Jakarta, Indonesia ? Many of Indonesia’s 650,000 homeless earthquake survivors are living with deteriorating sanitary conditions, forced to wash with dirty water that infects wounds and spreads skin disease, doctors said Sunday.

Another peril loomed from a nearby volcano, which spewed lava and hot gases dozens of times Sunday.

There also was concern about bird flu in the quake zone, as the number of Indonesia’s human deaths from the virus mounted. Some of the homeless have taken shelter in chicken coops that aid workers fear could contain the disease.

Despite the hardships of day-to-day survival, farmers in the quake zone were returning to their fields to pick food, under pressure to earn money for rebuilding their shattered homes. Farming communities were among the hardest hit by the magnitude-6.3 quake that struck last weekend.

Most of the thousands left homeless are living in makeshift shelters – often just plastic tarps – with no toilets or running water.