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.
Objective:Foodborne parasitic diseases,although with a declining overall incidence rate,are still endangering local public safety.This review aims to describe the current situation and epidemiological trends of foodborne parasitic diseases in China in order to explore possible reasons contributors to its high prevalence in some areas,and propose strategies for prevention and control accordingly.Methods:A scoping review was conducted by searching Pub Med,CNKI,Wanfang,CQVIP,Embase,and the Cochrane Library using search formula"foodborne parasitic diseases(or foodborne parasites)"AND"China".Studies on foodborne parasitic diseases in China were considered,but only articles in English or Chinese published between January 1980 and June 2020 were retrieved.Included studies were screened according to the eligibility criteria:1)diseases consistent with the WHO definition of foodborne parasitic diseases;2)the food carriers were included in the WHO food classification;3)data related to epidemiology,pathogenicity,and prevention and control;4)Foodborne parasitic diseases cases or outbreaks in China.Results:A total of 111 out of 665 records were included and summarized.The prevalence of clonorchiasis,angiostrongyliasis,echinococcosis,trichinellosis and cysticercosis was still increasing although the infection rate of soil-transmitted nematodes has substantially decreased in recent years.Diverse eating habits,close contact with animals,and urbanization were contributing factors to the increase.Conclusions:Foodborne parasitic diseases remain an important public health issue in China with the progress of economic globalization and food diversification.We should manage to raise public awareness about the prevention and control of foodborne parasitic diseases,improve health and safety inspections,as well as public health practice.
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.
