The Centre for Disease Control in US would conduct a study to assess relation, if any, between nutritional imbalance and side effects of immunisation in children, who fall sick because of viral infection, which causes acute encephalitis-like syndrome.

This is being done after earlier efforts of several central teams probing to identify the virus, which causes symptoms of AES, did not bear much fruit.

AES has so far claimed hundreds of lives in north Bihar and it hits the area during peak summer.

Sources said the US team was collecting data on two points - nutritional imbalance and immunisation - to find out whether or not lack of nutrition and absence of immunisation had any co-relation with AES cases.

In this new endeavour of line of investigation, two scientists of the US agency led by Dr Shoran Davis and Dr Padmini made a whirlwind inspection of AES-affected hamlets in Mushahri, Kanti and Minapur blocks of the district from May 9 to May 12.