For several years, a mysterious outbreak would cause hundreds of children to fall ill in the town of Muzaffarpur, a place in the state of Bihar, India. The children would experience seizures, altered mental states and went into comatose states and about 40% of them would die – and no one could explain why.
This outbreak was a recurring phenomenon that would begin each year in mid-May and peak in June, coinciding with the lychee harvesting season, for which Muzzafarpur was famous for. After all, it is India’s largest lychee farming region, accounting for 70% of the country’s lychee harvest.
This intrigued the scientists and in 2014, doctors at India’s National Center for Disease Control and the American Centers for Disease Control and Prevention embarked on a study to identify the culprit behind the mystery disease.
Findings from that investigation, published on January 31st in the leading medical journal The Lancet Global Health, have, for the first time, comprehensively confirmed that this illness is associated with lychee fruit consumption and the effects of naturally occurring lychee toxins.
For the study, investigators looked at the hundreds of children admitted to local hospitals in 2014 with similar symptoms. Of the 390 children admitted, 122 died.
The children showed no signs of infection or elevated pesticide levels, however they were in for a surprise when they tested the blood glucose levels of the affected children. The glucose levels in the sick children were very low compared to kids who did not exhibit any disease symptoms.
“It seemed to be a little signal,” CDC epidemiologist Padmini Srikantiah told the The New York Times. “One of the things we heard multiple times from the children’s mothers was that they didn’t really eat dinner properly.”
Additionally, the researchers found high levels of hypoglycin A and methylenecyclopropyl glycine (MCPG) in two-thirds of the children’s urine, which are naturally-occurring toxins found in lychee fruit. This toxin prevents the body from making glucose, leading to a glucose-deficient state and causing “metabolic derangement”.
In the study, the parents reported that their kids would often frequent the neighbouring orchards and eat lychee fruit. They’d lose their appetite then and would not want to eat dinner.
Thus, the researchers concluded that “the synergistic combination of lychee consumption, a missed evening meal, and other potential factors such as poor nutritional status, eating a greater number of lychee, and as yet unidentified genetic differences might be needed to produce this illness.”
Based on the results of this collaborative investigation, public health recommendations that were targeted at preventing illness and reducing mortality were provided to state and national health authorities in India. The recommendations included minimizing lychee fruit consumption among young children in the affected area and ensuring that they received a proper meal. Incase of an illness, rapid assessment of blood glucose levels must be done. In the past year, the case of illness has gone down to less than 50 children due to these insights.
It is noteworthy that, the application of a comprehensive and systematic approach to investigating illness, including the key role of the CDC/NCDC-led India Epidemic Intelligence Service officers in the field, was critical to successfully identifying the etiology and risk factors for this illness, and led directly to recommendations to prevent illness and deaths from this outbreak.
Before you start panicking about the harmful effects of Lychee fruit, it must be remembered that Lychee fruit itself is not harmful. The only caveat is that it should not be taken on an empty stomach!