Of the world’s 4 million patients who suffer from Parkinson’s disease, nearly 1.7 million are in China, a survey by Chinese experts shows.

The survey, published in the latest issue of the medical journal Lancet, was conducted by Zhang Zhenxin, an expert at the Beijing Union Medical College Hospital, Xinhua reported Thursday.

Zhang found the incidence of Parkinson’s disease to be 1.7 percent among Chinese men over 60 years of age, and 1.6 percent for women, compared to the world average of 1 percent.

Many patients questioned for the survey said they had never received treatment of any kind, the report said.

A recent medical survey found that the disease affects some 1,000 of every 100,000 Chinese people over the age of 55, 12 times the rate recorded 20 years ago.

Experts ascribed the rapid increase to environmental pollution and overuse of chemicals such as pesticides.

"I am doing a project on the farmers’ incidence on Parkinson’s disease and found that the ones using certain kinds of pesticide are more likely to suffer from the disease," said Dr Jiang Yuping, from Huashan Hospital." It deserves attention from the government and the medical community."

About half of Chinese patients never go to hospital for effective diagnosis and treatment, especially in rural areas, doctors said.

Parkinson’s disease is a progressive nervous disease occurring most often after the age of 50, associated with the destruction of brain cells that produce dopamine and characterized by muscular tremors, slowing of movement, partial facial paralysis, peculiarity of gait and posture, and weakness.

There are 4 million Parkinson’s disease patients in the world, including 1.7 million in China. About 1 percent of Chinese over 55 suffer Parkinson’s disease and the incidence increases along with age.

Every year, there are 100,000 new patients in the nation.

"It is important to promote education to patients, family members and the medical industry. The disease can be controlled well if the patient start to take medicines in its early stage," said Dr Chen Shengdi from Ruijin Hospital. "Present medications can prolong the survival period from the previous five years to 10-20 years."

Wan guanghui, who has Parkinson’s disease, said he started to develop symptoms like walking difficulty and shaking in 1999. "I consulted many medical books and found that I will become a vegetable. So, I followed doctors’ direction and take medicine regularly," said Wan, a retired mechanic factory worker.