Is it just the litchi that is killing Bihar's kids?

Since yesterday, I have been reading about the news articles stating consumption of litchi might be the cause of Acute Encephalitis Syndrome [AES] in children from Muzaffarpur district of Bihar. The articles were written referring to the latest paper published in The Lancet Global Health. The disease was attributed to two substances present in litchi fruit:

1. Hypoglycin A 
2.  methylenecyclopropylglycine[MCPG] which is chemically similar to hypoglycine A

These substances can inhibit the conversion of fat into glucose which takes place continuously in our bodies. As a result the blood glucose level drops and causes other problems consequently. The major conclusions of the study were:

• It was 9.6 times likely that that a suffering child had eaten litchi.

• It was 2.2 times likely that the ill child did not have evening meal.

• It was 7.8 times likely that the child ate litchi without an evening meal.

So far so good, but in the end, the paper claims that the disease occurrence might not be linked with socioeconomic status of the child (its family) stating casually the "homogeneity observed throughout the 16 blocks of Muzaffarpur district". Well, this might be a lame statement to make considering the reputation of lancet. One can understand the view as seen from Delhi and USA, however, if we search a little bit on google scholar, there is more that was found than just the litchi.

The was another paper published in July, 2016 that tested the same hypothesis. Strangely, this paper was not cited in lancet. Interestingly, the patients studied were from the same two hospitals of Muzaffarpur. May be there are only two main hospitals there. Though published in a lesser known journal, this study had better controls than the lancet article. 4 controls for each patient with varying closeness to the patient rather than just fellow patients without the AES. Following were their findings:

•  3.3 times likely that suffering child had eaten litchi.
• 2.03 times likely that their parents were illiterate.
•  2.3 times likely that their parents' occupation was agriculture.
• 2.1 times likely that they belonged to SC/ST category.
•  1.91 times likely to be OBC

It is most likely true that litchi consumption made the kids ill, but more importantly, the nutritional status of the kids might have made them more vulnerable to the substances present in litchi. From the odds stated above, the kids of agricultural labourers were the victims of the toxic compounds. Undernourishment is a common thing in poor households and there is no need to tell, how in India the wealth is distributed based on castes.

What I here want to emphasize is undernourishment in kids make them vulnerable to many substances or environments. India has come a long way from a famine prone country to the one who produces enough food for the masses. Our focus should be now to enable all people to afford that food irrespective of social or economic status.

Lastly, I hope at least the scientific community should become impartial (also be critical) towards previously published studies with competing interests.

P.S.: Only the statistically significant factors have been mentioned. Factors like hand washing had confidence intervals too wide to be relevant.