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Both parasitic diseases and cancers are disorders that seriously threaten human health. A strong correlation has been recently found between parasitic infections and cancers, and multiple species of parasites and their derived products have shown effective to suppress cancer development, progression and metastasis. Therefore, deciphering the interaction among parasites, cancers and hosts not only provides new insights into the development of cancer therapy, but also provides the basis for screening of parasites-derived active anticancer molecules. This review summarizes the latest advances in the anticancer activity of parasites and underlying mechanisms.

Helminth infections are widespread worldwide, and pose a serious threat to human health and animal husbandry development. Understanding of helminth-host interactions is critical to effective control and ultimate eradication of helminthiasis. Following host infections, helminth infections firstly initiate innate immune responses and then mediate adaptive immune responses. Type 1 immune responses are predominant at early stage of helminth infections, which mainly play anti-infective actions, and type 2 immune responses are predominant at late stage of infections, which are associated with helminth immune evasion and aggravation of tissue damages. This review summarizes the progress of researches on type 1/2 immune responses-associated signaling pathways mediated by helminth infections in hosts.

Autophagy, a conserved intracellular degradation system, is a specific life phenomenon in eukaryocytes. Autophagy is widely accepted as a pathway that double-membrane autophagosomes envelop and sequester intracellular cytoplasmic components and then fuse with lysosomes to form autolysosomes, which degrade their contents to regenerate nutrients. Autophagy may be triggered by starvation and a diverse range of pathogens, including parasites. Following infection with intracellular parasites, host cells may eliminate parasites by autophagy. However, parasites may develop self-defense mechanisms, and promote the self-growth and -development by host cell autophagy. This review describes the advances in the interplay between parasitic infections and host cell autophagy. Understanding autophagy is of great significance for the management of parasitic infections and the development of antiparasitic drugs.

Objective: To predict the colonization risk and potential geographical distribution of Biomphalaria glabrata in the Mainland China based on the past period temperature data., Methods: The survival extreme high temperatures and low temperatures of B. glabrata eggs, young and adult B. glabrata snails and the average effective accumulated temperature of generation development were determined in laboratory conditions. The temperature data in January and July from 1955 to 2010 were collected from the national meteorological monitoring sites in the southern part of China, including Chongqing, Zhejiang, Yunnan, Sichuan, Jiangxi, Hunan, Hainan, Guizhou, Guangdong, Guangxi and Fujian provinces (11 provinces). A database of ambient temperature related to B. glabrata was established based on the Geographic Information System (GIS). The colonization risk and potential geographical distribution of B. glabrata in the southern part of China were analyzed and predicted by ArcGIS 10.1 software., Results: The half lethal low temperatures of B. glabrata eggs, young and adult B. glabrata snails were 6.80, 6.34 ℃ and 6.60 ℃ respectively; the half lethal high temperatures of B. glabrata eggs, young and adult B. glabrata snails were 35.99, 33.59 ℃ and 32.20 ℃, respectively. The developmental threshold temperature was 7.16 ℃; the average effective accumulated temperature of generation development was (1 970.07 ± 455.10) days-degree. The GIS overlay analysis of the half lethal low and high temperatures of B. glabrata showed that the local temperature conditions in all Hainan and part regions in Yunnan, Guangxi, Guangdong and Fujian were conformed to the survival temperature of B. glabrata snails. The regions, where the average effective accumulated temperature was more than the average effective accumulated temperature of generation development of B. glabrata , were Guangdong and Hainan, and part regions of other 9 provinces. The overlay analysis of GIS maps of the survival extreme high temperatures and low temperatures of B. glabrata with the GIS map of the average effective accumulated temperature of generation development in 2010 showed that the whole region of Hainan and part regions of Guangdong, Guangxi, Yunnan and Fujian were potential geographical distribution regions of colonization risk of B. glabrata . The overlay analysis of GIS maps of the survival extreme high temperatures and low temperatures of B. glabrata with the GIS map of the average effective accumulated temperature of generation development from 1955 to 2010 showed that the potential geographical distribution regions of B. glabrata was expanding from the whole region of Hainan and part regions of Guangdong in 1955 to the whole region of Hainan and part regions of Guangdong, Guangxi, Yunnan and Fujian in 2010., Conclusions: If B. glabrata snails were introduced into the Mainland China, the potential geographical distribution regions would be the whole region of Hainan and part regions of Guangdong, Guangxi and Yunnan. The changes of risk range and risk intensity present the trends of expanding and increasing from the south to the north gradually.

Objective: To investigate the mechanism of Toll-like receptor in intestinal mucosal injury induced by Cryptosporidium parvum infection in mice., Methods: Totally 30 male BALB/c mice were randomly divided into a normal control group, 1week infection group and 2-week infection group. The mice of the 1-week and 2-week infection groups were sacrificed 7 days and 14 days after the infection respectively, and the mice of the normal control group were sacrificed 14 days after the infection. The model of intestinal infection of C. parvum in mice was built by using the immunosuppressive method and oocyst intragastric administration. The pathological changes of the intestinal mucosa of mice were observed with a light microscope and the villus height, crypt depth and ratio of villus height/crypt depth were measured. The ultrastructure of the intestinal mucosa of mice was observed by a transmission electron microscope (TEM). The expressions of TLR2 and TLR4 in the intestinal mucosa were tested by qPCR and Western blotting., Results: Under the light microscope, the intestinal villi were dropsical, obviously atrophied and shortened, and the submucosal structure was dropsical. The height of chorionic villi and the ratio of villus height to crypt depth in the jejunum of the 1-week and 2-week infection groups were significantly lower than those in the normal control group (all P < 0.05), while the depth of the recess of the former two was significantly increased (all P < 0.05). With the extension of the infection time, the villus height and the ratio of villus height to crypt depth in the jejunum of mice decreased significantly (both P < 0.05), and the crypt depth increased significantly ( P < 0.01). The TEM observation showed that the structure of the oocyst of C. parvum in the jejunum of the infected mouse was intact, the villi around the oocyst were abscission seriously, and the oocyst wall was fused with the epithelial cell membrane. The qPCR observation showed that compared with the normal control group, the expressions of TLR2 mRNA and TLR4 mRNA in the intestinal mucosa of the 1-week and 2-week infection groups were significantly higher (all P < 0.05). In addition, the expressions of TLR2 and TLR4 mRNA in the 2-week infection group were significantly higher than those in the 1-week infection group (both P < 0.05). The Western blotting showed that the expressions of TLR2 protein and TLR4 protein in the intestinal mucosa of the 1-week and 2-week infection groups were significantly higher than those of the normal control group (all P < 0.05). Furthermore, the expressions of TLR2 and TLR4 protein in the 2week infection group were significantly higher than those in the 1-week infection group (both P < 0.05)., Conclusions: TLR2 and TLR4 are important receptors for intestinal mucosal recognition of C. parvum . The C. parvum infection may lead to intestinal mucosal damage possibly via the mechanisms associated with the up-regulation of TLR2 and TLR4 expressions.

