AN HIV scare forced an almost full jumbo jet to make an abrupt about-turn two hours into a flight from Sydney to Los Angeles yesterday afternoon.

The pilot informed 300 disgruntled passengers on board United Airlines flight UA816 that he would have to turn back after a woman was pierced by a syringe.

The woman is believed to have pricked herself when she put her hand into the seat pocket in front of her.

Cabin staff sealed off the area to attend to the woman.

On the return to Sydney the woman was led off the plane by medical staff.

Other passengers protested on learning that the flight could not be diverted to Auckland or Fiji instead of returning to Sydney.

They were further upset on learning that they would not be reboarding the flight until 10am this morning.

The passengers were put up at the Hilton Sydney Airport Hotel.

“Because of the risk of AIDS we had no alternative but to go back,” explained one of the flight attendants.

The incident is certain to lead to an investigation by United Airlines as to how cleaners missed the syringe.

With much of the fuel still on board, the pilot was forced to dump large quantities of fuel off the Australian coast.

The flight left Sydney at 1.15pm and returned at 5.45pm.

A Sydney airport spokesman confirmed that two hours into the United Airlines flight the captain radioed Sydney that they wished to return due to a medical emergency.

An Australian spokesman for United Airlines confirmed the drama involved a needle stick injury.

He said the passenger was given the choice of whether or not to return to Sydney and she elected to do so.

“That is as much as we know at the moment,” he said.