A system for reporting outbreaks of food poisoning recorded more than 1,000 incidents that killed 22 people in 2008 and put nearly 1,300 in the hospital, the Centers for Disease Control and Prevention reported on Thursday.

While only a small number of food-poisoning incidents ever get reported, the data sheds light on where to focus food-safety efforts, the CDC said. Congress is currently fighting over how to fund the two agencies tasked with protecting the U.S. food supply—the U.S. Department of Agriculture and the Food and Drug Administration.

Norovirus, also known as winter vomiting disease, was the most common agent linked with outbreaks, accounting for nearly half of the outbreaks and 46 percent of illnesses, CDC said in its weekly report on disease and illness.

Overall in 2008, 1,034 outbreaks were reported, in which 23,152 people became ill, 1,276 were hospitalized and 22 died. In more than half the cases, officials were never able to find out what caused the outbreak.

“Among outbreaks with known pathogens, norovirus was the most common agent (49 percent of outbreaks and 46 percent of illnesses) and salmonella was the second most common (23 percent of outbreaks and 31 percent of illnesses),” CDC said.

Often the food culprit was never discovered, either, but the top three to be identified were poultry, in 15 percent of cases, beef in 14 percent, and fish in 14 percent.

CDC estimates that foodborne agents sicken 48 million Americans a year and kill 3,000 of them.

High-profile outbreaks of foodborne illness prompted Congress to pass the Food Safety Modernization Act, establishing the Food Safety Administration within the Department of Health and Human Services. President Obama signed it in January.

House and Senate funding bills give the FDA differing amounts to put it into effect. The House cut the FDA’s funding but on Wednesday Senate appropriators gave FDA a budget raise of $50 million.

Food processing and preparation is the main source of outbreaks, CDC said. “Many outbreaks result from contamination of food during preparation and service via unwashed or improperly washed hands of food workers who are shedding norovirus in their stools,” CDC said in the report.

“This often results in contamination of more than one food item. Contaminated environmental surfaces and infected consumers also lead to transmission of norovirus in food service settings. Additionally, norovirus contamination can occur during food production and processing, resulting in widespread exposure.”

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