INDIANAPOLIS — Food recalls across the United States increased 50 percent in the fourth quarter of 2011 and affected more than 80 percent more units compared with the previous three-month period, according to the quarterly ExpertRecall index published by Stericycle ExpertRecall. Conversely, the Index found that consumer product, pharmaceutical and medical device recalls decreased compared with previous quarters.

Undeclared allergens remained the leading factor in initiating food recalls, accounting for more than a third of food recalls in the quarter, according to the index, while concerns about Listeria contamination were the second-leading cause of fourth-quarter recalls, accounting for almost 20 percent of all food recalls listed on the Food and Drug Administration’s web site from October through December.

“Despite the drop in several other categories, the sharp increase in food product recalls is cause for concern,” said Mike Rozembajgier, vice president of recalls at Stericycle ExpertRecall. “Food recalls are challenging because they affect all consumers. Ensuring consumer safety during food recalls is complicated further when food is repackaged for storage or put in re-sealable containers, eliminating any chance of identifying the food in our homes as having been recalled.

“Another issue is that with so many recalls being initiated, consumers suffering from ‘recall fatigue’ may pay less attention to recall announcements than they should. In this current environment, manufacturers and retailers must take extra care to ensure that consumers are receiving the right messages about recalls and that they are encouraged to respond appropriately.”

The ExpertRecall index aggregates and tracks cumulative recall data from the Consumer Product Safety Commission and the FDA. The ExpertRecall index report is available online.