Alessandro Petacchi has fallen victim to a virus [GALLO/GETTY]

Petacchi has won 24 Giro stages in his career. He contracted tracheo-bronchitis at a race in Turkey recently, Milram said in a statement.

Veteran sprinter Erik Zabel will replace Petacchi as the point-man in Milram's squad for the first major three-week race of the cycling season.

The Giro begins May 10.

"Until last night, even in this terrible condition, I was convinced I could race. But after talking it over with the team's general manager, Gerry Van Gerven, we decided not to rush back and prepare for the Tour de France instead in the best manner possible," Petacchi said.

Meanwhile, Petacchi is awaiting a verdict from the Court of Arbitration for Sport (CAS) concerning his use of an asthma drug.

The Italian Olympic Committee appealed to the CAS, asking sport's highest tribunal to annul a decision by the Italian cycling federation to clear Petacchi of any wrongdoing and impose a one-year suspension.

Petacchi registered a "non-negative" test for salbutamol after winning the 11th stage of last year's Giro.

Petacchi is authorized by the International Cycling Union to use a certain amount of salbutamol as part of his regular medication, Ventolin.

However, elevated levels of the drug can have performance-enhancing effects.