killed 13 children in Dinajur in 2012, according to a new study.
All of the deaths, which occurred within 20 hours of the onset of symptoms, were linked to exposure to lychee, a small, reddish fruit with a sweet white flesh that is cultivated across China and South Asia.
As of 2016, Bangladesh was one of several countries, including the United States, that still allowed restricted use of endosulfan. The pesticide was slated to be phased out of use in the USA by the end of 2016, according to the report UNB received from icddr,b on Tuesday which was published online in the American Journal of Tropical Medicine and Hygiene.
Similar deaths from AES have been observed near lychee orchards in India. However, a recent analysis published in the journal The Lancet concluded that those deaths were caused by a reaction to a
naturally occurring toxin found in lychee seeds and pulp.
“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 anexposure to multiple, highly toxic agrochemicals,” said M Saiful Islam, an Associate Scientist at the International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b) 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.” Saiful Islam and colleagues from icddr,b, the Institute of Epidemiology, Disease Control and Research (IEDCR) and the United States Centers for Disease Control and Prevention(CDC) based their conclusion on an exhaustive investigation into 14 cases of AES in children 1 to 12 years old that occurred between May 31 and June 30, 2012. Only one child survived.
The scientists discovered that around the 2012 outbreak, growers wereapplying endosulfan in the orchards, which, the study notes, is a “highly toxic” insecticide that has been banned due to the deleterious health effects in more than 80 countries.
According to the study, 13 of the 14 children lived either right beside or within 10 meters of a lychee orchard. One victim did not live as close to an orchard, but, before falling ill, he reportedly consumed a large number of lychees collected from the same orchards.
Local residents told the investigators that it was common for children to play in the orchards and to eat fruit that had fallen on the ground without washing it, using their teeth to peel the lychee’s tough skin.
In addition, several of the victims had family members who worked in the orchards, which, the study notes, could have increased exposures via residues on clothing worn into the home.
Several families of victims reported the symptoms began with a sharp, sudden cry from their child. Loss of consciousness occurred, on average, about 2.5 hours after the onset of illness and deaths within about 20 hours or less.
Other symptoms included respiratory distress, froth at the mouth and convulsions. While it is known that an infection like meningitis can lead to AES, the scientists asserted 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.”
Saiful said physical evidence collected from the orchards, which included discarded containers of insecticides and other chemicals, and interviews with community residentssuggested that multiple chemicals were applied to the fruit and in amounts far greater than are normally used by other lychee producers.
The study also found evidence that the lychee growers were applying an insecticide that had been approved only for use in cotton, not food crops.
The researchers also noted that clinical symptoms seen in the children were similar to what was noted in an outbreak of sudden child deaths in 2009 in Bangladesh that was linked to the carbamate class of insecticides, which were also used in the lychee orchards.
