Analysis of a survey on the infection of Achatina fulica with Angiostrongylus cantonensis in Guangzhou, Guangdong province.

The infection of the Ⅲ stage worms of Anchatina fulica with Angiostrongylus cantonensis was investigated and compared with the infection in other areas of China to add the additional epidemiological data of this parasite in Guangzhou,Samples of A.fulica were collected from various districts in Guangzhou area in July 2000 and July 2004,and the infection rate and intensity with A.cantonensis were compared with the data obtained from other cities of China.Meanwhile,the rat and mouse models of infection were established by stomach intubation and the morphological characteristics of the late stage worms in brain,heart and lungs of the infected animals were examined.It was found that the infection rate discovered in 5 districts of Guangzhou in 2000 was 44.2%(57/129),and the infection intensity was 401 worms per A.fulica.,while in 2004,the former was 27.3%(33/121) and the latter was 72 worms per A.fikca.Significant differences in infection rates of these two courses of infection existed(χ~(2)=7.5,P0.01).Both the infection rate and infection intensity in Guangzhou area were rather lower than those in other cities with breakout ever before,such as Wenzhou,Zhejiang province and Changle,Fujian province,but higher than those of other places where there was no any breakout before,such as Fuzhou,Fujian province.The infection rates from different districts in Guangzhou were also different and the highest rate of infection of 65.9% occurred in Lijiao village.In addition,the positive rate of infection positively correlated with the weight of snails,and both rat and mouse models could be infected with worms.It is evident from the above observations that the infection rate and intensity of A.fulica with A.cantonensis show a tendency to decline,in which the infection rate of 2004 in Guangzhow appears to be lower than those of other epidemic cities in China.It is also clear that mouse is suitable to establish the animal model of infection with IV and V stages A.cantonensis,and rat is fit for adult worms.