Abstract:

Objective  To investigate the infection status of Potamon denticulate, the second intermediate host of Paragonimus in Huangshan area in order to provide scientific basis for prevention and control of paragonimiasis. Methods  The survey sites were initially anchored according to the distribution nature of local water system and previous findings as well as local environment. Appropriate streams were selected, and the crabs were manually captured or harvested with a cage. The metacercariae of lung fluke were isolated in the lab under anatomical lens, and the infection rate of crabs and the infection index of metacercaria were calculated. Results  A total of 275 crabs were obtained in 12 administrative villages of 11 towns, and 57 were found infested with the Paragonimus(positive rate: 20.73%). The infectiosity was 3.51/per crab, and the metacercaria was counted as 0.958 in pergram of the infected crab. The infection index of metacercaria was 0.194 06. The prevalence and infectiosity were positively correlated with the weight of crab (r= 0.905, P<0.02; r= 0.929, P<0.01). The positive incidence and the infectiosity were higher in male crabs than in the female ones(χ2=136.53, P＜0.01), and the difference was significant for the positive incidence of crabs living in dissimilar rivers(χ2=7.70, P＜0.05). Conclusion  Our findings suggest that paragonimiasis is still endemic risks in Huangshan area, and Xin'an river basin shall be the focus of following paragonimiasis control.

Key words: Paragonimus, Second intermediate host, Potamon denticulate, Prevalence survey, Huangshan city