Never seen before? Opisthorchiasis and Clonorchiasis.

Parasitic diseases are relatively rarely diagnosed and treated in Europe. Therefore, European clinicians are not familiar with their clinical and imaging features. In an era of increased human migration, it is fundamental for clinicians to be able to identify such diseases. We have recently described the features of cystic echinococcosis, schistosomiasis, fascioliasis and ascariasis. Here, we report on the clinical and imaging features as well as on the current therapy options of infections by the small liver flukes: Clonorchis sinensis, Opisthorchis viverrini (Southeast Asian liver fluke) and Opisthorchis felineus (cat liver fluke) and other Opisthorchis species prevalent in South Asia.

Liver Fluke-Associated Biliary Tract Cancer.

Cholangiocarcinoma (CCA) is an aggressive cancer arising from epithelial cells of the bile duct. Most patients with CCA have an unresectable tumor at the time of diagnosis. In Western countries, the risk of CCA increases in patients with primary sclerosing cholangitis, whereas liver fluke infection appears to be the major risk factor for CCA in Asian countries. A diagnosis of liver fluke infection often relies on stool samples, including microscopic examination, polymerase chain reaction-based assays, and fluke antigen detection. Tests of serum, saliva and urine samples are also potentially diagnostic. The presence of liver fluke along with exogenous carcinogens magnifies the risk of CCA in people living in endemic areas. The "liver fluke-cholangiocarcinoma" carcinogenesis pathways consist of mechanical damage to the bile duct epithelium, immunopathologic and cellular reactions to the liver fluke's antigens and excretory/secretory products, liver fluke-induced changes in the biliary tract microbiome and the effects of repeated treatment for liver fluke. A vaccine and novel biomarkers are needed for the primary and secondary prevention of CCA in endemic areas. Importantly, climate change exerts an effect on vector-borne parasitic diseases, and awareness of liver fluke should be enhanced in potentially migrated habitat areas.

[Genomics and transcriptomics of the Chinese liver fluke Clonorchis sinensis (Opisthorchiidae, Trematoda)].

The review summarizes the results of first genomic and transcriptomic investigations of the liver fluke Clonorchis sinensis (Opisthorchiidae, Trematoda). The studies mark the dawn of the genomic era for opisthorchiids, which cause severe hepatobiliary diseases in humans and animals. Their results aided in understanding the molecular mechanisms of adaptation to parasitism, parasite survival in mammalian biliary tracts, and genome dynamics in the individual development and the development of parasite-host relationships. Special attention is paid to the achievements in studying the codon usage bias and the roles of mobile genetic elements (MGEs) and small interfering RNAs (siRNAs). Interspecific comparisons at the genomic and transcriptomic levels revealed molecular differences, which may contribute to understanding the specialized niches and physiological needs of the respective species. The studies in C. sinensis provide a basis for further basic and applied research in liver flukes and, in particular, the development of efficient means to prevent, diagnose, and treat clonorchiasis.

Clonorchiasis.

On Aug 21, 1875, James McConnell published in The Lancet his findings from a post-mortem examination of a 20-year-old Chinese man--undertaken at the Medical College Hospital in Calcutta, India--in whom he found Clonorchis sinensis in the bile ducts. Now, exactly 140 years later, we have a sound understanding of the lifecycle of this liver fluke, including key clinical, diagnostic, and epidemiological features. Developments in the so-called -omics sciences have not only advanced our knowledge of the biology and pathology of the parasite, but also led to the discovery of new diagnostic, drug, and vaccine targets. C sinensis infection is primarily related to liver and biliary disorders, especially cholangiocarcinoma. Clonorchiasis mainly occurs in east Asia, as a result of the region's social-ecological systems and deeply rooted cultural habit of consuming raw freshwater fish. The Kato-Katz technique, applied on fresh stool samples, is the most widely used diagnostic approach. Praziquantel is the treatment of choice and has been considered for preventive chemotherapy. Tribendimidine showed good safety and therapeutic profiles in phase 2 trials and warrants further investigation. Still today, the precise distribution, the exact number of infected people, subtle morbidities and pathogenesis, and the global burden of clonorchiasis are unknown. Integrated control strategies, consisting of preventive chemotherapy; information, education, and communication; environmental management; and capacity building through intersectoral collaboration should be advocated.