With the rapid development of molecular biological techniques, DNA microarray has shown great advantage in biology and medicine as it allows high-throughput measurement of various biological parameters. Trypanosomiasis remains the focus among numerous human blood parasitic diseases. The DNA microarray is a useful technique for studying the trypanosome genome and parasite-host interaction, as well as for vaccine screening and drug development. This review gives an update on the application of DNA microarray in human research on Trypanosoma brucei and Trypanosoma cruzi.

Objective: To understand the endemic dynamic and situation of schistosomiasis in the Xixi National Wetland Park., Methods: The surveillances of Oncomelania hupensis snail situation and the schistosome infection status of the permanent residents and floating population in the Xixi National Wetland were conducted annually from 2012 to 2014 according to the Surveillance Programs of Schistosomiasis in Surveillance Sites of Zhejiang Province., Results: From 2012 to 2014, accumulatively 12.31 hm2 of area, 4965 m2 of vegetation and 75,379 alien plants were surveyed in the Xixi National Wetland Park, and no Oncomelania snails were found. The seropositive rates in the permanent residents and floating population were 0.71% (5/706) and 1.36% (25/1 834), respectively, and 1 imported chronic schistosomiasis case was found in 2014. Totally 3 006 floating personnel were involved in the investigation of infection status and awareness on knowledge of schistosomiasis control in 2013, the sero-positive rate was 0.63% (19/3 006), and the rates of those from endemic and non-endemic areas were 1.00% (15/1 503) and 0.27% (4/1 503), respectively, and the difference was statistically significant ( χ2 = 6.41, P < 0.05). The results of the fecal examinations among the seropositive cases were all negative. The awareness rates on the Regulation of Schistosomiasis Control and Prevention as well as related knowledge about Oncomelania snails were low. The indoor survival experiment of Oncomelania snails showed the survival rates of Oncomelania snails were 58.33% and 1.25% after observing for 3 and 6 months respectively., Conclusions: The Xixi National Wetland Park is suitable for Oncomelania snails to inhabit and breed. The imported cases in floating population pose a serious threat to the endemic situation of schistosomiasis in local. In the future, the surveillance on snails and floating population as well as the health education should be strengthened.

This paper reports a case of upper gastrointestinal bleeding induced by hookworm infection, which was misdiagnosed at the beginning, and analyzes the causes of misdiagnosis.

Objective: To evaluate the effectiveness of mid- and long-term schistosomiasis control plan and explore the consolidation strategy in marshland endemic regions, so as to provide an effective approach for interrupting and eliminating schistosomiasis in the regions., Methods: A prospective field study was designed. Dantu District of Zhenjiang City, a marshland schistosomiasis endemic region, was selected, and the "key village, key environment, and key water regions" comprehensive control strategy was implemented according to the endemic level of schistosomiasis. The morbidity due to schistosomiasis in humans and domestic animals, and Oncomelania hupensis snails were surveyed, and the data of the implementation of control measures were collected. The schistosomiasis morbidity and snail status were compared before and after the implementation of the mid- and long-term plan for schistosomiasis prevention and control, and the changing trends of human, domestic animal and snail infections were plotted., Results: During the implementation of the plan from 2005 to 2014, 16.84 km concrete and bank protection and 9 snail sinks were built, 10 culverts re-built, 3.85 hm2 fences were constructed, 29.5 thousand domestic animals were examined and treated, 170 cattle were eliminated, 4930 hm2 fishing farms were built for snail control, 1 560.00 hM2 land were improved, and 376.00 hm2 forests were built for snail control. In addition, 19,364.80 hm2 snail areas were surveyed, 4694.6 hm2 area received molluscicide, 207.9 thousand of people (person-times) received the examination and treatment, 69.1 thousand of harmless toilets were built, 282.2 thousand health education materials and protection materials were allocated, 958 warning signs were established, and 5435 slogans were pasted or hung. After the implementation of the mid- and long-term plan, the percentages of human, bovine and snail infections appeared decline tendencies year by year, and reduced from 0.08%, 1.28% and 0.13% in 2005 to 0 in 2014, respectively, while the areas with snails and infected snails reduced from 284.34 hm2 and 55.10 hm2 in 2005 to 73.60 hm2 and 0 hm2 in 2014, with reduction rates of 74.12% and 100%, respectively. The infection rate of sheep appeared a fluctuation between 2005 and 2014, with the rate of 1.13% in 2005, 0 in 2007 and 2008, rising in 2009 and then between 0.25% and 0.95% from 2009 to 2012, and reducing to 0 in 2013 and 2014. During the 10-year period, the number of cattle reduced year by year from 2005 to 2010, and slightly increased after 2011, showing an overall stable level, while the number of sheep increased year by year after 2006, peaked in 2010, and appeared a decline tendency since 2011, which was almost consistent with the fluctuation of schistosome infection rate in sheep., Conclusions: The sustainable comprehensive control strategy with the "key village, key environments, and key water regions" is an effective approach for schistosomiasis control in marshland endemic regions. However, the endemic situation of schistosomiasis is extremely easy to repeat. The prevention and control of the impact of sheep and wild animals on schistosomiasis transmission should be strengthened in order to consolidate the schistosomiasis control achievements gained.

Objective: To master the dynamic endemic status and influencing factors of schistosomiasis in Yunnan Province, so as to provide the evidence for making the control and prevention measures., Methods: Four villages of four schistosomiasis heavy endemic counties were selected as survey sites. Then, the serological screening and etiological tests were carried out in the residents, and the basic situations of the survey sites were investigated. The infection status of the livestock and relevant information of Oncomelania hupensis snails were surveyed. All the results were analyzed statistically., Results: Totally 4310 residents were surveyed by the indirect hemagglutination assay with the examination rate of 79.68% and serum positive rate of 8.40%. The positive rate reached upwards 12.53% in Qiandian Village of Eryuan County. The serum positive rate of the female was higher than that of the male, and the positive rates of the 30 years and older age groups were higher than those of the other age groups. The serum positive rates of the peasants, migrant labourers and residents with the junior high school education level were higher. No positive feces were found. A total of 24 advanced cases were reported. No positive livestock and snails were found, and the average density of living snails was 0.023 3-0.056 6/0.1 m2., Conclusion: Right now, the schistosomiasis is at a low prevalence status in Yunnan Province, and the endemic situation has been effectively controlled.

