With millions of tsunami victims in Southeast Asia living without clean water and proper sanitation, public health experts say the spread of disease is a serious concern.  There are some guidelines for people to follow as they struggle to cope without basic necessities. 
World Health Organization spokesman Oliver Rosenbauer says the spread of disease is the gravest threat facing people affected by Sunday's disaster.  

"Basically, what is important at the moment, the most crucial thing, is preventing diseases, and the best way to do that is by making sure people have access to safe and clean drinking water," he said.

For those who do not have access to a safe water supply, Mr. Rosenbauer recommends contacting relief workers and local authorities as they try to provide basic necessities to the survivors.

"Millions of water purification tablets have been sent out to the region, so there should be an infrastructure in place to get these distributed to the local populations, so local populations should check with their local authorities, with NGOs [non-governmental organizations] on the ground," he added. 

Because circumstances are different in each community, Mr. Rosenbauer says it is impossible for him to provide specific advice to people in need of food, water or proper sanitation.  He reiterates that relief workers and local authorities and health officials are the best sources of information. 

Yet, he says one fact holds true for the entire region, corpses do not pose a public health risk.

"When a person dies, any viruses or other pathogens that lives inside that body dies with the body almost immediately, so dead bodies do not actually pose a public health risk,? he explained.  ?Diseases do not spread from that.  If diseases do spread, it would be through the survivors and poor sanitation infrastructure."

He adds that people who handle corpses should work with local authorities to be sure basic guidelines are being followed.  He says such guidelines include wearing gloves and face masks and using body bags.

Although dead bodies do not threaten a survivor's physical health, Mr. Rosenbauer says exposure to dead bodies can have a negative effect on mental health.

"To the general population, dead bodies do not represent a public health risk,? he added.  ?I think what is much more important is that local customs are adhered to, that the families are given the opportunity to give a proper burial ceremony according to their local custom.  This probably has a greater psychological effect on populations because it is also very distressing to see all these dead bodies lying about, perhaps, and obviously there is also an odor associated with them."

The World Health Organization says between three million and five million people have been displaced by the earthquake and tsunami, and many of those individuals may be living without access to water, food or adequate sanitation.