Gartner has warned IT managers to update their business continuity plans in light of a possible outbreak of bird flu.

The analyst firm's report, Key Steps to Prepare for a Possible Avian Influenza Pandemic, stated that IT managers should make plans to keep the business running in the event of an outbreak.

"A pandemic would not affect IT systems directly, but is likely to cause considerable economic disruption through its impact on the workforce and on business activity," said report authors Steve Bittinger and Dion Wiggins.

The analysts added that IT managers can plan for such threats because many contingency strategies use IT to keep businesses running even during travel restrictions, quarantines or problems due to illness or fear.

"IT managers should ensure that their organisation plans for a possible outbreak whose course and consequences are unpredictable," the report warned.

Using the 2003 Sars outbreak as an example, Gartner said that companies may face restrictions on travel, a breakdown of the healthcare system and shortages of essential staff due to illness.

It further warned that supply chains could be affected, and that a general slowdown of business due to reduced spending and fear, uncertainty and doubt, could "reduce workforce productivity".

The authors advise companies to inform staff about preparation, and to assign managers to track the spread of bird flu and establish or expand home working facilities.

Gartner also recommends moving more transactional services online and preparing with partners to avoid disruption.

After the Sars outbreak Gartner produced three reports about the potential effects on business, and four after the 11 September terrorist attacks in the US.

According to the World Health Organisation a global bird flu pandemic could cause up to seven million deaths and leave tens of millions requiring medical treatment.