To separate and identify chemical signals which induce Thesium chinense haustorium formation, the components of T. chinense roots secretion collected with XAD-4 resin were detected by GC-MS. The effect of DMBQ as exogenous signals to induce haustorium formation in T. chinense was studied. Fifty-three compounds of 9 types had been detected, including hydrocarbons, esters, organic acids, ketones, alcohols, nitrogen containing compounds, phenolic acids, aldehyde and quinine. It is worth noting that the 2, 5-di-tert-butyl-1,4-benzoquinone has the core structure of 1,4-benzoquinone, which may play an important role in the parasitic relationship of Prunella vulgaris and T. chinense: DMBQ worked effectively on inducing haustoria, but induction effects vary widely in different concentrations. DMBQ with the concentration of 1 μmol x L(-1) showed the best effect of the inducing ability with a ratio of 110.52 when treated to induce haustoria.

Rhoptry proteins are the major virulence factors of Toxoplasma gondii. They locate in different parts of the host cells, and can affect the membrane, cytoskeleton structure and active factors of the host cells, so as to block the cell intrinsic defense mechanisms of the host, and let T. gondii invade, parasitize and proliferate in the host successfully. The function and ac- tion mode of rhoptry proteins reflect the pathogenic mechanism of T. gondii, which holds great significance to looking for toxoplasmosis drug targets and developing molecule vaccines. This paper reviews the research progess of the interaction between rhoptry proteins of T. gondii and host cells.

The larval and adult schistosomes can effectively establish the stable parasitic relationship with their final hosts and then maintain the parasitism for a long time, due to the successful adaptation to their parasitic lifestyle. This paper reviews the progress of research on parasitic adaptability of schistosomes in several respects, and demonstrates the application value of schistosomal genes related to parasitic adaptability in schistosomiasis control and exploitation of natural active molecules.

Grooming behavior is evolved in animals in response to the costs associated with ectoparasites. In this study, ecotparasite densities and grooming behavior-including licking and scratching-of wild-caught lesser bamboo bat (Tylonycteris pachypus) and greater bamboo bat (T. robustula) were analyzed. The results indicated that both the frequencies and durations of licking were higher than those of scratching in both bat species, though T. pachypus licked more but scratched less than T. robustula. There were no difference in the durations of licking and scratching between the two bat species, and the durations and frequencies of grooming behavior of the two bat species were irrelevant with ectoparasite densities. These findings suggest that the grooming behavior of T. pachypus and T. robustula might be modulated by both the central control (programmed grooming) model and the peripheral stimulation (stimulus driven) model.

Objective: To investigate the prevalence of Capillaria hepatica in rodents from Anning Prefecture, Yunnan, and observe the susceptibility of C. hepatica to SD rats and KM mice., Methods: Rodents were trapped in a cultivated filed of Wenquan Town, Annning from March 2010 to March 2012. The species of rodents were identified. The liver was examined and a microscopic examination of tissue was performed by the tissue press technique for the presence of the typical bipolar eggs, adults or larval stages. The prevalence of C. hepatica in rodents was calculated. C. hepatica eggs were collected and cultured in vitro. Each SD rat or KM mouse was orally infected with approximately 1 000 C. hepatica eggs. The control groups with 4 SD rats or 4 KM mice received only normal saline. The experimental animals were euthanized at the 30th and 80th day post infection. Collected liver samples were processed for gross pathological and histological section examination., Results: A total of 115 rodents were captured and examined. C. hepatica eggs were found in 26 (22.6%) rodents. There was no significant difference in the prevalence between female (22.5%, 18/80) and males (22.9%, 26/115) (P > 0.05). The highest prevalence was found in Rattus norvegicus (10/11). Pathologi cal findings showed numerous white-yellow small nodules ranged from 0.1-0.2 cm in diameter. Under light microscope, C. hepatica eggs were ovoid [(50-65) microm x (25-30) microm]. At the 30th day post-infection, there were several adult worms and their eggs delimited by a fibrous capsule, and septal fibrosis formations occurred in the liver of SD rat. No worm or eggs were found in the mouse liver, but the liver presented inflammatory cell infiltration. At the 80th day post-infection, live worms disappeared from the focal lesions in the liver of SD rat, being replaced by partially calcified worm debris. Mature worms and eggs were seen in the KM mouse liver, however, septal fibrosis was absent., Conclusion: This study has documented a high prevalence of C. hepaticum in R. norvegicus from Anning Prefecture. SD rat and KM mouse are the susceptible hosts of C. hepatica.

Objective: To investigate the species composition and distribution of chigger mites on small mammals in flatland area in Menghan, Xishuangbanna of Yunnan Province., Methods: The field investigation was made in a flatland area near Lancangjiang River in Menghan, Xishuangbanna of Yunnan Province. Small mammals were captured with mouse cages and traps. All mites on the hosts were collected and preserved in 70% ethanol. Hoyer's solution was used to mount the chiggers on glass slides. The specimens of the chigger mites on the slides were finally identified into species under microscope. The constituent ratio, infestation rate, mean abundance and mean intensity of chigger mites in different habitats or on different hosts were used to measure the community structure. The species richness and community diversity were analyzed., Results: A total of 233 small mammal hosts were captured (belonging to 2 families, 3 genera and 5 species). 5 763 individuals of chigger mites were identified as 2 subfamilies, 7 genera, and 45 species. Rattus tanezumi (R. flavipectus) was the dominant species among the captured hosts, accounting for 97.4% (227/233). The mite infestation rate, average ectoparasite abundance, and mean mite intensity on R. tanezumi was 56.4% (128/227), 24.7 (5 600/227) and 43.8 (5 600/128), respectively. Leptotrombidium deliense was dominant chigger mite species and account for 57.9% (3 337/5 763), mainly infested R. tanezumi. Compared with indoor and cultivated field habitats, the species richness and community diversity of chigger mites in shrub habitat were higher, and 41 species of chigger mites were collected., Conclusion: The species composition and community structure is relatively simple in the flatland area in Xishuangbanna. L. deliense is the most dominant species of chigger mites and its main host is R. tanezumi.

