The Food and Drug Administration (FDA) found seven percent of all spices imported to the U.S. were contaminated with salmonella over three years of testing. Twelve percent of the spices also contained "filth" such as insect parts, rodent hairs, and excrement.

The findings were released Wednesday by the FDA after a long-lived effort to study the safety of spices.

In 2009 and 2010, black and red pepper from China India and Vietnam that was used to spice salami sickened hundreds of people, the Associated Press reported.

Salmonella is a bacteria-borne illness that can cause symptoms such as vomiting, diarrhea, fever, and bloody stool, MayoClinic reported.

Over the three-year study period, 749 shipments of spices were denied U.S. distribution because of salmonella contamination and 238 were found to contain filth.

Some of the spices that arrived at the border contaminated were either cooked or treated to eliminate infection. The FDA also said since spices are usually eaten in small amounts, the chance of getting sick from them is much slimmer than contaminated produce or other products.

The FDA said spice contamination is "a systemic challenge." They said most of the insects found in the spices were warehouse dwellers, which suggests the problem is more in storage practices than in harvesting, the New York Times reported.

The report also said some spices were produced "on very small farms where farm animals are used to plow, crops are harvested by hand, and spices are dried in open air," the AP reported. This can leave the spices open to contamination from animals, birds, and even humans.

The FDA is "not recommending that consumers stay away from spices," but suggested people cook their spices before consuming.

Michael Taylor, FDA's deputy commissioner for foods, said rules proposed earlier this year will aim to make the industry safer.  One way to reduce the risk of contamination could be to provide spice industry employees with better training, the AP reported.