A giant biotechnology firm has begun an intensive cleanup of a Boston plant to kill a virus that could infect drugs that treat genetic disorders, the firm says.

Genzyme Corp., the world's third-largest biotechnology company, has dismantled equipment and scrubbed surfaces with spore-killing bleach in an effort to kill the Vesivirus 2117 strain, which also showed up at the plant in November, it said.

The 28-year-old company, whose products are available in nearly 90 countries, also found the virus, which can affect the growth of cells used to make the treatments, at its Geel, Belgium, plant in September.

In Boston, it soon plans to wheel in "vaporizers" that will disperse clouds of vaporized hydrogen peroxide throughout the 185,000-square-foot production area, The Boston Globe reported.

"It kills all known living things," Mark Bamforth, Genzyme's senior vice president for corporate operations, told the newspaper.

The U.S. Food and Drug Administration, which is investigating, has not determined the contamination's root cause.

The temporary production standstill comes when inventories for the halted drugs, Cerezyme and Fabrazyme, "are not sufficient to meet projected global demand," Genzyme said in a statement.

Cerezyme treats Gaucher disease and Fabrazyme treats Fabry disease. Both conditions cause waste to build up in the body, swelling organs.

The drugs, taken intravenously about every other week, cost about $200,000 a year per patient, the Globe said.

Because of the temporary shutdown, drug doses to about 8,000 patients are being rationed, Genzyme said.

It did not say if it planned to recall any drugs already on the market.

The company said it was working with physicians, patients and regulators "to minimize the impact of this constraint."