A chandelier swings slowly in the breeze. Beneath it, raw sewage laps the sitting room floor. Something has gone very wrong in this small town on the coast of the Sea of Marmara. When the earthquake struck, the sea reclaimed some of the land.

"This was one of the most beautiful places in Turkey," said a man in a green face mask. "This is our home but now we're scared to stay."

The fear is generated by the threat of disease. There were rumours of cholera yesterday, but doctors said they had not seen any specific cases.

"We are praying that it doesn't happen," said a woman handing out basic medicines in the town square. "If it begins, it will spread beyond our control."

With millions living in chaos on the streets, health and sanitation have become a focus of the recovery effort. "Things are pretty bad," said Selcit Coban, a young Turkish doctor in profound need of sleep. "But they will improve," he added defiantly. "We are all working together.

Further down the coast, in Golcuk, the stench of death is often so strong that it stings the nostrils. Cars cruised the shattered town, distributing face masks against the smell of rotting bodies. Rumours - quickly denied by the health minister - have spread that the worst areas would be quarantined. "Epidemic threat!" the daily newspaper Turkiye screamed yesterday. "It is deeply imbedded in mankind to think that a dead body induces diseases in those alive," said Michel Thieren, of the World Health Organisation.

But it is the lack of clean water, lavatories, and medical care that could lead to things like diarrhoea, skin disease and respiratory infections, the World Health Organisation said, calling the danger from dead bodies "negligible". In one day, close to 1,000 people were buried in a mass grave in Adapazari, 95 miles east of Istanbul. Thieren has urged the authorities to use resources instead to treat the injured and care for survivors.

"I understand the panic, but it is not justified to use resources to take care of the dead bodies when you have so many injured," he said.

Medical teams on the ground also warn of sanitation problems and say that heat and stress can weaken survivors, leaving them more vulnerable to sickness.

"The stress on them exacerbates any ailments they may have," Dr Amnon Tsveili said at the Israeli field hospital set up in Adapazari.

He pointed to the woods nearby, where people are relieving themselves close to where they are sleeping. "This could be a real sanitation problem," he said.

"The children are especially prone because they are not aware of hygiene and the elderly are also susceptible. Once one member of the family gets ill, it can spread rapidly to the whole family," he said.

Turkey's Health Minister, Osman Durmus, insisted that steps are being taken to ensure adequate sanitary conditions. "There is no danger of epidemic," he said.

Medical teams, meanwhile, were immunising rescuers against typhoid and warning of health dangers for the masses of homeless, crowded into parks or along roadsides in the sweltering heat.

The smell of decay pervaded flattened towns like Adapazari, where at least 1,000 people died. Smashed sewage lines and the thousands of homeless living on the streets compounded the risk of cholera or other diseases spreading.

"We can't cope with this," Oguz Titiz, a doctor said. "Vomiting and diarrhoea started showing up last night, especially among children and the elderly."

Health services were in a shambles, despite the arrival of the Israeli medical team, which set up across the road from the quake-damaged state hospital.

"There are problems with organisation," said nurse Egemen Keskin, trying to nap on a lawn in her dirty white uniform. "Nobody knows what they're doing here. We've got all the aid we need but no one to supervise it. Everything is a shambles."

One Israeli, Col Giorah Martonovits, noted the lack of running water. "We are expecting sanitation problems," he said. Doctors said the tens of thousands with cuts or other open wounds suffered in the quake or while trying to rescue others were at special risk of infection from unsanitary conditions.

The prime minister's crisis office said medical teams have begun immunising rescue workers against typhoid, while others were picking up rubbish, spraying disinfectants and distributing chlorine tablets to be used for purifying water.

In Adapazari, 963 people were buried in a mass grave. The bodies were photographed so they could later be identified by families.

Turkey asked Islamic prayer leaders to call for national unity during their sermons today, which is the Islamic sabbath.

Labourers hacked at the heat-baked soil in a corner of the Bagcesme cemetery in Izmit. Almost as soon as a grave was completed, another earthquake victim was carried through the iron gates.

Hour after hour, funeral processions crept up the hill. At the summit, a panorama opens up of Izmit, where nearly every family has been touched by tragedy.

"We can't stop working," said a grave digger, Mehmet Ozturk. "It might be disrespectful during funerals, but we have no choice."

More than 40 victims have been laid in new graves, their names etched by pen into wooden markers. There is room for hundreds more. But there are 2,500 dead in Izmit and hundreds still missing.