Research and control of advanced schistosomiasis japonica in China

Abstract

Among the three main schistosomes (Schistosoma japonicum, Schistosoma mansoni, and Schistosoma haematobium) known to infect humans, S. japonicum causes the most serious pathological lesions. In China, only schistosomiasis japonica is transmitted. From the 1950s, massive epidemiological investigations and active control measures for schistosomiasis japonica have been carried out. At the early stage of schistosomiasis control program, there were about 12 million schistosomiasis patients, and about 5% of schistosomiasis patients belong to advanced patients, which was 600,000. After more than a half century of active schistosomiasis control work, the schistosomiasis situation has been reduced markedly. The nearest epidemiological investigation showed that, by the end of 2012, there were still 240,000 schistosomiasis patients with the descent rate of 98% and 30,000 advanced patients with the descent rate of 95%. This paper reviews the rich experiences of advanced schistosomiasis research and control in China, including that the epidemiology researches confirm there is a family aggregation of advanced schistosomiasis and advanced schistosomiasis patients have no significance to the schistosomiasis transmission in transmission-interrupted areas but still are an infection source in endemic areas; pathogenic mechanism researches verify that genetic factors and immunoregulation play important roles in the disease developing process; ultrasound image examinations are used not only in the diagnosis and differential diagnosis of advanced schistosomiasis but also in the guidance of treatment and evaluation of therapeutic effects and, furthermore, in the risk predictions of portal hypertension and upper gastrointestinal hemorrhage; clinical practices demonstrate that praziquantel can be used in most of advanced schistosomiasis patients, and the therapy not only can interrupt the schistosomiasis transmission somewhat but also is favorable for liver fibrosis improvement; the ascetic fluid concentration afflux is used in the therapy for obstinate ascites, and endoscopic varices ligation is used in the treatment of upper gastrointestinal bleeding, and both have good effects; hundreds and thousands of severe splenomegaly advanced schistosomiasis patients received splenectomy, and the long-term survival rate is more than 90%, most of them are basically cured from the disease and their labor force recovers, some dwarf patients begin growing and developing again, and some sterile women became fertile; the researches of traditional Chinese medicine in the treatment of liver fibrosis have made progress, such as Cordyceps sinensis showing some anti-fibrosis effect in the animal experiments and primary clinical trials; the animal experiments and epidemiological investigations indicate that schistosome infection is one of the carcinogenesis risk factors, especially for liver cancer. In conclusion, these experiences and lessons are plentiful and worth sharing with the peers of other endemic countries for reference.

The role of ST2 and ST2 genetic variants in schistosomiasis

“…S. japonicum is the only human blood fluke that occurs in China; most recent estimates suggest that hundreds of thousands of people experience chronic or severe clinical symptoms, including liver fibrosis, liver cirrhosis, liver portal hypertension, splenomegaly, and ascites 2, 3 . Thus, chronic infection and subsequent disease are responsible for a tremendous socioeconomic burden attributable to schistosomiasis in China.…”

Gut microbiota signatures in Schistosoma japonicum infection-induced liver cirrhosis patients

“…In conclusion, overall, we showed that gut microbial taxonomic pro les and diversity in S. japonicum infection-induced liver cirrhosis patients appear to be similar to the ones from age-matched healthy people. Therefore, in our context, patients with S. japonicum infection-induced liver cirrhosis present a "healthy" gut structure, which may partially explain the better prognosis of cirrhosis secondary to this infection, compared to cirrhosis of different etiology in China [26,27]. Future studies with much larger sample sizes across wider age ranges are, however, needed to further explore the relationship between S. japonicum infection-induced liver cirrhosis and gut microbiota and potentially disclose the possible mechanisms by which gut microbiota alterations in uence cirrhosis and/or vice versa.…”

“…Schistosomiasis diagnosis was performed using the Kato-Katz method to detect S. japonicum eggs in stool samples. Liver cirrhosis was diagnosed according to clinical and biochemical data and imaging exams (CT or B ultrasonic scans) [26,27]. Liver function was evaluated with the Child-Pugh classi cation system [28].…”

MicroRNA-21 Mediates the Inhibiting Effect of Praziquantel on NLRP3 Inflammasome in Schistosoma japonicum Infection

“…Schistosomiasis is a widespread zoonotic parasitic disease (1). So far, more than 200 million people have been infected with schistosomiasis worldwide, with 120 million showing clinical symptoms (2).…”