The PCB has confirmed Shadab will now leave for London, where he will consult a doctor before joining the Pakistan squad in Bristol next week.
"I am delighted to know that the blood tests are negative and I can now return to competitive cricket," Khan said in a statement.
"I was always very confident that I would fully recover from the viral infection and will be available for the World Cup.
"It has been difficult to stay away from international cricket and watch Pakistan play outstandingly (against England) – both in Cardiff and Southampton. As a professional cricketer, you want to be part of such games."
Pakistan coach Mickey Arthur remains hopeful that the all-rounder will regain full fitness ahead of their World Cup opener against West Indies in Nottingham on May 31.
"Shadab's inclusion also balances what is a young but extremely talented squad," Arthur said.
"I understand it will take Shadab some time to be back at his brilliant best as he has not played cricket for a few weeks, but our first game is on 31st May and he has got two weeks to regain complete form and fitness."
(Reporting by Hardik Vyas in Bengaluru; Editing by Kevin Liffey)
