An outbreak of salmonella poisoning has so far made 93 people ill in 19 states and the District of Columbia, according to the Centers for Disease Control and Prevention.
An internal memo sent to staff at the Food and Drug Administration indicated that spicy tuna rolls are "highly suspect," the Associated Press reported.
The memo also characterized the outbreak as "rapid and expanding in a number of cases."
Ten of those who became ill have been hospitalized, but so far, there are no deaths.
While health officials have not definitely identified sushi as the source of the outbreak, they have identified the strain of bacteria as Salmonella Bareilly, one of the less common types of salmonella. Salmonella poisoning is more often caused by the Salmonella Typhimurium and Salmonella Enteritidis.
Salmonella was also the culprit in an October illness outbreak that affected dozens of people who ate at certain Taco Bell restaurants in 10 different states. It was also linked to an outbreak that led to the recall of hundreds of millions of eggs produced at an Iowa farm in the summer of 2010.
"Salmonella is one of the most common pathogens you can get from eating raw or poorly cooked foods," said Dr. Thomas Hooton, professor of infectious diseases at the University of Miami's Miller School of Medicine.
E. coli and campylobacter are also often linked to undercooked foods.
Salmonella poisoning can range in severity from being completely asymptomatic to being severe enough to require hospitalization. Symptoms include nausea, vomiting, diarrhea and abdominal pain that appear within 8 to 72 hours after eating contaminated food.
"Salmonella poisoning is typically self-limiting and we don't normally treat it unless it's severe," said Hooton. "But infants, the elderly, pregnant women and the immunocompromised are more at risk for serious illness, so we are very concerned about these groups."