"We understand and appreciate that there has been a … gap in communication, which results in school districts not getting information on a timely basis," Vilsack told lawmakers during a Senate Agriculture Committee hearing on child nutrition programs.

Vilsack's comments came during questioning by Sen. Kirsten Gillibrand, D-N.Y., who asked about a USA TODAY investigation published Tuesday. The newspaper reported that schools know almost nothing about where the food they serve comes from, even when government regulators are aware it may be contaminated.

Vilsack said the U.S. Department of Agriculture is expanding a "rapid alert system" to notify states and school districts of recalls that involve products served in school lunches.

The alert system had been used primarily to issue warnings about tainted food purchased by the federal government, which supplies 15%-20% of the food served in school lunches nationwide. Vilsack said the system also will be used to issue warnings about recalls or safety problems involving food that school systems may have bought on their own.

Many food recalls are overseen by the Food and Drug Administration, which shares responsibility with the USDA for regulating food producers and processors. Vilsack said officials are working to correct what he called a "lack of communication" between the two agencies.

The USA TODAY report highlighted the problem and its consequences. In one case, the newspaper reported, the FDA concluded in 2006 that a particular brand of tortilla held "the potential to cause illness," but that information never was shared with the USDA or school officials. The next year, more than 100 students and staff at schools in Racine, Wis., got sick after eating the tortillas.

In an interview Tuesday, Gillibrand called the newspaper's findings "very disturbing."

"We are not offering safe lunches to our children, and we have no way of knowing as parents and school administrators where that food is coming from and how safe that food is," Gillibrand said.

Using data kept by the Centers of Disease Control and Prevention, USA TODAY identified more than 470 outbreaks of food-borne illness in schools nationwide from 1998 through 2007. Those outbreaks sickened at least 23,000 children.

School nutrition expert answered your questions

Enlarge U.S. Senate Sen. Kirsten Gillibrand, D-N.Y., holds up the Nov. 17 edition of USA TODAY while questioning Agriculture Secretary Tom Vilsack during a Senate hearing on food safety.