"We don't have a definitive answer yet," said Gib Parrish, a medical epidemiologist at the centers who has been keeping track of the deaths.

Those numbers are probably "lower than reality," said Rachel Gorwitz, a medical epidemiologist at the agency, because they only represent the cases that have been confirmed by laboratories.

A. James Ruttenber, a medical epidemiologist at the Centers for Disease Control, said the data were in question because of previous errors.

"To my knowledge, it hasn't happened in the recent past," said WilliamAtkinson, a medical epidemiologist at the Federal Centers for Disease Control.

That is what is presumed to have happened in Queens, although no one can be sure until medical epidemiologists complete their sleuthing.

The potential problem is simply too great to ignore, says Angulo, a medical epidemiologist at the Centers for Disease Control and Prevention.

"I think it is a serious problem," Dr. Larry Slutsker, a medical epidemiologist with the centers, said.

She was stationed in New York during her training as a medical epidemiologist at the Centers for Disease Control in Atlanta.

"They are powerful examples," said Dr. Thomas E. Novotny, a medical epidemiologist in the Federal agency.

More than 50 of the 131 cases occurred before the reservation outbreak, said Dr. Joel Williams, a medical epidemiologist at the centers.