A comparative study was conducted on the life table parameters of Aphis gossypii reared on five host plant species at (25 +/- 1) degrees C in laboratory. There existed significant differences in the durations of various developmental stages, adult longevity, mean offspring number per day, net reproductive rate, intrinsic rate of increase, finite rate of increase, mean generation time, and population doubling time for the A. gossypii populations reared on the host plants. For the aphids on Lagenaria siceraria var. turbinate, they needed the longest time (5.84 days) to complete one generation, but for those on the other four plants, no significant differences were observed, with the time needed ranged from 5.24 to 5.45 days. The adult longevity was the longest (20.04 days) on Cucumis sativus, but had no significant differences on the other four host plants, being from 14.76 to 16.03 days. The populations' survival curves on all test host plants were of Deevey I, i. e., the death mainly occurred during late period. The survival rate on C. sativus was higher than those on the other four host plants. Based on the intrinsic rates of increase of A. gossypii, its host suitability was in the order of Cucumis melo var. saccharinus > Lagenaria siceraria var. turbinate > Cucurbita moschata var. melonaeformis > Cucumis sativus > Cucurbita pepo var. medullosa.

The specificity of schistosomes to hosts and the compatibility of hosts to schistosomes are formed during the long evolution process of them, they are not only related closely to environment but also to other factors such as the heredity of schistosomes and hosts. This paper reviews the non-adaptivity of schistosomes and hosts from the respects of genetics, immunology, cytobiology, molecular biology, and physiology.

It is an important way to massively rear parasitoid wasps by using appropriate methods to treat the wasps' hosts and preserve them for a long duration. Pachycrepoideus vindemmiae Rondani is a pupal parasitoid of several dipteral pests, being of significance for the biological control of the pests. In this paper, housefly pupae were frozen at -20 degrees C, cold storage-preserved at 6 degrees C, and CO2-asphyxiated for 1-, 3-, and 30 days, respectively, and some pupae were heat-killed and cold storage-preserved for 30 days, aimed to approach the effects of these treatment methods on the reproduction of P. vindemmiae on the pupae. The results showed that P. vindemmiae could reproduce on the pupae treated with the above-mentioned methods, and the tibia length of the offspring had less difference with that on the fresh pupae. However, the reproduction of P. vindemmiae on the pupae treated with the above-mentioned methods except frozen decreased with the increasing preserving duration of the pupae. At the prerequisite of preserving for 30 days, frozen pupae had the highest P. vindemmiae offspring reproduction, suggesting that P. vindemmiae could be massively reared when the housefly pupae were treated by frozen and cold storage-preserved.

This paper reviews the researches related to the reservoir hosts of Schistosoma japonicum, including bovine, sheep, dog, cat and wild mouse. Combined with the implementation of the comprehensive control strategy with an emphasis on infection source control in current, it puts forward several future research directions under the condition that the effects of people and bovine as infection sources weakened gradually, such as revaluation on the actual transmission capacity of non-bovine livestock, for example, sheep, dog, pig and wild mouse, as well as discussion on some transmission threshold values in the infection link of Oncomelania snails.

Oncomelania hupensis is the only intermediate host of Schistosomajaponicum, and its ecological characteristics and compatibility with Schistosoma which have a great significance to the schistosomiasis control, play a very important role in the transmission of schistosomiasis. This paper reviews the researches on the ecological factors which effect the survive of Oncomelania snails such as temperature, humidity, vegetation, and soil, as well as the snail density, the development and breeding of snails in the foreign habitats, and its compatibility with Schistosoma.

Mitogen-activated protein kinase (MAPK) is an important signaling transduction molecules, which can enter the nucleus and activate target gene when it was stimulated and become phosphorylation. MAPK signaling pathway is closely associated with various diseases. Recent studies have indicated that MAPK signaling transduction pathway is also involved in the growth and development of Echinococcus. This review summarizes the progress on the relationship between MAPK signal pathway and Echinococcus.

Objective: To screen the host cell proteins that can interact with Toxoplasma gondii ROP18 by using yeast two-hybrid system., Methods: The ROP18 gene fragments were amplified by RT-PCR from mRNA of T. gondii RH strain. The product of RT-PCR was digested with double restriction enzyme and was subcloned into the bait vector pGBKT7. The recombinant plasmid was transferred into yeast AH109 strain. Its toxicity and the autonomous activating activity were tested. The human fetal brain cDNA library was screened with pGBKT7-ROP18(25-251aa) as the bait plasmid by yeast two-hybrid system., Results: The bait was constructed and AH109/PGBKT7-ROP18 showed an autonomous activity. The yeast strain AH109/pGBKT7-ROP18(25-251aa) line was then mated with the Mate & PlateTM Human Fetal Brain cDNA library. Using the selection procedures, eight novel host cell proteins were obtained: damage-specific DNA binding protein 1 (DDB1), torsin A interacting protein 1 (TOR1AIP1), integrin beta 1, solute carrier family 3 (SLC3A2), tyrosyl protein sulfotransferase (TPST2), OCIA domain containing 1 (OCIAD1), Derl-like domain family member 2 (DERL2), in addition to Homo sapiens activating transcription factor 6 beta(ATF6)., Conclusion: Eight novel host cell proteins have been obtained via yeast two-hybrid system, which can interact with TgROP18.

As the only intermediate host of Schistosoma japonicum, the control of Oncomelania snails serves as a major part in schistosomiasis control. This review mainly demonstrates the following aspects: the invasion of schistosome miracidium into snails, the mechanism of resistance to miracidia, and the factors influencing this process. With a view to explore the methods of interrupting every phase during miracidium infection, this article focuses on the possibility for safeguarding human health through protecting snails, namely, achieving snails harmlessness.

In order to reveal the effects of temperature on the growth and development of Aglossa dimidiata parasitized on Litsea coreana, a laboratory experiment was conducted to study the mean development duration, development rate, and survival rate of A. dimidiata at its different growth stages at 31 degrees C, 28 degrees C, 25 degrees C, 22 degrees C, and 19 degrees C, with the development threshold temperature and effective accumulated temperature for different growth stages calculated. Temperature had significant effects on the developmental duration. Except that the development duration of egg was shortened with increasing temperature, the development durations of larva, pupa, and immature A. dimidiata were the shortest at 25 degrees C, being 249.53 +/- 23.83, 12.94 +/- 1.27, and 273.00 +/- 24.19 days, respectively. There existed significant relationships between the development rates of A. dimidiata at its different growth stages and temperature, with positive linear relationship at egg stage, and quadratic relationship at larva, pupa, and immature stages. Temperature also had significant effects on the survival rate of A. dimidiata. The survival rates of A. dimidiata at its different growth stages were all the highest at 25 degrees C, being 94.0%, 73.8%, 91.3%, and 63.4% for the egg, larva, pupa, and immature A. dimidiata, respectively, followed by at 22 degrees C and 19 degrees C, and the lowest at 31 degrees C. No larva and pupa could survive at 31 degrees C, suggesting that A. dimidiata was not resistant to high temperature. The development threshold temperature for egg, larva, pupa, and immature A. dimidiata was 13.21 degrees C, 17.12 degrees C, 14.76 degrees C, and 16.47 degrees C, and the effective accumulated temperature was 117.94, 870.88, 149.70, and 1442.75 day-degree, respectively. The results coincided with the fact that the A. dimidiata reproduced 2 or 3 generations a year in Xifeng area of Guizhou, Southwest China.

