Bali Island, Indonesia  - An outbreak of rabies is spreading in Indonesia's resort island of Bali, officials said Wednesday.

Fifteen people have died and nearly 15,000 have been treated after being bitten by dogs since the outbreak began in November last year, according to Bali's Health Office.

Many Balinese fear the outbreak could hurt tourism on which the island depends.

The disease has now spread to seven of the island's nine districts despite the elimination of more than 28,000 dogs, said Ida Bagus Alit, head of Bali's Animal Husbandry Office.

"The low rate of vaccination coverage among dogs is making it difficult to stem the spread of the disease," he said.

Rabies is a viral disease most often transmitted through the bite of a rabid animal, especially dogs.

Alit said 180,000 dosages of vaccine provided by the government only covered 40 per cent of the dog population of more than 400,000 in the resort island.

The head of the island's Health Office, Nyoman Sutedja, said of nearly 15,000 people bitten by dogs, more than 13,000 had been given anti-rabies vaccine.

"Most of the victims were treated in hospitals and community health clinics," he said.

A virologist from Bali's Udayana University, Ngurah Mahardika, said the government's target to stamp out the disease in 2012 was unlikely to be met.

"The government's attempt to stem the outbreak has been dismal," he said.

Animal protection activists have criticized the government's move to eliminate dogs, instead of conducting an effective vaccination drive.

"We are confident that if 70 per cent of the dog population are vaccinated, the disease won't spread further," said the director of Bali's Animal Welfare Association, Janice Girardi.

Rabies has been reported on the Indonesian islands of Java and Flores, but Bali was free of the disease for decades until last year.

The World Health Organization estimated that more than 40,000 people die from rabies every year. Most deaths occur in developing countries. (dpa)