London, Nov 30 : Britney Spears refused to meet any of the X Factor's final five contestants over fears that they are 'toxic'.
The comeback queen snubbed the finalists to avoid catching any bugs from the wannabes.
The 'Toxic' hitmaker was scared that she would catch laryngitis, which could throw her 100 million pounds comeback into turmoil.
Contestants Diana Vickers, 17, and her rival Alexandra Burke, 20, almost pulled out of the show because of serious throat infections.
Cheryl Cole, 25, and Simon Cowell, 48, have also been battling severe flu.
Spears thrilled X Factor viewers with a raunchy performance of her new hit 'Womanizer', in what was her first UK appearance in five years.
However, she left it until the last minute to arrive for the show because of health fears.
Spears was put in quarantine before her TV appearance and the decision came after it was revealed Leona Lewis has also been sick since she performed on the show two weeks ago.
"Britney was so scared of getting ill she decided to fly in from Paris to perform and fly straight out again," the Daily Star quoted the source, as saying.
"She was worried about the cold weather but when staff found out about Leona and the contestants' illnesses, that was the last straw.
"She has a lot of money riding on this latest comeback and she could not risk getting ill as well," the source added.