Methylenecyclopropyl glycine, not pesticide exposure as the primary etiological factor underlying hypoglycemic encephalopathy in Muzaffarpur, India.

Some districts of Bihar, especially Muzzaffarpur district, have been known to be affected by annual outbreak, called locally as Acute Encephalitis Syndrome (AES) which became one of the major health concerns in Bihar, due to its high fatality and complications. Several hypotheses like bat virus, heat stroke, pesticide exposure and the presence of a compound - methylenecyclopropyl glycine (MCPG) in Litchi have been proposed by different investigators for AES. When the investigators examined the symptoms, signs and the epidemiological data, bat virus and heat stroke hypothesis were ruled out. Two major hypotheses which remain in question were the exposure to pesticides or MCPG present in litchi. Therefore, this study was designed to check the presence of both in the Muzzaffarpur samples of ripe and semi ripe litchi fruits. The fruit cover of ripe and semi ripe litchi showed the traces of Malathion (0.18-0.19 μg/g) and p'-p'-DDT (0.022-0.023 μg/g), while no pesticide residues were detected in the pulp of ripe or semi ripe litchi thereby ruling out the possibility of pesticide exposure in children of Muzzaffarpur. However, MCPG was detected in the pulp of semi ripe (0.57 μg/g) and ripe litchi fruits (0.19 μg/g). Further, when the human condition was simulated in animals, there was deprivation in body weight and glucose levels in starved litchi seed dosed rats, causing hypoglycemia. These results suggest that the cause of hypoglycemic encephalopathy in Muzzaffarpur is related to the consumption of semi ripe and ripe litchi fruits by undernourished children.