Purdue University, West Lafayette, Indiana, United States of America.
PLoS Negl Trop Dis. 2022 Feb 24;16(2):e0009524. doi: 10.1371/journal.pntd.0009524. eCollection 2022 Feb.
Seawater intrusion associated with decreasing groundwater levels and rising seawater levels may affect freshwater species and their parasites. While brackish water certainly impacts freshwater systems globally, its impact on disease transmission is largely unknown. This study examined the effect of artificial seawater on host-parasite interactions using a freshwater snail host, Biomphalaria alexandrina, and the human trematode parasite Schistosoma mansoni. To evaluate the impact of increasing salinity on disease transmission four variables were analyzed: snail survival, snail reproduction, infection prevalence, and the survival of the parasite infective stage (cercariae). We found a decrease in snail survival, snail egg mass production, and snail infection prevalence as salinity increases. However, cercarial survival peaked at an intermediate salinity value. Our results suggest that seawater intrusion into freshwaters has the potential to decrease schistosome transmission to humans.
海水入侵与地下水水位下降和海平面上升有关，可能会影响淡水物种及其寄生虫。虽然咸水肯定会影响全球的淡水系统，但它对疾病传播的影响在很大程度上尚不清楚。本研究使用淡水蜗牛宿主 B. alexandrina 和人类吸虫寄生虫曼氏血吸虫，研究了人工海水对宿主-寄生虫相互作用的影响。为了评估盐度增加对疾病传播的影响，分析了四个变量：蜗牛存活率、蜗牛繁殖、感染率以及寄生虫感染阶段（尾蚴）的存活率。我们发现，随着盐度的增加，蜗牛存活率、蜗牛卵质量产量和蜗牛感染率均下降。然而，尾蚴的存活率在中间盐度值达到峰值。我们的结果表明，海水入侵淡水可能会降低人类感染血吸虫的风险。
