Snail inches way onto nation's agenda
(China Daily)
Updated: 2004-03-12 01:11

A lowly snail has inched its way onto the agenda of the annual meeting of the nation's highest political leaders and people's representatives.

It's not just any snail, however. It's the freshwater variety that can spread the potentially fatal schistosomiasis, a disease caused by parasites that attack the body and harm blood and liver in humans. It can also have devastating consequences on livestock.

It is spreading northward in areas south of the Yangtze River. Officials worry it could spread as far north to major population centres over the course of years if precautions aren't taken, officials say.

The spread is occurring because of a project under construction to transmit water from the Yangtze River to thirsty North China, including Beijing.

And now, warnings about the project move and the serious epidemic control task being undertaken along the Yangtze River are a hot topic at this year's session of the National People's Congress (NPC) and the National Committee of the Chinese People's Political Consultative Conference (CPPCC).

Premier Wen Jiabao, in his work report this year listed schistosomiasis, together with SARS and the HIV/AIDS, as diseases requiring better and immediate control efforts from his government.

In a proposal he authored, Xiong Sidong, a CPPCC member from Shanghai, called for more effective mitigation measures during the construction process of the large-scale south-to-north Water Diversion Project, China's most ambitious water optimizing programme.

The disease, caused by the schistosome parasite, is carried by freshwater snails.

When it attacks, schistosomiasis can become chronic in patients, who experience high fever, limb weakness and joint difficulties. Before people die, they lose the ability to work and function in society.

According to Ministry of Health statistics, in 2002 more than 810,000 Chinese were afflicted with the disease, but the current number might be over one million.

In the first eight months of 2003, a total of 492 acute patients were reported, with an increase of 27 per cent more than that of the same period in 2002.

Currently, there are 3.52 billion square metres of snail grounds in the seven provinces with a population of about 65 million people.

Frequent flood disasters brought by the Yangtze River in recent years, especially the deluge in 1998, is an important reason for the rapid spread of the disease which can infect both human beings and livestock, including key food producing animals like cattle and pigs.

Following the floods in 1998, farmers were asked to return their fields by the river to lakes and bottom lands for flood-prevention.

Such a measure makes these places, which have effectively controlled the snails through reclaiming land from marshes, become ideal sites for the snails to live.

The majority of the seven regions where the disease is not under effective control are located along the Yangtze River and include Central China's Hubei and Hunan provinces and East China's Anhui, Jiangsu and Jiangxi provinces. The other two regions are Yunnan and Sichuan provinces in Southwest China.

About 90 per cent of the marshes returned from land in the five provinces are expected to become snail breeding homes in the coming three to five years, said Wang Liying, an official from the Ministry of Health.

Meanwhile, the construction of large-scale water conservancy or irrigation works like the Three Gorges and the South-to-North Project will bring potential danger of the epidemic spreading, Wang told China Daily.

Wang was echoed by Xiong Sidong who said that the East Route, one of the three main water diversion lines of the South-to-North Project, is launched at or passes through the schistosomiasis-affected areas, such as Jiangsu Province.

Traditionally, the snails cannot lead a life in areas north of North Latitude 33'15 degree, or Baoying County of Jiangsu Province, a place more than 1,000 kilometres south of Beijing, Xiong said.

However, a on-the-spot investigation has proved the snails can live in areas north of Baoying County, another result of the global warming, Xiong noted.

So, if prevention measures are not effective during the construction process,the snails with schistosome could live and breed and be devastating.

The lack of enough government investment and a weak public health system targeting communicable diseases -- especially since the country started a market economy -- is another reason for the spread of the disease.

To strengthen the work of combating the disease, the State Council decided to reclaim the leadership of the effort at the end of February. Vice-Premier Wu Yi is the director.