Toxoplasma gondii can live in the host for a long time relying on effective immune escape mechanisms and cause a chronic infection. Different antigenic molecules in the parasitophorous vacuole membrane, rhoptry and cytoplasm play an important role in evading the host's immune response. They can effectively help avoid the host immune response by inhibiting excessive inflammatory response and production of nitric oxide, affecting gene expression of some cytokines, depleting the specific immune substances, reducing the function of immune cells and so on. This paper summarizes the latest research advances in molecules related to the immune evasion of T. gondii.

In a long history of interactions between insects and plants, plants have developed various anti-insect compounds and defense signaling transduction pathways to defend against herbivorous insects, while insects have responded with sophisticated detoxification enzyme systems to protect against the toxicity of anti-insect compounds. In this study, the 2nd or 3rd instar of Spodoptera litura larvae were successively fed with the diets containing 0.5% soybean trypsinase inhibitor (SBTI) for six generations to evaluate the effects of SBTI and defense signaling compounds on the activities of detoxification enzymes carboxylesterase (CarE) and glutathione-S-transferase (GST) in the midgut and fatbody of the larvae. After fed with the diets, the CarE and GST activities in the 5th instar larvae increased significantly. The CarE activity in the midgut and fatbody of the second generation larvae was the highest, being 2.06 and 2.40 times, and 1.96 and 2.70 times of that of the control, and the GST activity in the midgut and fatbody of the fourth and second generations was the highest, being 7.03 and 11.58 times, and 5.71 and 3.60 times of that of the control, respectively. These induced enzyme activities decreased gradually when the larvae continuously grew with the SBTI-containing diets. In addition, when the S. litura larvae were pre-exposed to methyl jasmonate (MeJA) or methyl salicylate (MeSA) for 48 h or fed with the diets containing 0.5% SBTI, the activities of CarE and GST in the midgut and fatbody increased significantly, and, when the 2nd instar larvae were pre-exposed to MeJA and MeSA for 48 h, the effects of SBTI on the GST activity in larval midgut and fatbody were reduced.

Objective: To study the influence of host species on growth and development and active component content of Thesium chinense., Method: Plant morphology and active component content of T. chinense grown with different hosts were measured. The hosts were evaluated by using index-sum method., Result: Hosts significantly promoted the growth of T. chinense by increasing height, per plant weight, stem diameter, leaf area, the number of seed and haustorium,and decreased RW/SW ratio compared to without host treatment. Considerable differences existed among the effect of different host species treatments. Synthetical evaluation score of Gnaphlium affine was the highest (37), followed by Imperata cylindrical and Prunella vulgaris (36). It is suggested that they were superior hosts for T. chinense. But the scores of Triticum aestivum (25) and Eremochloa ophiuroides (17) were lower, so they were unsuited hosts for T. chinense., Conclusion: Hosts significantly promoted the growth of T. chinense. Considerable differences existed among the growth and development of T. chinense grown with different hosts, as well as active component content. Gnaphlium affine, Imperata cylindrical and Prunella vulgaris were superior hosts for T. chinense. While Triticum aestivum and Eremochloa ophiuroides were unsuited hosts for T. chinense.

In the process of invasion and development in host cells, Toxoplasma gondii causes acute and chronic infection. The parasite manipulates the host cell elaborately and integrated to keep a delicate balance between induction and elimination of the host cell immune reaction. It can then dwell and multiply successfully in the host cell, and hopefully be transmitted to a definitive host The host cell signaling is changed and regulated extensively by the parasite in the process, which plays vital roles in parasite invasion and development. This review shed light on the manipulation of host cell signaling by T. gondii infection in these aspects: (1) T. gondii secreted proteins which manipulate host cell signaling; (2) T. gondii modulates the innate and protective immune related host cell signaling; (3) T. gondii regulates anti-apoptotic reaction and cell cycle related host cell signaling; (4) T. gondii adjusts calcium relevant host cell signaling; (5) T. gondii manipulates cell structure reorganization relevant host cell signaling.

Objective: To investigate the natural hosts infected with Paragonimus sp. and identify the species of the parasite in selected counties/districts of Jinhua prefecture in Zhejiang Province., Methods: Three townships/towns were randomly sampled from each of the 9 counties/districts in Jinhua as pilot spots for the survey. Fresh-water snails were collected from the fields for examining cercariae. Crabs were collected and detected for metacercariae by routine technique and the metacercariae were fed to dogs purchased in areas free from paragonimiasis. Fecal materials of dogs and cats around the villages and streams where crabs were found infected were collected for examining eggs. The artificially infected dogs were sacrificed 55 d after infection to receive adult worms. The size of cercariae, metacercariae, eggs and adult worms was measured. After the DNA of the adult worm was extracted, PCR was used to amplify the COI gene and ITS2 gene of the mitochondria from the worms. Homology with relative strains/isolates was analyzed and phylogenetic tree constructed., Results: The survey demonstrated that the snail Semisulcospira libertina and the crab Sinopotamon chekiangense served as the first and second intermediate hosts respectively. Natural infection was found in Wucheng District with an infection rate of 0.2% (2/1,088) in snails and 76.7% (46/60) in crabs in Shafan township, and an infection index (II) of 2.0 in crabs, 0.1% (1/1,683) in snails and 53.0% (46/60) in crabs with an II of 0.9 in Langya town. The infection rate was 0 (0/575) in snails and 30.0% (18/60) in crabs with an II of 0.1 in Baimu township of Wuyi County. Paragonimus eggs were detected in feces of stray cats with a positive rate of 8.3% (1/12) in Shafan and 0.6% (1/17) in Langya. The size and morphology of the cercariae, metacercariae, eggs and adult worms were similar to those of Paragonimus westermani. The sequences of the COI and ITS2 genes were with 390 bp and 363 bp respectively, indicating a homology of 88.2%-98.2% and 86.5%-88.1% to the 11 strains/isolates of P. westermani recorded in the GenBank. The phylogenetic trees revealed that the parasite in Jinhua was in between the Minchin (Minqing, Fujian) strain and the Japanese Mie and Chiba strains., Conclusion: Natural paragonimus infection has been detected in snails, The parasite has been identified as P. westermani which is phylogenetically close to those crabs and cats in Jinhua. reported from Fujian Province and from Mie and Chiba of Japan.

