Clark County among first in U.S. to link salmonella outbreak to tuna

Clark County Public Health officials were among the first to identify a nationwide salmonella outbreak linked to tuna loins and tuna steaks.

Locally, the case began with five reports of illness to Clark County Public Health in late August. Since then, the outbreak has grown to 30 cases in seven states and led to a recall of a California-based company’s tuna products.

The outbreak includes six confirmed and two presumed cases in Clark County, said Dr. Alan Melnick, Clark County health officer.

The investigation is continuing at the national level by the Food and Drug Administration and the Centers for Disease Control and Prevention.

“The fact that little, old Clark County was able to be one of the first people to pick up on this ongoing outbreak really highlights the strengths of this system we’ve developed,” said Madison Riethman, an applied epidemiology fellow at Clark County Public Health, during a county health board meeting Wednesday.

Local health officials first learned of a possible outbreak on Aug. 29, when local laboratories reported five cases of salmonella, a bacteria that causes illness with symptoms such as diarrhea, fever and abdominal cramps. Typically, the department gets three to eight reports each month, Riethman said.

“The fact that we got five in one day was a big red flag,” she said.

But interviews with those sickened didn’t reveal any commonalities, Riethman said. They didn’t dine at the same places or attend the same event. The five cases didn’t appear to have any connection, she said.

But on Sept. 8, the state public health lab reported that additional testing revealed all five people were sickened by salmonella with the same DNA.

“They’re all the same genetic pattern, which tells us they’re all probably from the same place,” Riethman said.

Local health officials consulted with the Oregon Health Authority and learned there were an additional 12 people in Oregon who had been sickened by the same strain of salmonella. Interviews by health officials revealed most people sickened had eaten seafood, specifically sushi or some other form of raw fish, prior to falling ill, Riethman said.

Health officials in Oregon and Clark County visited all of the restaurants where those people ate – including three Clark County restaurants – and determined the culprit was likely raw tuna or raw salmon, Riethman said.

By Sept. 15, the case number had grown to 25 and included three cases outside of the region: two in Hawaii and one in New Jersey. Later, lab testing matched cases in Texas, California and Florida to the regional outbreak.

That’s when the CDC and FDA joined the investigation. And two weeks ago the FDA issued a recall of tuna products from the California importer linked to the outbreak, Riethman said.

Local health officials believe their efforts have curbed the outbreak in Clark County, but they continue to monitor the situation.

“We haven’t identified any new cases, so we hope we’ve at least stopped any ongoing exposures,” Riethman said.