In a disaster of biblical proportions, one gruesome image among too many was the bulldozing of hundreds of unidentified bodies into mass graves in the Indonesian province of Banda Aceh. Officials there said the move was necessary "because of the smell and the health concern."
Not so, say public health experts. In fact the move directly contradicts advice from the World Health Organization (WHO), which stated in a communique following the disaster: "Bodies should not be disposed of unceremoniously in mass graves. This does not constitute a public health measure, violates important social norms and can waste scarce resources."
It adds: "Contrary to common belief, there is no evidence that corpses pose a risk of disease epidemics after natural disasters." Most infectious bacteria and viruses die within about 24 hours after death.
Nonetheless the WHO says people handling bodies should protect themselves from gastrointestinal infections and bloodborne viruses such as Hepatitis B. They could also catch tuberculosis if the bacteria are present in air from the lungs or fluid from the mouth and nose as the corpse is moved.
Oliver Morgan, an environmental engineer and public health expert at the London School of Hygiene and Tropical Medicine, has studied the risks after natural disasters. He says the only serious threat to the wider population from corpses comes from cholera, because dead bodies release the contents of their bowels.
"That's only a concern for the first day or so. Now we're a week into it that problem is no longer around. It's basically like someone having diarrhoea. If you come back a week later it's not going to be infectious," he said.
Even shortly afterwards the risk is low -- disaster victims are no more likely to be carriers than the overall population.
"The risks are all due to the survivors," Morgan says. "Survivors are going to be ill and potentially transmit diseases between each other." Most of the problems are caused by a lack of clean drinking water. Supplies are contaminated with sea water and infrastructure is smashed. Stomach bugs like salmonella and E.Coli will flourish and kill through diarrhoea and dehydration.
The scale of this disaster is unprecedented in modern times, but Morgan says some estimates of death from disease sweeping through survivors are exaggerated.