Economist examines schistosomiasis in China

The Economist examines schistosomiasis in China. The disease, which is also called snail-fever, is the "world’s second-most prevalent tropical disease after malaria, affecting 207 million people of whom 726,000 are Chinese, according to the most recent official figures, from 2004," the Economist reports.

Although "Chairman Mao" ordered a "fierce, if rudimentary, campaign in the late 1950s when cases neared 12 million… subsequent efforts to eradicate the disease failed, despite the arrival in the 1980s of Praziquantel, a drug scientists say is highly effective in controlling the disease but fails to prevent reinfection," the magazine writes. However, earlier this year Chinese researchers said they had reduced infection rates to less than 1 percent in two villages by improving sanitation and using tractors instead of water buffaloes, a parasite host.

According to the Economist, "Nine-tenths of the world’s schistosomiasis sufferers live in Africa and studies have shown the disease leaves sufferers more susceptible to HIV infection." China has the potential to take a lead in addressing the disease in Asia and Africa, but first it must get to the bottom of its own problems in tackling the disease, experts say.

Some of the challenges of dealing with schistosomiasis in China include: ignorance about the disease and treatment. The Economist writes, "Some people refuse to take Praziquantel because they believing it will hamper their ability to work. Students and migrant workers often miss their chance of treatment. Villagers also rail against the government policy of using molluscides to kill the snails. They pay workers not to scatter the powder in the water as it depletes shrimp stocks and endangers eel farms."

In addition, "Deeper flaws are emerging," which include the high costs of tractors, the effect of the economic slowdown on migrant workers and "the impact of that emblem of controversy, the Three Gorges Dam," the Economist writes, adding that scientists are concerned that changes in water levels along the Yangzi river could create new snail habitats in areas where the disease did not exist previously. In the long term, experts say the solution is to find a vaccine (Economist, 6/18).