Detection of Opisthorchis viverrini Infection among the ASEAN Population in Thailand Using a Verbal Screening Test and Fecal Concentrator Kit

Background: Opisthorchis viverrini is a serious health problem in Southeast Asia. The infection is associated with cholangiocarcinoma. Therefore, this study was aimed to detect O. viverrini infections among the ASEAN population in Thailand. Methods: A cross-sectional study was conducted among 249 individuals from ASEAN populations in Thailand including Thai, Laotian, Cambodian, and Myanmar. Participants were screened using the O. viverrini verbal screening test (OvVST). Fecal samples were processed by the mini-parasep sf parasite fecal concentrator. Results: The infection rate of O. viverrini was 27.21%. The majority of infections was detected in females, in the age group 31-40 yr old, in the primary school education level, and in the occupation of labor. By country, O. viverrini infection was detected more often in the Lao PDR (30.77%). In screening for O. viverrini infection, OvVST had a high sensitivity (93.48%), specificity (86.70%), NPV (98.32%), and accuracy (87.95%). The PPV was 61.43% for OvVTS. The observed agreement was substantial for OvVST (k-value = 0.64). Conclusion: O. viverrini infections are still detected in ASEAN countries therefore large scale active surveillance is required. OvVST had a high sensitivity, specificity, and accuracy for screening the risk groups for O. viverrini

The Fifth Outbreak of Trichinosis in Korea

Trichinosis is a food-borne zoonotic disease caused by the nematode, Trichinella spp., and had been reported several times in Korea. Recently, there was an additional outbreak, involving 5 patients, the findings from which are reported herein. On 30 November 2010, 8 persons ate sashimi of the meat of a wild boar. Then, 2-3 weeks later, they complained of myalgia and fever. Unfortunately, muscle biopsy was not performed, but ELISA was performed using their sera. Two people among 8 were positive for Trichinella on the 34th day post-infection (PI), and 3 patients who initially revealed negative ELISA were additionally proved to be positive for trichinosis on the 42nd day PI. Hence, the confirmed patients of trichinosis were 5 in total in the present outbreak. They were treated with albendazole and discharged uneventfully. This was the fifth outbreak of trichinosis in Korea

Spatial Distribution of, and Risk Factors for, Opisthorchis viverrini Infection in Southern Lao PDR

The liver fluke Opisthorchis viverrini mainly occurs in Lao PDR and Thailand. Humans become infected through the consumption of raw or insufficiently cooked freshwater fish. Chronic infections may lead to severe liver (bile duct) diseases that eventually develop into a bile duct cancer with extremely poor prognosis. Current control efforts aim at preventing heavy morbidity and mortality. In recent years, spatial modeling, using data from well designed surveys, has been employed to better understand the distribution and determinants of parasitic diseases for guiding subsequent control. However, a spatial modeling approach has not been used for O. viverrini before. The purpose of the current study was to map the distribution of O. viverrini infection in Champasack province in southern Lao PDR, to identify risk factors of infection, and to predict the distribution at non-surveyed locations. We found that the risk of O. viverrini infection is higher for people living in close proximity to freshwater bodies, whereas the lack of sanitation sustained environmental contamination and transmission. High risk zones in Champasack province are concentrated in the Mekong River corridor, and hence control efforts should be targeted along the Mekong River

Significance of Cuscutain, a cysteine protease from Cuscuta reflexa, in host-parasite interactions

<p>Abstract</p> <p>Background</p> <p>Plant infestation with parasitic weeds like <it>Cuscuta reflexa </it>induces morphological as well as biochemical changes in the host and the parasite. These modifications could be caused by a change in protein or gene activity. Using a comparative macroarray approach <it>Cuscuta </it>genes specifically upregulated at the host attachment site were identified.</p> <p>Results</p> <p>One of the infestation specific <it>Cuscuta </it>genes encodes a cysteine protease. The protein and its intrinsic inhibitory peptide were heterologously expressed, purified and biochemically characterized. The haustoria specific enzyme was named cuscutain in accordance with similar proteins from other plants, e.g. papaya. The role of cuscutain and its inhibitor during the host parasite interaction was studied by external application of an inhibitor suspension, which induced a significant reduction of successful infection events.</p> <p>Conclusions</p> <p>The study provides new information about molecular events during the parasitic plant - host interaction. Inhibition of cuscutain cysteine proteinase could provide means for antagonizing parasitic plants.</p

Helminth and Intestinal Protozoa Infections, Multiparasitism and Risk Factors in Champasack Province, Lao People's Democratic Republic

Multiparsitism is a general public health concern in tropical countries, and is of particular importance in the Mekong River basin of Southeast Asia. Here, we report results obtained from an in-depth study of hepato-biliary and intestinal multiparasitism and associated risk factors in three settings of the most southern province of Lao People's Democratic Republic. Multiple species intestinal parasite infections were very common: more than 80% of the study participants harbored at least two and up to seven different intestinal parasites concurrently. Of particular concerns are the high prevalence of the liver fluke Opisthorchis viverrini (64.1%) and the moderate prevalence of the blood fluke Schistosoma mekongi (24.2%), as these fluke infections are responsible for severe hepato-biliary morbidity, including the bile duct cancer cholangiocarcinoma. Hookworm was the most common nematode infection (76.8%). We conclude that given the very high prevalence rates of parasite infections and the extent of multiparasitism, regular deworming is warranted and that this intervention should be coupled with health education and improved assess to clean water and adequate sanitation to consolidate morbidity control and ensure long-term sustainability

Developmental Transcriptomic Features of the Carcinogenic Liver Fluke, Clonorchis sinensis

Clonorchis sinensis is the causative agent of the life-threatening disease endemic to China, Korea, and Vietnam. It is estimated that about 15 million people are infected with this fluke. C. sinensis provokes inflammation, epithelial hyperplasia, and periductal fibrosis in bile ducts, and may cause cholangiocarcinoma in chronically infected individuals. Accumulation of a large amount of biological information about the adult stage of this liver fluke in recent years has advanced our understanding of the pathological interplay between this parasite and its hosts. However, no developmental gene expression profiles of C. sinensis have been published. In this study, we generated gene expression profiles of three developmental stages of C. sinensis by analyzing expressed sequence tags (ESTs). Complementary DNA libraries were constructed from the adult, metacercaria, and egg developmental stages of C. sinensis. A total of 52,745 ESTs were generated and assembled into 12,830 C. sinensis assembled EST sequences, and then these assemblies were further categorized into groups according to biological functions and developmental stages. Most of the genes that were differentially expressed in the different stages were consistent with the biological and physical features of the particular developmental stage; high energy metabolism, motility and reproduction genes were differentially expressed in adults, minimal metabolism and final host adaptation genes were differentially expressed in metacercariae, and embryonic genes were differentially expressed in eggs. The higher expression of glucose transporters, proteases, and antioxidant enzymes in the adults accounts for active uptake of nutrients and defense against host immune attacks. The types of ion channels present in C. sinensis are consistent with its parasitic nature and phylogenetic placement in the tree of life. We anticipate that the transcriptomic information on essential regulators of development, bile chemotaxis, and physico-metabolic pathways in C. sinensis that presented in this study will guide further studies to identify novel drug targets and diagnostic antigens