Schistosoma japonicum (S. japonicum)

Schistosoma japonicum is a parasitic trematode responsible for Oriental schistosomiasis, a debilitating disease endemic to parts of China, the Philippines, and Indonesia (WHO, 2023). Unlike other human-infecting schistosomes, S. japonicum is zoonotic, maintaining a broad reservoir in domestic animals like cattle and pigs, which complicates eradication efforts (CDC, 2019). The parasite's life cycle involves an intermediate snail host (Oncomelania spp.) and a definitive mammalian host, where adult worms reside in the mesenteric veins and produce thousands of eggs daily (PubMed: 28911101). The clinical manifestations of the disease, including liver fibrosis and portal hypertension, result from the host's granulomatous immune response to eggs trapped in the hepatic and intestinal tissues (PubMed: 30126456). Praziquantel is the primary drug used for treatment, acting by disrupting the parasite's tegument and inducing calcium-mediated paralysis, although its specific molecular target remains poorly defined (PubChem: CID 4891). Given the reliance on a single drug and the lack of a vaccine, research is focused on identifying specific enzymes and receptors within the parasite, such as thioredoxin glutathione reductase, for novel drug development (PubMed: 18305165).

Other names

Oriental blood flukeAsian blood flukeSchistosoma japonicum (Katsurada, 1904)

Praziquantel increases the permeability of the parasite cell membranes to calcium ions, leading to rapid contraction and tegumental damage, which results in the death and clearance of the worm by the host immune system (PubMed: 16352371).