The lychee, a popular and tasty tropical fruit that’s common in many Asian countries, has recently been identified as the culprit behind the deaths of over 100 children in India.
The investigation began about three years ago, when health officials sought to finally solve the mysterious deaths that have been plaguing a region of Muzaffarpur, India for over 20 years. In this region, around mid-May, panicked parents showed up at hospitals with sickened children. The children, they reported, were seemingly healthy, but had woken up in the night screaming. The children then suffered seizures and slipped into comas. The fatality rate was an alarming 40 percent.
“It was a very intense situation, because we witnessed children dying in front of our eyes every day, as soon as they arrived at the hospital,” said Dr. Rajesh Yadav, the lead investigator. Of the parents, Dr. Yadav said, “They were in a kind of panic. Their children were dying, and it was an unknown thing.”
The deaths were mysterious in more ways than one. For instance, there was no evidence that the children were infected with any pathogens. In particular, the children had no signs of fever or elevated white blood count - hallmarks of infections. Furthermore, the deaths seemed to be isolated. That is, within a single household, siblings were usually not affected. This supported a culprit other than a contagious pathogen.
Over the span of three years, Dr. Yadav observed several important clues in the affected children. The first involved the low blood sugar levels in the children. Some of the affected had severely glucose levels, and those children were more than twice as likely to die. “It seemed to be a little signal,” said Padmini Srikantiah, a CDC epidemiologist and the study’s senior author. “One of the things we heard multiple times from the children’s mothers was that they didn’t really eat dinner properly.”
The team also drew crucial information from similar cases in the Caribbean, where children were also stricken with convulsions and brain swelling. In the Caribbean cases, the cause was attributed to consumption of the ackee fruit. This fruit contains hypoglycin, a toxin that inhibits glucose production.
The ackee fruit is not found in Muzaffarpur, India. But this region is known for producing abundant lychees.
Indeed, when the team tested lychees for hypoglycin, they found their smoking gun. As it turns out, many of the affected children were poor and consumed lychees on an empty stomach. With their glucose levels already low, the hypoglycin in lychees worsened the hypoglycemia. The children woke up in the night screaming because of acute brain swelling, and the seizures and comas are also because of hypoglycemia.
Once the cause was established, parents were educated on prevention and doctors were educated on treatment methods. The authors report that with these measures, the death toll dropped from hundreds of deaths per year to about 50 per year. The mystery, it seems, has been solved.