Abstract: 　Objective To make etiological and epidemiological investigation on the infection of Angiostrongylus canto-nensis in 8 pupils in Changle City. Methods (1) CSF of patients was examined with the conventional method to detect pathogens and eosinophiles. (2) The fecal samples of wild rodents were collected from the spot and examined microscopically to discover the first stage larvae of A. cantonensis. (3) Snails (Pila gigas) were collected in the spot. The smashed head tissue was examined for the third stage larvae of A. cantonensis. (4) The patient's clinical symptoms and physical signs were recorded with an emphasis on central nervous system. Results (1) Two larvae of the third stage of A. cantonensis were found in CSF of one patient. Eosinophiles occupied 68% of the cell number in average (ranged from 47% to 83%) in CSF of the 8 patients. (2) The infection rate of the first stage larvae of A. cantonensis was 39.3% (44/112) in feces of the rodents. (3) The infection rate of the third stage larvae of A. cantonensis was 40. 0% (82/205) in the snails. (4) Major clinical manifestations in the 8 patients included: severe headache(8/8), dizziness(8/8), nausea(8/8), vomiting(8/8), lethargy(7/8), lower limb hypody-namia(7/8). Conclusion The confirmation of severe infection of A. cantonensis in 8 child patients demonstrated that a natural nidus of angiostrongyliasis is present in Chengle City.

Key words: Angiostrongylus cantonensis, Pita gigas, epidemiology