In order to investigate the area distribution and host selection of Leptotrombidium scutellare in Yunnan Province, a field survey was carried out during 2001 to 2009, based on different geographic location, topography, climate and ecological characteristics. A total of 16 491 L. scutellare were captured from the body surface of 9 838 small mammal hosts of 7 families, 18 genera, and 30 species in 4 orders, accounted for 17.73% (16,491/92,990) of all chigger mites collected. L. scutellare distributed in 12 counties, more in the northwest and south of the Province. Although L. scutellare could parasitize on different small mammal species, most of them were on Eothenomys miletus and Apodemus chevrieri.

Objective: To understand the susceptibilities of Oncomelania hupensis snails to Schistosoma japonicum miracidia from different hosts., Methods: The Schistosoma japonicum eggs from different hosts, such as rabbits, cattle and mice were collected. These eggs were incubated for miracidia, respectively. Each snail from the same site was exposed to 5 miracidia of Schistosoma japonicum from different hosts. The infected snails were fed in the laboratory for two months. Then all the snails were dissected and observed under the dissecting microscope in order to know the infection rate of snails., Results: In the experiment group, the infection rates of snails infected with miracidia from rabbits, cattle and mice were 1.42%, 8.67% and 19.87%, respectively, the mortality rates were 29.5%, 13.5% and 24.5%, respectively. However, the infection rates of snails in the control group were 2.63%, 2.02% and 11.66%, respectively, and the mortality rates were 24.0%, 49.5% and 18.5%, respectively., Conclusion: The susceptibilities of Oncomelania snails to Schistosoma japonicum miracidia from 3 kinds of hosts are significantly different.

Taking the desert landscape in mid-eastern Ningxia of Northeast China as the background, eighteen patches of Caragana shrub lands (natural or manned) with the habitat types of manually-fixed sandy land, mobile sandy land, and silty-loam downland were selected as study sites to investigate the responses of three Caragana seed pest species (Kytorhinus immixtus, Etiella zinckenella, and Bruchophagus neocaraganae) to the host plant patch quality, patch area, and patch spatial pattern. The damaged rate of host plant by the pests had close relations to the patch quality, patch pattern, and the transferring capability of the pests. The responses of the pests to patch quality were affected by patch scale, and among the three habitat types, manually-fixed sandy land had the highest damaged rate, followed by mobile sandy land, and silty-loam downland, with significant differences among them (P<0.05). In small scale patch pattern, there existed definite correlations between the pest number and the patch area and its fragmentation degree. The decrease of patch area and the increase of the fragmentation degree reduced the damage rate of high transferring capability Etiella zinckenella (r = 0.365), but had less effects on low transferring capability K. immixtus (r = 0.160) and B. neocaraganae (r = 0.193). The strength of patch edge effect and the mutual complement of the resources around patches had positive effects on the population density of the pests.

Eothenomys miletus were captured in 19 counties of Yunnan Province. The distribution of species-abundance and the species-plots relationship between E. miletus and chigger mites were analyzed by using ecological statistic method. There were totally 40,052 chigger mites collected from the body surface of 1741 E. miletus. 111 species of chigger mites were identified. The species-abundance distribution showed that with the increase of mite individuals, the number of chigger mite species gradually decreased. Most mite species were rare ones. Species-plot relation indicated that with the number of mouse plots (samples of E. miletus) increasing, the number of chigger mite species increased. E. miletus collected quantity up to date still could not reflect the exact species richness of chigger mite.

Geostatistis methods were adopted to analyze the spatial pattern of Sitodiplosis mosellana (Diptera: Cecidomyiidae) at its different development periods and of its egg parasitoids mixed population (Tetrastichus sp. and Platygaster error; Hymoneptera: Eulophidae and Platygastridae). The aggregated spatial arrangements for S. mosellana cocoon, adult, and larva and for egg parasitoids mixed population could be well described by spherical model, spherical-exponential model, linear sill model, and spherical-exponential model, respectively. The spatial dependence range of S. mosellana cocoon, adult at initial emergence period, adult at peak emergence period, and larva, and of egg parasitoids mixed population was 53.6, 190.6, 154.1, 4.2 and 280.3 m, and the aggregation intensity was 30.5%, 95.6%, 96.3%, 14.9% and 95.3%, respectively. The simulated maps of the spatial distribution produced by Kriging model could intuitively analyze the dynamic changes of S. mosellana at its different development periods and of egg parasitoids mixed population from the two aspects of time and space.

Pine wood nematode Bursaphelenchus xylophilus is a notorious invasive species from North America, which can kill a large amount of pine trees and causes economic losses and ecosystem destruction. There is a close relationship and ecological interaction between B. xylophilus and its companion microorganisms. This paper listed the species of companion microorganisms, reviewed their important ecological roles in the propagation and pathogenicity of the nematode, and discussed the pine wilt disease from the viewpoint of microecosystem. The companion fungi can supply food for B. xylophilus, hold the cycle of second infection of the nematode, increase the proportions of dauer juveniles, and benefit the infection and distribution of B. xylophilus. The companion bacteria can enhance the pathogenicity of B. xylophilus, promote the propagation of the nematode, benefit the pinene degradation, and thereby, promote the adaptability of the nematode.

The innate immunity of invertebrate is one of the focuses of current research. The results show that fibrinogen-related proteins (FREPs) play an important role in invertebrates immune defense, which is considered one of the most important molecule to participate in immune defense. This article introduces the latest research on FREPs from three aspects, namely molecular structure, molecular polymorphisms and function. This will provide a theoretical basis to understand the innate immune mechanisms of invertebrates and co-evolution in host and parasites.

From October 2008 to May 2010, an investigation was made in a lac plantation in Yayi region of Mojiang County, Yunnan Province, China, aimed to understand the behavior of the monopolization of honeydew sources by ant Crematogaster macaoensis, and its effects on the sex ratio, mortality, fecundity, and lac production of Yunnan lac insect Kerria yunnanensis. The results showed that C. macaoensis fed and monopolized the honeydews around the clock during the whole life cycle of K. yunnanensis on the stick-lac, and the average number of visiting C. macaoensis ranged from 16.8 +/- 2.3 to 39.3 +/- 10.0 per 10 cm length of the stick-lac. C. macaoensis constructed shelters to prevent other animals from visiting the lac insect. C. macaoensis monopolization reduced the lac production of individual K. yunnanensi significantly, but had no significant effects on the lac production of whole lac insect colony. In addition, C. macaoensis monopolization reduced the mortality of K. yunnanensis significantly, and increased the percentage of K. yunnanensis females and the adult female fecundity. It was concluded that ant monopolization of the lac insect honeydew seemed to be beneficial to the lac production by the Yunnan lac insect.

