Chinese medical and veterinary workers are working to control an outbreak of echinococcosis, sometimes known as hydatid disease, a fatal parasitic disease affecting several herding communities in China.

Hydatid disease mainly affects herding areas in Gansu, Inner Mongolia, Ningxia, Qinghai, Sichuan, Tibet and Xinjiang. In 2012, about 50 million people were under threat from the disease. The government decided to get the disease under control by 2020.

"People can easily be infected by drinking contaminated water or through contact with infected dogs and other animals," said Zou Bin, a disease prevention worker in Shiqu County of Sichuan, one of the areas worst hit by the endemic.

With a population of 100,000, Shiqu is located on the southeastern part of the Qinghai-Tibet Plateau. About one tenth of the population of Shiqu are infected with echinococcosis, said Liu Lei, an official with the Sichuan Provincial Disease Control Center.

"We are collecting data on dogs and residents who need medication," said Zou.

"We plan to teach farmers and herders about the condition, give them free medicine, and closely monitor the spread of the infection," he said.

More than 70,000 residents in Shiqu have been screened since the end of last year, and about 20,000 remain to be tested, Liu said.

Work has been suspended for now, as the local people have headed out to the mountains to dig caterpillar fungus, a valuable ingredient in traditional Chinese medicine, he said. "We will proceed with the tests after the fungus season is over," he added.

At Shiqu, 184 new wells have been dug and about 66,000 people have access to safe water, he said.

In the past decade, more than 300 million yuan (about $46 million) was spent on prevention of hydatid disease in Sichuan. Patients who need surgery have their medical expenses covered.

The Qinghai Province has screened 1 million people, and found 7,300 people infected with the disease, 3,000 of whom have had surgery, according to Qinghai provincial center of disease prevention.