[Epidemiological characteristics and risk factors of hospital patients with clonorchiasis].

OBJECTIVE: To investigate the epidemiological characteristics and risk factors of clonorchiasis of hospital patients in Heilongjiang Province, so as to provide the evidence for formulating the control and prevention strategies. METHODS: A total of 2,359 suspected patients from human parasitic disease research institute of Harbin medical university were investigated. Totally 6,718 stool samples and 2 359 serum samples were tested by Kato-Katz technique and the enzyme linked immune method re- spectively. Meanwhile, the information of the patients was collected by questionnaires. RESULTS: Totally 513 suspected patients were infected with Clonorchis sinensis. The infection rate of the suspected patients was higher in the ≥29 group (P < 0.05), and the infection rate and positive rate of blood tests of the rural suspected patients were both higher than those of the urban suspected patients (both P < 0.05). The habit of eating raw fish and shrimp was the risk factor of clonorchiasis. CONCLUSION: Clonorchiasis is one of the main food-borne parasitic diseases in Heilongjiang Province. The habit of eating raw fish and shrimp is the risk factor of clonorchiasis.

Treatment of severe Clonorchiasis sinensis by endoscopic nasobiliary drainage and oral praziquantel.

AIM: To assess the therapeutic value of endoscopic nasobiliary drainage (ENBD) and oral praziquantel for severe Clonorchiasis sinensis infection. METHODS: Of the 84 Clonorchiasis sinensis-infected patients enrolled, 58 were treated with ENBD (as observing group, ENBD group), 26 received operations (control group, operation group). Both of the two groups were comparable in terms of patient's age, body mass index. Before and one week after treatment, the average diameters of common bile ducts were measured by ultrasound, and serum bilirubin, ALP, gamma-GT and ALT were detected by biochemical methods. After ENBD or operation, the patients took praziquantel for two days. RESULTS: Compared with the patients in operation group, ENBD patients in ENBD group had higher recovery rates of abdominal pain and fever as well as jaundice, quicker remission, smaller trauma, fewer complications and lower cost. CONCLUSION: ENBD combined with oral praziquantel is an effective and safe method for the treatment of severe Clonorchiasis sinensis.

Biliary parasites.

Parasitic diseases of the biliary tract occur frequently in tropical and subtropical areas and cause high morbidity and mortality. In general, neither the clinical presentation nor the general laboratory findings are sufficiently unique to raise the possibility of a parasitic biliary infestation in the mind of the surgeon. Once considered, however, the presence of a parasitic biliary infestation is easily confirmed. Most commonly this is accomplished by the identification of the parasite in stools or duodenal contents. Ultrasonography, CT and MRI are not only important in the diagnosis of parasitic biliary diseases but also in the follow-up and surveillance. ERCP is an excellent diagnostic tool for demonstrating the presence of parasites in the biliary tree. Furthermore, ERCP is also used in the therapy of biliary parasitic infestations and carries less morbidity and mortality than the surgical approach. Surgery is only indicated in complicated cases. Mechanisms that may be effective against parasites include: antibodies; cytotoxic T cells; T-cell-induced activated macrophages; natural killer cells, and a variety of cells that mediate antibody-dependent cell-mediated cytotoxicity and modulators of the immune system such as cytokines. Future research has to focus on the importance of these mechanisms for the immune evasion by parasites.

Endoscopy and biliary parasites.

Biliary parasites demand increased awareness among physicians all over the world in view of international travel and migration. Epidemiology, clinical manifestations, diagnosis, and treatment options for a variety of parasites are discussed in this article. Duodenofiberscopes play an important role in the diagnosis and treatment of these parasites.