Minimum amount of suitable habitat (MASH) is the minimum habitat area that a population requires to persist in a given environmental setting for a long time, being an important aspect of population viability analysis (PVA). In this paper, we estimated the MASH for wheat aphids, parasitoids, and hyperparasitoids in facility-based agricultural landscapes in Yinchuan Plain of Northwest China, based on the relationships between population density and habitat area, and by using regression analysis. It was found that the population density and growth rate were consistently inversely related to area, but the exact mathematical functions varied with different species, especially those at different trophic levels. The MASH values for Macrosiphum avenae, Schizaphis graminum, Aphidius avenae, Aphidius gifuensis, and Pachyneuron aphidis were estimated with a polynormal regression model of density-area relationship, and the results were similar to those estimated from an inverse relationship between population and area. The differences of MASH between trophic levels were significant. It was concluded that these species had different values of MASH, which reflected their different habitat requirements and their differences in body size, migration, trophic position, and habitat quality. For parasitoids, the highest parasitic rates always took place at a spatial scale of 800-1000 m2, which could be considered as the base of aphids control with parasitoids, while the difference of MASH among trophic levels could be used to suppress the pest population.

Cryptosporidiosis is a worldwide zoonotic disease, and Cryptosporidium is coccidia-like parasite that develops in epithelial cells in digestive and respiratory tracts of human and animals. This review summarizes the specific function structure of Cryptosporidium, nutrient uptake, transport, metabolism, and the impact of Cryptosporidium on host nutrient absorption.

Toxoplasma gondii is a ubiquitous, obligate intracellular protozoan parasite in human and animals. Chronic infection with this parasite is likely one of the most common infection in human. Following invasion of host cells T gondii resides within membrane-bound vacuoles known as parasitophorous vacuole (PV), which can protect the parasite from the endosomal acidification and lysosomal fusion of host cells. It plays an essential role in the whole parasitic process of T. gondii. This review summarizes the mechanism of PV formation and its function in the host cells.

Objective: To investigate the natural resources of the freshwater crab which can serve as the intermediate hosts of Paragonimus in Pinghe and Youxi of Fujian Province., Methods: Freshwater crabs were collected. The morphological characteristics of the crabs and the habitats were observed. The crabs were dissected and examined for the presence of Paragonimus metacercariae., Results: Two new species of crabs were described, named as Sinopotamon zhangzhouense sp. nov. and Bottapotamon youxiense sp. nov.. S. zhangzhouense sp. nov., holotype: male, carapace length 35.9 mm, breadth 42.8 mm, thickness 18.6 mm, collected from Pinghe County in southwest of Fujian. (24 degrees 14.206' N, 117 degrees 12.594' E). Distal segment of the first pleopod of male tended flattish, and showed palm nest-shaped concave, which divided into two point leafs, and longitudinal crack clearly identified in back. The end half of distal segment reversed to ventral outwardly. This species usually lived in the sluggish stream. The infection rate of Paragonimus westermani and P. cenocopiosus in S. zhangzhouense sp. nov. was 44.9% (35/78). B. youxiense sp. nov., holotype: male, carapace length 13.35 mm, breadth 16.63 mm, thickness 7.20 mm, collected from Youxi County in central Fujian (26 degrees 10.558' N, 118 degrees 22.012' E). The first pleopod of male was in slightly flat shape, ample and developed, as bow-like uplift. This species usually lived in the relatively flat terrain of stream. The infection rate of P. skrjabini metacercariae in B. youxiense sp. nov. was 92.1% (58/63)., Conclusion: Two new species of freshwater crabs (S. zhangzhouense sp nov. and Ryouxiense sp. nov.) serving as the intermediate hosts of Paragonimus have been described.

Some of the Chinese names involved in the cestode life cycle were not in coincidence with that of the Latin terms and their definitions, and may be imprecise in application. The term of metacestode has been misled into defining that is the larval stage in intermediate hosts or the infective stage to definite hosts; there was no specific Chinese term for sparganum which used to express it with same meaning and word as plerocercoid; the terms of oncosphere, procercoid and plerocercoid including cercomer were incorrectly translated; same meaning of hydatid and hydatid cyst were vaguely read in Chinese literature and protoscolex is concerning to a larva in the relevant literature. A renovated unified system of naming the various stages and phases of cestode development including adult in Chinese was proposed.

In the interaction of Plasmodium falciparum with human cells, sporozoite adheres to the receptor of the liver endothelial cell, then invades to liver. Merozoite binds to the surface of red blood cells, and invades to erythrocyte. The adhesion of membrane protein of the infected erythrocytes to the surface molecules of vascular endothelial cell in the vital organs leads to the obstruction of blood circulation eventually. The adhesion is mediated by interaction between parasite-derived ligands and the negative charged polysaccharides on the surface of host cells. This review is to discuss the molecular mechanisms in the host-parasite interactions.

The investigation was made in Luohe City of Henan Province from April to November, 2008. Cyclops were collected and plerocercoids of Spirometra mansoni were examined by microscope. Skin, muscle and internal organs of frogs and tadpoles were checked to detect spargana by naked eye and/or anatomical microscope. Feces of cats and dogs were collected to examine eggs after washing and precipitation. Spargana from tadpoles were collected to infect cats by oral inoculation. Results showed that the infection rate of plerocercoids in cyclops was 3.5% (3/85) and that of spagarna in tadpoles and frogs was 35.9% (120/334) and 16.8% (75/446), respectively. Among 3 cats and 31 dogs investigated, 1 and 6 (19.4%) were found infected respectively. Eggs of Spirometra mansoni were found in feces of cats 12 days after infection. 17 adult worms were found in the intestine of the cat on the 25th day. The habit of eating live tadpoles was found in local residents. The investigation reveals a high prevalence of Spirometra mansoni in the intermediate and final hosts. Eating live tadpoles seems a main reason of getting sparganosis mansoni.

