Flies buzz everywhere, as children play barefoot on a bamboo slat floor encrusted with chicken droppings. Nearby chicken feeding trays hold traces of rat waste.

Many in Pentong -- and in a broad swath of Java island -- lost their homes when a powerful earthquake struck a week ago, killing more than 6,200 people. Most survivors are living under plastic tarps or in any other shelter they can find.

"We are staying here because our houses were destroyed," said Parji, 60, the owner of one of two large chicken sheds where more than 50 people are living. Like many Indonesians, he uses one name.

Aid officials say they're worried the survivors could catch bird flu. The number of human cases has rocketed in Indonesia in the past month, and some cases have been reported in districts around the quake zone. At least 37 Indonesians have died.

"We are concerned that people using poultry sheds as shelter are at risk from avian flu and possibly salmonella infection," said Dr Yolanda Bayugo, health director in Indonesia for British-based aid group Merlin.

The risk may be low -- experts say the H5N1 virus is very hard for humans to catch, and the number of World Health Organization-confirmed cases is 49 among Indonesia's 220 million people.

But they also fear that if the virus mutates into a form easily passed between people, it could cause a pandemic that could kill millions.

Parji said Pentong's 1,000 people spent two nights in nearby mountains after the earthquake, worried that it would trigger a tsunami that would inundate the village -- even though the ocean is 10 kilometers (six miles) away.

A giant quake off western Indonesia in 2004 spawned the massive Indian Ocean tsunami, which killed 131,000 people in Indonesia. No tsunami followed last week's quake.