Background:Snail-borne parasitic diseases,such as angiostrongyliasis,clonorchiasis,fascioliasis,fasciolopsiasis,opisthorchiasis,paragonimiasis and schistosomiasis,pose risks to human health and cause major socioeconomic problems in many tropical and sub-tropical countries.In this review we summarize the core roles of snails in the life cycles of the parasites they host,their clinical manifestations and disease distributions,as well as snail control methods.Main body:Snails have four roles in the life cycles of the parasites they host:as an intermediate host infected by the first-stage larvae,as the only intermediate host infected by miracidia,as the first intermediate host that ingests the parasite eggs are ingested,and as the first intermediate host penetrated by miracidia with or without the second intermediate host being an aquatic animal.Snail-borne parasitic diseases target many organs,such as the lungs,liver,biliary tract,intestines,brain and kidneys,leading to overactive immune responses,cancers,organ failure,infertility and even death.Developing countries in Africa,Asia and Latin America have the highest incidences of these diseases,while some endemic parasites have developed into worldwide epidemics through the global spread of snails.Physical,chemical and biological methods have been introduced to control the host snail populations to prevent disease.Conclusions:In this review,we summarize the roles of snails in the life cycles of the parasites they host,the worldwide distribution of parasite-transmitting snails,the epidemiology and pathogenesis of snail-transmitted parasitic diseases,and the existing snail control measures,which will contribute to further understanding the snail-parasite relationship and new strategies for controlling snail-borne parasitic diseases.
Background:The invasive alien species may lead to great environmental and economic crisis due to its strong capability of occupying the biological niche of native species and altering the ecosystem of the invaded area.However,its potential to serve as the vectors of some specific zoonotic pathogens,especially parasites,has been neglected.Thus,the damage that it may cause has been hugely underestimated in this aspect,which is actually an important public health problem.This paper aims to discuss the current status of zoonotic parasites carried by invasive alien species in China.Main body:This review summarizes the reported zoonotic parasites carried by invasive alien species in China based on the Database of Invasive Alien Species in China.We summarize their prevalence,threat to human health,related reported cases,and the roles of invasive alien species in the life cycle of these parasites,and the invasion history of some invasive alien species.Furthermore,we sum up the current state of prevention and control of invasive alien species in China,and discuss about the urgency and several feasible strategies for the prevention and control of these zoonoses under the background of booming international communications and inevitable globalization.Conclusions:Information of the zoonotic parasites carried by invasive alien species neither in China or worldwide,especially related case reports,is limited due to a long-time neglection and lack of monitoring.The underestimation of their damage requires more attention to the monitoring and control and compulsory measures should be taken to control the invasive alien species carrying zoonotic parasites.
Schistosomiasis is an important zoonotic parasitic disease that causes serious harms to humans and animals.Surveillance and diagnosis play key roles in schistosomiasis control,however,current techniques for surveillance and diagnosis of the disease have limitations.As genome data for parasites are increasing,novel techniques for detection incorporating nucleotide sequences are receiving widespread attention.These sensitive,specific,and rapid detection methods are particularly important in the diagnosis of low-grade and early infections,and may prove to have clinical significance.This paper reviews the progress of nucleic acid detection in the diagnosis and prevention of schistosomiasis,including such aspects as the selection of target genes,and development and application of nucleic acid detection methods.
