Author(s): Fengyang Min; Jiasheng Wang; Shizhu Li; Xu Xingjian; Yuan Yi; Guo Yunhai; Chen Muxin
Linked Author(s):
Keywords: No keywords
Abstract: Schistosomiasis mansoni is one of the most prevalent neglected tropical diseases, affecting millions of people in developing countries. The freshwater snail Biomphalaria straminea, as an intermediate host of S. mansoni, is expanding its geographic range in Gonuangdong Province, China. It has caused potential risk of an epidemic of S. mansoni in southern China. This study explored its primary parameters of the hydraulics characteristics including density, hydrostatic setting velocity and locomotion in different water depth to evaluate its potential risk on transmission of schistosomiasis mansoni. The density and hydrostatic setting velocity of B. straminea were measured using the drainage volume and setting tube method, respectively. The behavior and distribution characteristics of B. straminea in different water depths were observed by the Plexiglas tube method. The effects of hydrostatic pressure on the climbing speed of B. straminea were also analyzed. The results show that the average density of the B. straminea is 1.08 g/cm 3. The hydrostatic setting velocity of B. straminea is between 2.32 cm/s and 12.92 cm/s in the water, there is no significant difference between the settling velocity and their shape type. In the Plexiglas tubes with different depths, we observed that the locomotion can occur in six manners. The B. straminea distributed mainly along the surface and at the bottom layer of the tubes and the proportion of the B. straminea on the surface water generally raised as time increased. Also, we noted a piecewise linear relationship between the climbing speed of the B. straminea and hydrostatic pressure in different water depth. It revealed that the climbing speed of B. straminea increases first and then decreases with the water depth increase, and reaches the maximum when the water depth at 120cm. The findings of this study indicate that there are significant differences between the density, the hydrostatic setting velocity and climbing speed of B. straminea compared with Oncomelania hupensis. Future studies should be conducted more deeply on hydraulics characteristics of B. straminea and thus establish adequate water conservancy measures to control its dispersion.
Year: 2022