RESUMO
<p><b>OBJECTIVE</b>To analyze the degrees on the epidemic foci of Angiostronglus cantonensis and to explore the measurement methods.</p><p><b>METHODS</b>Snails (Pila gigas) were collected from the spots of Wenzhou, Cangnan, Yongjia, Yueqing in Zhejiang province and Minhou, Changle, Ningde in Fujian province. The snails were examined microscopically in order to calculate their infection rates and the average worm number in the positive snails, then taking the product of multiplication of both values as infestation index.</p><p><b>RESULTS</b>The infection rates of the epidemic foci were 10.59% (9/85), 60.74% (181/298), 34.96% (79/226), 32.90% (76/231), 57.50% (184/320), 40.00% (82/205), 17.65% (12/68) and the rates of infectivity were 6.57, 183.54, 121.73, 93.45, 276.36, 76.08, 12.65, respectively.</p><p><b>CONCLUSION</b>The epidemic foci were divided into five ranks (super, high, mid-range, low and non-epidemic foci) according to the value of infestation index which ranked from > 75, 30-75, 5-29, < 5 to 0.</p>