Exposure to pesticides and other agrochemicals sprayed on trees in lychee orchards has been linked to an outbreak of acute encephalitis syndrome (AES) in northern Bangladesh in 2012, according to a study in the American Journal of Tropical Medicine and Hygiene carried out by a collaborative team of clinicians, epidemiologists, and social scientists from Bangladesh and the United States.

The leading hypothesized cause of AES among children living near lychee orchards was the ingestion of phytotoxins present in lychee seeds and pulp. However, recurrent AES outbreaks reported around lychee orchards, particularly around harvest season, and the short duration between onset of illness to death led the scientists to suspect toxic poisoning rather than infection or lychee ingestion.

一项合作小组在《美国热带医学与卫生杂志》上进行的一项研究显示，2012年孟加拉国北部，荔枝果园树木上喷洒的农药和其他农用化学品的暴露与急性脑炎综合征（AES）的爆发有关。来自孟加拉国和美国的临床医生，流行病学家和社会科学家。

在荔枝果园附近生活的儿童中，导致AES的主要假设原因是摄取了荔枝种子和果肉中存在的植物毒素。但是，据报道在荔枝果园周围，尤其是在收获季节前后，再次出现AES爆发，而且疾病发作至死亡之间的时间很短，这使科学家们怀疑是有毒的中毒，而不是感染或摄入荔枝。