In this earthquake-ravaged stretch of southwestern China, drinking water and vaccines are running short as health authorities face the daunting task of caring for millions of homeless.
People who lost their homes are packed into camps with only rudimentary sanitation as the government races to build makeshift housing in the wake of last week's 8.0-magnitude tremor.
Huang Xinyi, a 16-month-old baby, is covered with pimples that have appeared on his body since his family lost their homes and moved under tarpaulin.
"We had to spend 50 yuan (seven dollars) to buy some good medicine," says Xinyi's grandmother. "What's handed out for free to earthquake victims is just the most general stuff."
Health official Li Qiang does not hide his worries about the situation.
"All the bodies of dead animals and people were decomposing. Now the huge concentration of displaced people is also causing problems for hygiene and waste disposal," said Li, deputy director of the disease prevention authority in Sichuan province's Shifang district.
"And our public health services are no longer working. A big number of buildings are in ruins, computers are smashed and there's no electricity. So our alert system for epidemics is paralysed," he told AFP.
Adding to the fears, a vaccination campaign against meningitis and meningococcus has been stopped. Vaccinating young people against the highly contagious diseases was a priority, but the work ceased due to lack of refrigerators and transport equipment.
"We only have 10,000 vaccine doses left when we need 50,000," Li said. "If the campaign doesn't restart quickly, we run the risk of an epidemic."
No vaccines are available against hepatitis A, despite concern that the disease could spread among displaced people living in close quarters.
More than 5.2 million people have been left homeless by the May 12 earthquake, China's worst natural disaster in a generation. At least 74,000 people were killed or remain missing.
Authorities have issued orders for all medical workers to check for gas gangrene, a bacterial condition among injured people that can quickly lead to death. Doctors earlier said they had to perform 30 amputations due to the condition.
Drinking water is another concern.
"In the city, it's not polluted. But it's dangerous inside the rubble and in places where water pipes have been broken. And since our laboratories have been destroyed, we can no longer assess its quality," Li said.
Peasants ordinarily draw groundwater and the shallow level makes contamination easy. Health workers shout on loudspeakers urging people to use water decontamination tablets, which are distributed in the camps.
Zhou Fangyong, a 45-year-old woman, filled her bowls with water on the outskirts of the town of Mianzhu as her husband worked the pump.
"Not only do we have to pump water, but look at these pieces of material that we're living underneath. We made it ourselves to keep the water out. Tell the government that we need some tents," Zhou said.
Zhou and her husband are former peasants whose land was taken over by the government for 13,000 yuan (1,850 dollar) in compensation. Now they have also lost their home, reduced to splinters.
In the hope of reducing the chances of epidemics, volunteers who have come from across China are frequently disinfecting the displacement camps.
"There are about 50 of us and we spray three times a day," said volunteer Zheng Longfei, a member of China's Korean minority who came all the way from eastern Shandong province.
But he said his effort is only a start -- in the Mianzhu camp where he is volunteering, a staggering 80,000 people are living under tents.