Objective: To establish an tachyzoite-brachyzoite interconversion system for Toxoplasma gondii RH strain in vitro., Methods: COS-7 cells were inoculated with purified tachyzoites of T.gondii RH strain and cultured in vitro. The morphology of the cultured cells and parasites was observed and the total cellular RNA extracted on days 1 to 6 following the inoculation for detecting the expression of tachyzoite-specific protein (SAG1) and bradyzoite-specific proteins (BAG1 and SAG2C) using RT-PCR., Results: With the passage of time, the number of parasites in COS-7 cells increased but the proliferation rate was lowered gradually. The intracellular tachyzoites proliferated by means of budding and binary fission, which led to the changes in the alignment of the parasites in the cells from curved pairs, rosette or clustered, and semi-circular patterns to spherical encapsulation-like structures. These changes indicated the gradual transformation of the tachyzoites into bradyzoites. The expressions of the tachyzoite-specific SAG1 gene were detected throughout the 6 days of in vitro culture. The expression of the bradyzoite-specific BAG1 gene had been detected since the second day after the inoculation and SAG2C gene since the fifth day. Alteration of the culture condition resulted in gradual transformation of the bradyzoites into tachyzoites., Conclusion: An in vitro tachzoites-bradyzoite interconversion system for T.gondii has been successfully established, which provides the basis for further study of the mechanism of interconversion.

Objective: To understand the distribution of Angiostrongylus cantonensis foci in Guangdong Province for making surveillance program., Methods: Survey sites were chosen by strata sampling according to different geographic locations. Totally 22 survey sites were selected in four regions: East Guangdong, West Guangdong, North Guangdong and the Pearl River Delta. One or two administrative villages in each site were randomly selected for the investigation. Pomacea canaliculata and Achatina fulica collected from fields and other species of freshwater or terrestrial snails obtained in the restaurants and wet markets were examined for the third stage larvae by tissue grinding or lung examination. Rats were captured in the fields, and their hearts and lungs were dissected for adult worms. Rat feces were also collected for the detection of first stage larvae by water precipitation., Results: Large number of P. canaliculata was found in all sites. A. fulica was found in most surveyed sites. Totally 2929 P. canaliculata and 1354 A. fulica were collected with a larva infection rate of 5.9% (172/2929) and 16.5% (223/1354), respectively (P<0.01). The average prevalence among the regions was different (P<0.01) with the highest prevalence in Pearl River Delta (15.6%, 152/975), especially in Dongguan City of the Delta (34.7%, 78/225). 114 Cipangopaludina sp. and 252 Bellamya sp. were bought from wet markets of 9. sites. Larvae were found only in Bellamya snails from Luoding and Kaiping cities with an infection rate of 1.4% (1/70) and 3.3% (3/91), respectively. Totally 491 rats were captured in 9 sites including Rattus norvegicus, R. flavipectus, Suncus murinus, Mus musculus, Bandicota indica, R. losea and R. rattus, with an average infection rate of 11.4% (56/491). Adult worms were found in R. norvegicus, R. flavipectus and B. indica with a prevalence of 19.8% (52/263), 2.5% (3/118) and 10.0% (1/10), respectively. Thirty-four rodent fecal samples were collected in 7 sites and examined with a larva positive rate of 44.1% (15/34)., Conclusion: Foci of Angiostrongylus cantonensis are widely distributed in Guangdong Province as natural infection has been found in its intermediate and definitive hosts.

Dendritic cells (DC) are uniquely specialised for both antigen acquisition and presentation, linking innate and adaptive immunity. Great progress has been made in DC biology and function recently. In the field of schistosomiasis, studies have revealed that a DC phenotype is quite distinct to that of conventional activation. Understanding the interaction between schistosomes and DC is therefore not only addressing fundamental questions of DC biology and immunity to multicellular parasites but also opening the way to therapeutic manipulation of the immune system.

With the method of solid phase microextraction (SPME), a total of twenty-five volatiles were collected from rice plants induced by Nilaparvata lugens, and after applying azadirachtin fourteen of them were qualitatively identified by gas chromatography coupled by mass spectrometry (GC-MS), mainly of nine kinds of sesquiterpenes. Comparing with healthy rice plants, the plants attacked by N. lugens had more kinds of volatiles, including limonene, linalool, methyl salicylate, unknown 6, unknown 7, zingiberene, nerolidol, and hexadecane. Applying azadirachtin did not result in the production of new kind volatiles, but affected the relative concentrations of the volatiles induced by N. lugens. The proportions of limonene, linalool, methyl salicylate, unknown 6, zingiberene, and hexadecane changed obviously with the concentration of applied azadirachtin, while those of methyl salicylate, unknown 6, unknown 7, zingiberene, and nerolidol changed significantly with the days after azadirachtin application. Azadirachtin concentration, rice variety, and N. lugens density had significant interactions on the relative concentrations of all test N. lugens-induced volatiles.

Objective: To make an epidemiological investigation on clonorchiasis sinensis and relevant factors in the south of Hunan Province., Methods: One village from each of Lengshuitan District and Qiyang County was selected for the survey from November to December in 2006. Stool samples from villagers were collected and examined by modified Kato-Katz method. Questionnairing was performed for relevant knowledge and attitude among residents. The infection rate in animal reservoirs and intermediate hosts were detected., Results: A total of 586 cases with Clonorchis sinensis infection were found from 777 people with a prevalence of 75.4%. The average egg density was 451 eggs per gram (EPG) feces. Light, moderate and heavy infections occupied 85.5% (501/586), 14.0% (82/586), and 0.5% (3/586) respectively. Prevalence in males and females was 76.9% (316/411) and 73.8% (270/366) respectively with no significant difference (chi2 = 1.013, P > 0.05). Infections were found in all age groups, with the highest prevalence in the group of 70 to 79 years (85.7%, 30/35). By occupations, the prevalence was 82.5% (447/542) in peasants, 79.3% (42/53) in doctors, 73.7% (28/38) in teachers, and 73.5% (25/34) in local cadres. The infection rate was 17.4% (29/167) and 7.4% (2/27) in Parafossarulus seriatulus and Alocinma longicornis, and 69.2% (9/13) and 5.3% (1/19) in Carassius auratus and Cyprinus carpios respectively. Adult worms were found in all 3 dogs dissected. Over 80% inhabitants did not know that this disease can be acquired by eating raw fish. 95.6% (153/160) of the farmers and 56.7% (349/616) of the students had a history of eating raw fish. The water was contaminated with C. sinensis eggs by using untreated feces as fertilizer for farming and by scrubbing pail latrines in the ponds., Conclusion: The prevalence of clonorchiasis in human population is high in Lengshuitan District and Qiyang County of Hunan Province. Eating raw fish and using untreated feces as fertilizer are the most important epidemiological factors of the disease.