New tremors today shook the region of southern Italy devastated by an earthquake last Sunday, as health officials expressed fear that dozens of bodies lying in open trenches could spread infection among the survivors.

There were no reports of new damage from the early-morning tremors, the strongest of which registered 3.5 on the Richter scale.

Meanwhile, the international relief operation continued in dozens of stricken towns and villages and icy winds, snow and rain that continued for a second day, preventing relief helicopters from reaching some of the isolated mountain villages hardest hit by the quake and turning tent cities for survivors into fields of ankle-deep mud.

Rescue officials found 15 persons -- including two young boys and an 80-year-old woman -- alive in the rubble today.

French technicians and Italian firefighters in Lioni pulled Carlo Campitello, 10, from the rubble. He had been buried beneath tons of debris for nearly six days without food or water. A 12-year-old boy found in the debris in Lioni last night died in a Naples hospital today.

In the ruins of the little mountain village of Sant' Angelo dei Lombardi, an 8-year-old boy and an 80-year-old woman were rescued alive 136 hours after the quake struck. They were rushed to a hospital in critical condition.

Rescue officials said more than 100 persons had been pulled out alive from under tons of rubble during the last week.

While relief efforts continued, health officials struggled with the welfare of survivors. Medical personnel sprayed disinfectant on rotting corposes to help prevent disease. Helicopters dropped packets of formaldehyde on rubble to slow the decomposition of bodies.

Health Minister Aldo Aniasi announced plans for mass vaccination to guard against typhoid and other diseases.

Health officials said the risk of disease was aggravated by the mud and filthy conditions in which thousands of people were living.

"The wind is blowing so hard there is no way to protect the children from the cold. They are crying constantly and we have nothing hot to give them," said Antonio Milano, who is living with his family in a tent outside Lioni in Avellino, the hardest his province.

The official death toll still stands at more than 3,000 dead, 2,000 missing and 8,000 injured, but some officials expect the death toll to rise above 10,000. About 250,000 people are homeless.