Schistosomiasis

Abstract

Schistosomiasis is one of the most widespread and debilitating helminthic diseases. The immune system strives to be protective vis-à-vis Schistosoma infection, but the inevitable immunopathology may lead to fibrosis and organ dysfunction. Moreover, the skewing of immune response axis to polarized Th2 phenotype can impair resistance to other pathogens and has been associated with neoplasms, further complicating the clinical sequelae of schistosomiasis. Recent research has focused on subtle morbidities of schistosomiasis, including anaemia, malnutrition, and persistent inflammatory state which have significant impact on vulnerable populations such as growing children and pregnant females. Techniques and tools for diagnosing schistosomiasis either are cumbersome or lack sensitivity and specificity. Accordingly, many patients remain undiagnosed and receive no treatment. Currently, the only available drug is praziquantel (PZQ), the use of which in mass treatment raises concerns about development of drug resistance. PZQ also neither affects juvenile parasites nor prevents reinfection. Indeed, Schistosoma infection is a fascinating model for gaining insight about the mutual interplay between host and parasite factors, which ultimately determines the net pathology. Despite decades of intensive research on schistosomiasis, unresolved issues are still intriguing scientists; one of which is the development of a vaccine. Fortunately, however, significant progress has been achieved towards the elimination of schistosomiasis. Information provided in this review should help opening avenues for better understanding, management, and control of schistosomiasis.