Oncomelania snail is the only intermediate host of Schistosoma japonicum, and controlling snail breeding and spread is an important intervention for schistosomiasis control. This review summarizes factors affecting snail spread, characteristics of snail spread in various endemic areas, high-risk environments of snail spread and monitoring methods of snail spread, so as to provide insights into the prevention of snail spread.Recently, the incidence of infectious diseases continues to decline in many developed countries; however, the incidence of autoimmune diseases and allergic asthma appears a tendency towards a rise over years. "Hygiene hypothesis" provides new insights into the treatment of autoimmune disorders and allergic diseases based on parasitic infections. Increasing evidence shows that parasitic infections may effectively inhibit the development of diabetes, multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis and allergic asthma. There are complex mechanisms underlying the relationship between parasitic infections and "hygiene hypothesis", among which regulatory T (Treg) cells and Th17 cells are becoming a hot topic of research. This paper reviews the progresses in the research on the relationship between parasitic infections and "hygiene hypothesis", and summarizes the roles of Treg cells and Th17 cells in the interplay between parasitic infections and "hygiene hypothesis".Objective To build a discriminant function of clonorchiasis sinensis using stepwise discriminant analysis, so as to investigate the feasibility of discriminant analysis for clonorchiasis sinensis screening. Methods Ten villages in Mulan County of Harbin City were sampled as the study sites using a cluster random sampling method. The fecal samples were collected from the permanent residents in the study sites and detected for Clonorchis sinensis eggs using the modified Kato-Katz smear technique. A questionnaire of clonorchiasis sinensis was designed. All data were entered into Epidata 3.1, and a discriminant analysis was performed using the software SPSS version 15.0. Variable were screened using the stepwise discriminant analysis, and the discriminant function was built using the Fisher's discriminant analysis method. The effectiveness of the discriminant function for clonorchiasis sinensis screening was evaluated by comparison with the modified Kato-Katz smear method. Results Eight variables with statistical significance were included to build the discriminant function, including chronic cholecystitis, cholangitis, gender, eating raw fish, abdominal distension, ethnicity, abdominal pain and age, and the correction rate of the discriminant function was 88.75% to identify clonorchiasis sinensis. Conclusions The discriminant function of clonorchiasis sinensis can be rapidly and simply built based on the strong data processing and analysis capability of the SPSS software, which is rapid to screen clonorchiasis sinensis in Harbin City. Such a function has a high discriminant analysis capability, and provides insights into the establishment of rapid screening of clonorchiasis sinensis in other endemic areas.Objective To investigate the survival period of Yunnan Province-derived smooth-shelled Oncomelania snails bred in laboratory. Methods Oncomelania snails were sampled from Heqing and Yongsheng counties where schistosomiasis is endemic, and uninfected adult snails were collected and bred in laboratory. The survival period of snails sampled from these two counties was compared. Results The 1-, 2-, 3- and 4-year survival rates of laboratory-bred smooth-shelled snails sampled from Yunnan Province were 72.36%, 29.11%, 13.08% and 0.21%, respectively, and were 74.66%, 38.91%, 19.46% and 0.45% for snails derived from Heqing County, and 70.36%, 20.55%, 7.51% and 0 for snails sampled from Yongsheng County, respectively. The mean and median survival period of Yunnan Province-derived adult snails was 20.90 and 20.67 months, and there were significant differences between the snails sampled from Heqing and Yongsheng counties in terms of the mean (22.94 vs. 19.13 months, P less then 0.05) and median survival period (21.63 vs. 19.81 months, P less then 0.05). Conclusions The mean survival period of Yunnan Province-derived smooth-shelled adult snails is approximately 20 months in laboratory, and the survival varies in geographical areas.Objective To observe the morphological changes in the testes and ovaries of adult 12th-generation Oncomelania hupensis bred for 12 winters in Weishan Lake areas. Methods The offspring of the adult O. hupensis snails bred in the Weishan Lake that were originated from the Yangzhou section of the Yangtze River was defined as the experiment group, while uninfected, adult O.  https://www.selleckchem.com/products/resatorvid.html  hupensis snails captured from the marshland of the Yangzhou section of the Yangtze River served as the control group. Snails were dissected and intact testicular and ovarian specimens were sampled, routinely fixed, dehydrated, embedded, polymerized in an oven and sliced on an ultramicrotome. The sections were visualized under a transmission electron microscope, and the ultrastructure of the snail gonad was compared between the experiment and control groups. Results Transmission electron microscopy showed "9 + 2" microtubules on the transverse sections of the tails of sperm cells in the testes of male snails in the control group, with triangulaas.Objective To investigate the morphological characteristics of Echinostoma miyagawai in domestic ducks in Wuhu area, and to explore the feasibility of the cytochrome oxidase subunit-1 (Cox1) gene as a molecular marker for the identification of E. miyagawai. Methods E. miyagawai was isolated from free-ranged domestic ducks in Wuhu area, and the parasites were stained and identified. In addition, the mitochondrial Cox1 gene of E. miyagawai was amplified using a PCR assay, and the amplification product was sequenced and aligned with the GenBank database to yield the homology for the identification of parasite species in combination with morphological findings. Intra-species comparison was done based on the Cox1 gene sequence. Results The prevalence of E. miyagawai infection was 16.67% in domestic ducks in Wuhu area, and the adult E. miyagawai was 6.6 to 13.2 mm in length. The size of the E. miyagawai Cox1 gene was approximately 660 bp, which had a 99.68% homology to the E. miyagawai accessed in GenBank. The morphological findings were in agreement with molecular identification.