Parasitic causes of pancreatic and biliary tract disease: a growing concern in a highly mobile population.

A leading cause of biliary tract disease and pancreatitis worldwide is parasitic disease. In the United States, increased global travel and the AIDS epidemic has led to a rise in the frequency of parasitic disease. Biliary disease and pancreatic disease secondary to parasitic infestation is relatively new in this country, with the first case being described in 1977. These diseases are no longer the exclusive realm of infectious disease specialists and require general practitioners and gastroenterologists to be well versed in the spectrum of parasitic pancreatic and biliary disease.

Clonorchiasis in Korea.

Since the first report on the incidence of egg positiveness of Clonorchis sinensis by Matsumoto in 1915, clonorchiasis has been recognized as one of the most important endemic diseases in Korea. Most of the works on clonorchiasis after then had been studied by Japanese workers until 1945. After the Korean War in 1950-1953, health problems of Koreans were extremely aggravated. This gave us attentions for the prevention of contagious diseases as well as parasitic infections in public health point of view. It was greatly recognized that not only ascariasis, hookworm infections, and trichuriasis, but also clonorchiasis and paragonimiasis constitute the important helminthic diseases in Korea. In the late 1950s, several Korean workers conducted studies of C. sinensis on its biology, epidemiology, pathology, clinical symptoms as well as treatment. Thereafter overall epidemiological surveys were carried out actively throughout the country since 1960s. From these surveys, it became clear that endemic areas of clonorchiasis are scattered all over the country along the Nakdong, Kum, Mankyong, Yeongsan and Han rivers. The most extensive and intensive endemic regions were found mainly along the Nakdong river. Since then, clonorchiasis has been one of the most extensively studied subjects during the past 30 years. The present review mainly deals with current results obtained by Korean investigators on the prevalence of clonorchiasis, as well as its biology, epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment, prevention and control.

[Clinical analysis and percutaneous transhepatic cholangiography drainage treatment of 25 patients with clonorciosis].

The clinical data of 25 patients with clonorchiasis were analyzed. Some features shown by B-mode ultrasonography and percutaneous transhepatic cholangiography (PTC) were discussed. Application of percutaneous transhepatic cholangiography drainage (PTCD) for treatment of complete biliary tract obstruction caused by clonorchiasis was introduced.

A preliminary study of clinical staging in clonorchiasis.

Antibody responses to infection with metacercaria of Clonorchis sinensis were studied in triplet cats. Elevated IgM antibody first appeared seven days after infection, followed by elevation of IgA and IgG. The peak titers of IgM and IgA antibodies were found at 3 weeks and 11 weeks, respectively. IgG antibody was elevated at 3 weeks and reached a peak, then a plateau at 13 weeks. Duration of antibody detection after infection was 1 week to 5 weeks for IgM, and 2 weeks to 28 weeks for IgA. IgM and IgA antibody titers decreased to normal level spontaneously without significant effect by the treatment. Using the animal model, the three clinical stages were classified according to the antibody patterns: i.e. acute stage, IgM(+) IgA(+) IgG(+); subacute stage, IgM(-) IgA(+) IgG(+); Chronic stage, IgM(-) IgA(-) IgG(+). Of 77 human patients with clonorchiasis, there were 3 (3.9%) patients who had subacute infection and 74 (96.1%) patients were in chronic stage.

Severe acute pancreatitis caused by parasites in the common bile duct.

Nine cases of acute pancreatitis due to parasites in the common bile duct (Ascaris lumbricoides 4, Clonorchis sinensis 5) are reported. Eight cases were discovered at laparotomy and one at postmortem. The indications for operation were worsening pancreatitis, sepsis or cholangitis. Decompression of the biliary system and removal of parasites resulted in the recovery of the eight cases operated upon. In endemic areas, all patients with acute pancreatitis should be screened for parasites. Antibiotics and/or antihelminthics should be given if they are found. Surgery is necessary for those with worms causing biliary or pancreatic obstruction who do not respond.