A five-year-old boy underwent emergency HIV and hepatitis testing after pricking himself with a used syringe in an NHS hospital.
The used syringes were in a bucket placed under a sink
The youngster was found with his hand in a bucket of used needles in north London's Barnet Hospital in July 2003.
His mother Nasria Zalfaghari said he was finally given the all clear after a "tense and miserable" six-month wait.
Barnet and Chase Farm NHS Trust pleaded guilty on Friday to breaching health and safety rules and was fined £2,000.
The child, Babak, who suffers from autism and epilepsy, was having a heart monitor fitted in the hospital on 29 July, 2003.
'Remorse and regret'
He wandered off and found a bright yellow and orange "sharps" bucket containing used syringes on the floor under a sink.
Dominic Long, prosecuting for the Health and Safety Executive, told City of London Magistrates' Court: "The most serious risk was of infection with hepatitis B and HIV."
The child was immediately examined and put on an accelerated course of hepatitis immunisation.
Mr Long said the trust had failed to take simple practicable measures to ensure sharps boxes were kept away from children.
Defending the hospital, Simon Antrobus said the trust expressed remorse and regret over the incident.
He said the sharps boxes would normally have been placed on wall brackets.
Miss Zalfaghari said after the hearing: "It was a tense time and all the time I was hoping he would be okay but wondering if he had an infection."