A Tail of Two Structures: Proteomic and Transcriptomic Analysis of Cercarial Heads and Tails of Schistosome Worms

Schistosomes require both molluscan and mammalian hosts for development. The larval stage, cercaria, exits the intermediate snail host and must swim to identify and invade the definitive mammalian host. The cercaria has two macrostructures, the head and the tail. The tail is lost after host invasion, whereas the head develops into a sexually dimorphic adult worm. Translation in the cercaria differs in each macrostructure with higher levels of translation in cercarial tails and little to no translational activity in cercarial heads. We compared the transcriptome and proteome of the cercarial head and tail and observed stark differences between the two macrostructures. We identified unique and differentially expressed transcripts and proteins, including multiple ribosomal components expressed in higher levels in tails than in heads, which may explain the differences in translation levels between heads and tails and reflect the weak correlation between transcription and translation in infectious cercarial heads and tails.

A Google Earth-based database management for schistosomiasis control in Zanzibar

Schistosomiasis remains a serious health problem in Africa. Although a strong, coordinated agenda for research on this disease has been in place for the last 50 years in Zanzibar, data storage, retrieval of survey data and management remain problem areas. We investigated the use of Google Earth (GE) in conjunction with a hand-held, global positioning system as a pilot project for managing schistosomiasis control. In this way, risk areas can be surveyed and followed up by visualizing both the distribution of human infections and that of the intermediate snail host together with environmental information. A platform with three spatial databases was created: i) Distribution of infected humans; ii) Distribution of the intermediate snail host in ponds (infected and not infected specimens); iii) Distribution of the intermediate snail host in streams (infected and non-infected specimens). The GE spatial database increased the efficiency of follow-up case treatment as well as snail control and contributed also to the discovery of previously unknown areas in need of snail control. We conclude that this platform is advantageous not only by being useful for management and visualization of spatial data, but also because it is easy to operate and available free of charge.