With the death toll from a massive earthquake in China now above 67,000, the government aims to prevent new deaths by protecting survivors from possible floods and the threat of a disease outbreak. Jamila Trindle reports from Beijing.

Chinese rescue workers carry a body of an earthquake victim in the badly stricken town of Yingxiu, in Wenchuan County of southwest China's Sichuan province, 26 May 2008

Chinese health officials said Tuesday that they have begun the country's largest public health effort in recent history to guard against the threat of epidemics among survivors of the Sichuan earthquake.

Concern about possible outbreaks is rising not only because survivors are living in cramped, sometimes unsanitary areas, but also because the threat of disease is always higher in the summer. Officials say there have been cases of diarrhea, tuberculosis, and hepatitis among survivors, and they are monitoring the cases closely.

Ministry of Health official Chen Xian Yi says researchers have compared the current outbreaks with disease patterns before the quake.

Chen says that they have found that there are no more cases after the earthquake. In other words, he says, so far, there has been no big outbreak of disease.

While health workers focus on disease, soldiers are trying to evacuate an additional 80,000 people from around a lake that formed when a landslide dammed a river during the quake. With heavy rains expected in the coming days, there are fears the dam could give way suddenly, causing a flood that could endanger more than a million people. More than 70,000 people evacuated the area earlier.

Troops plan to blast openings the edges of the lake, to let the water gradually flow out from behind the dam.

The government says the quake created more than 30 such lakes. It also damaged nearly 70 man-made dams, which threaten communities.