Muzaffarpur in Bihar had witnessed hundreds of mysterious deaths every year till 2014. The unexplained neurological illness that had claimed mostly the lives of malnourished children has been decoded by a group of scientists from the US and India. After a joint investigation, they have concluded that the illness and deaths were triggered by litchi — a tropical fruit found in Muzaffarpur — when consumed on an empty stomach.
The mysterious illness characterised by acute seizures and changed mental status has been afflicting Muzaffarpur for more than two decades. Reports of the same illness also surfaced from Malda district of West Bengal.
As the temperature soared sky-high every year in mid-May, parents took their children to hospitals, although they had been healthy the night before. In the morning, the children would wake up crying and have seizures, often slipping into comas. The cases would be at their highest in June and have been reportedly happening since 1995.
The reason behind the deaths
The researchers have found that presence of Methylene cyclopropyl-glycine (MCPG) and other chemicals in the litchi caused hypoglycemic encephalopathy when the blood sugar levels are low due to fasting or undernourishment. Earlier, encephalitis, heat stroke, infections carried by rats, bats or sand flies were suspected to be causing the deaths. The research has been published in the latest issue of The Lancet.
In 2013, the National Centre for Disease Control (NCDC) in India and the US Center for Disease Control (CDC) conducted laboratory investigations to find out about the potential infectious and noninfectious causes in 390 children who were admitted to two different hospitals in Muzaffarpur with certain neurological diseases. Out of the 390, 122 had died; 204 had low blood glucose during their admission. On questioning the parents, they said most of the children had consumed litchis and had missed the evening meal the previous day. The children who were most affected were those who stayed close to litchi orchards and consumed the fruits regularly on an empty stomach. They would spend the day eating the fruit and not eat dinner and other solid food.
While it is known that the seeds of litchi have MCPG, this study has shown that even the flesh has it as well.
“This study, to the best of our knowledge, is the largest investigation of the Muzaffarpur outbreak and the first comprehensive confirmation that this recurring outbreak illness is associated with litchi consumption and toxicity from both hypoglycin A and MPCG. We confirm the presence of MPCG and hypoglycin in litchis, and, for the first time, our data shows the metabolites of these toxins in human biological specimens, the biological impact of these toxins on human metabolism, and the modifying effect of the lack of an evening meal of the impact of these toxins,” scientists report in the Lancet study.
It must be remembered that litchis should not be consumed on an empty stomach or when one’s blood sugar levels are already low.