EOSINOPHILIC MENINGOENCEPHALITIS CAUSED BY ANGIOSTRONGULIASIS IN THAILAND

Autopsy of a 28 year old Thai woman who died with eosinophilic meningoencephalitis revealed 5 worms in 4 of 10 blocks of brain tissue taken for routine microscopic examination. Small areas of disrupted brain tissue containing necrotic tissue debris and scattered inflammatory cells, mostly histiocytes and neutrophils were interpreted as tracks of the moving worm. The worms were identified as Angiostrongylus, probably A. cantonensis. Three of the worms apparently dead in the tissues for some days before fixation were encased in a dense exudate and surrounded by a granulomatous reaction, whereas worms with well preserved tissues and apparently alive at the time of autopsy were free in the tissues. The presence of large numbers of Charcot-Leyden crystals in meninges indicated a massive response by eosinophils to the dead parasites. In addition, vascular congestion was a prominent feature.