Shifts in the Spatiotemporal Dynamics of Schistosomiasis: A Case Study in Anhui Province, China
The last half-century of schistosomiasis control activities in China have brought down the overall prevalence of human infection with Schistosoma japonicum to less than 10% of the level initially documented in the mid 1950s. Importantly, this reduction is not only, or even mainly, due to the advent of praziquantel in the 1970s and its subsequent dramatic fall in price. Instead, it is the result of a sustained, multifaceted national strategy, adapted to different eco-epidemiological settings, which has been versatile enough to permit subtle adjustments over time as the nature of the challenge changed. Consequently, prevalence has been falling relatively smoothly over the whole period rather than suddenly dropping when mass chemotherapy became feasible. Thus, early recognition of the huge public health and economic significance of the disease, and the corresponding political will to do something about it,underpinned this success. In addition, intersectoral collaboration and community participation played important roles in forming a sustained commitment to a working control strategy based on local resources. The unfolding story is presented from the early years' strong focus on snail control, by means of environmental management, to the last period of praziquantel-based morbidity control carried out under the 10-year World Bank Loan Project (WBLP). An important legacy of the WBLP is the understanding that a research component would sustain control measures and enable future progress. We are now witnessing the payoffs of this forward thinking in the form of a new promising class of drugs, improved diagnostics, and budding vaccine development in addition to novel ways of disease risk prediction and transmission control using satellite-based remote sensing. Different aspects of social and economic approaches are also covered and the importance of health promotion and education is emphasized. Issuing from the review is a set of recommendations, which might further consolidate current control activities, with the ultimate aim to eliminate schistosomiasis from the Chinese mainland.