UPDATE 1-Venezuela slows Amazon Indian swine flu outbreak

* Six deaths probed, officials monitoring situation

* Doubts cast on whether outbreak contained

* May have begun with event to mark voyage by Columbus (Adds NGO, Yanomami comments; details)

By Frank Jack Daniel

PUERTO AYACUCHO, Venezuela, Nov 9 (Reuters) - A potentially devastating outbreak of swine flu among the Yanomami Indians in Venezuela's Amazon rain forest appears to be contained for now after a rapid medical response in the remote zone.

Considered the largest isolated Amazon tribe, with a population of about 30,000, the Yanomami had limited contact with the outside world until 50 years ago. Illnesses brought by gold miners have hit them hard in the past.

Symptoms of swine flu -- possibly spread by outsiders at a government-organized event in mid-October -- showed up in more than 1,000 Yanomami, local health officials said. Six deaths are being investigated for possible links to the H1N1 virus.

Neris Villalobos, chief epidemiologist for Amazonas state, said the initial outbreak peaked at the end of October and the number of new cases has declined sharply.

"The action taken has been successful, although we cannot yet say that the situation is over," Villalobos told Reuters in Puerto Ayacucho, capital of Amazonas.