In efforts to prevent an outbreak of infectious diseases, especially intestinal diseases, rescue and relief forces and local authorities are dispatching disease control workers to villages affected by a magnitude-6.5 quake on Sunday.

"The priority of our work will lie in disease control as the next step in quake relief in the coming days, and we have already dispatched a large number of disease control workers to the quake-hit villages of Longtoushan township," said Ruan Lin, head of Ludian county's disease control and prevention center.

Roads to some villages have not yet been repaired so the workers often have to walk to their destinations, carrying disinfectant tablets and spraying equipment.

"As the temperature remains high and water has been contaminated after the quake, infectious diseases, especially intestinal diseases, put the quake-hit area under the biggest threat," Ruan said.

Kan Biao, an official with the Chinese Center of Disease Control and Prevention, said new and clean water sources are being sought.

"We have been telling the local residents to drink only boiled water and packaged mineral water, although the local water supply plant has pledged to put more water purifying facilities into use for the residents' convenience", Kan said.

In addition to water security, work to ensure sanitary conditions of public toilets ill requires a lot of time, money and human resources, Kan said.