The public health significance and control of schistosomiasis in China-then and now

The description of schistosomiasis in China dates back more than two millennia. The disease caused social and economic hardship, and the rates of morbidity and mortality were high. In the mid 1950s, when China's population was approximately 600 million, an estimated 11.6 million people were infected with Schistosoma japonicum. Hence, a national control programme was launched, with an emphasis on intermediate host snail control by means of environmental management. Over the past 50 years, the national control programme has made great progress and praziquantel-based morbidity control became the mainstay of control. In 2000, the number of infected people had been reduced to an estimated 694,788, the snail-infested area has been abridged by over 75%, and the disease had been eliminated in five of the 12 previously endemic provinces. Between the mid 1980s and 2003, the criteria of transmission interruption have been reached in 260 counties (60.0%), transmission control has been achieved in 63 counties (14.5%), but the disease was still endemic in the remaining 110 counties (25.4%). Comparison between the number of cases in 2000 and 2003 suggests that schistosomiasis has re-emerged; an estimated 843,011 people were infected with S. japonicum in 2003. Here, we provide a short historical account of the pubic health significance of schistosomiasis in China, highlight the progress made to date with the national control programme, and place particular emphasis on the most recent trends. Finally, we discuss remaining challenges for schistosomiasis control with the ultimate goal of disease elimination.