The wild water-rats and their relevance in the context of schistosomiasis mansoni in Brazil: what we know and recommendations for further research

Schistosomiasis is a parasitic and endemic disease in several parts of the world. Its mortality rate reaches alarming proportions, which makes emergency the control of this disease. In Brazil, only the species Schistosoma mansoni was adapted to the climatic conditions and to the presence of appropriate hosts. This species shows a life cycle involving mollusks Biomphalaria spp. and humans. However, it has been shown that wild rodents with semi-aquatic habits are capable to establish a productive infection of this parasite. In addition, they are likely also to be capable to spread the disease in endemic areas. Due to the selective pressure exerted by the successive infections in these animals, we may be watching the development of a new strain of the parasite, which is not yet fully defined and understood. With the intention of directing new studies to this problem, we tried to establish main lines of research to demonstrate the real importance of these wild rodents in the epidemiology of schistosomiasis mansoni in Brazil.