A year ago, 20 people were sickened with salmonella that was traced back to ground beef bought at Hannaford supermarkets.

The trail stopped there. Because of the practices and poor record keeping at the store, no one was able to find out the source of the contamination or take steps to prevent a much bigger outbreak.

A year later, American consumers are no safer from food-borne illness and the food safety chain is no more secure.

That’s because a full year later, the U.S. Department of Agriculture still hasn’t produced rules that would fix the communication problem the Hannaford recall exposed. At a time when the food supply chain is global and contamination in one spot on the planet could pop up thousands of miles away, this kind of weakness should not be tolerated.

What went wrong last year was meat from several sources was combined in a Hannaford butcher shop to grind for hamburger. When the outbreak was traced back to the store, there was no way of telling from the available records where the contaminated beef had come from.

If Hannaford employees had stopped mixing meat from various sources and cleaning the grinder between sources, it would have been able to determine where the bacteria had come from. Instead, after a couple months of digging around, the USDA ended its investigation, as it does about one third of the time, without finding out what happened.

Two out of three might be a good average for a baseball player, but it’s not good enough for a regulatory agency that is supposed to be protecting public health. A rule requiring everyone along the supply chain to keep accurate records should have been in place by now.

But it’s not. And the agency is not offering an explanation.

One possible reason is that new regulations were put on a slow track in an election year, when the president was being criticized for overregulating industry.

If that’s what happened here, it’s a sad comment on cynical politics getting in the way of sound policy.

Now that the election is over, there is no reason for delay. Everyone knows what should be done. If the USDA won’t impose this rule, Congress should.

The danger of a food-borne epidemic is too great to drag this out any longer.