Chicken pox has rendered Saina Nehwal doubtful for next month's World Badminton Championship even though the ace shuttler remains hopeful of competing in the high-profile event at her hometown Hyderabad.

Saina, who won the Arjuna Award on Wednesday, has been suffering from mild fever since Saturday and it was only yesterday that she was diagnosed with chicken pox and was advised complete bed rest for the next few days.