A strain of Salmonella commonly found in Thailand found its way to the United States in late 2008 and early in 2009 on the back of imported white pepper popular with Asians.  When it was all over, Salmonella Rissen–a serotype rarely found in the USA–would take the life of one person and cause infections in nearly 100 others in five states.

The story of how Salmonella Rissen came to America was one of several recent case studies presented last week at the International Association for Food Protection (IAFP), which held a four-day meeting at the Anaheim Convention Center.  Other case studies presented included the E. coli O157:H7 outbreak from raw cookie dough and two Salmonella outbreaks that involved drug-resistant strains.

The onset of infections from Salmonella Rissen in northern California and Nevada were dated back to December 2008 or even earlier, but the federal Centers for Disease Control and Prevention (CDC) in Atlanta first noticed the common PFGE pattern–or genetic fingerprint of the bacterium–on Feb 23, 2009.

An outbreak of the seventh most common strain of Salmonella in Thailand brought an early decision by the California Department of Public Health to activate its emergency response system.  It would eventually cause public health officials to use the courts to temporarily shut down operations at the company packaging the contaminated white pepper.

And while California has the largest number of outbreak victims and jurisdiction over the company responsible for the contamination, it would be Oregon’s ambitious testing program of anything that might be involved in an outbreak that produced the “smoking gun,” linking product and manufacturer.

By June 4, 65 people were infected with Salmonella Rissen in California, ten in Nevada, eight in Oregon, three in Washington state, and one in Idaho for a total of 87 cases drawn together by the common PFGE pattern.   

There was plenty to confuse investigators at the beginning, including the fact that in both California and Nevada, all he cases were in the less populous northern parts of the two states.

And while the focus went quickly toward some Asian restaurants, including buffet restaurants, patients in scattered hospitals were also getting sick.  Some of those were experiencing only mild diarrhea, not the usual explosive variety often associated with the pathogen.

When Oregon found the contaminated white pepper, the investigation was brought into focus.  It soon connected the hospital cases as all being owned by the same HMO using the same food vendor.   And the northern pattern of cases in California and Nevada was due to the fact that Union City, CA-based U.F. Union International Food Co, Inc., the manufacturer, had a sister company serving the southern areas of the state.

At Union International, where the Lian How brand was packaged, investigators found more than a mess.  Salmonella contamination was originally found in 63 of 391 samples taken at the facility, and when 25 positive samples were re-tested, all were found to be contaminated.

The FDA 483 form inspection report, issued July 24, 2009, showed the following:

-Failure to manufacture, package, and store foods under conditions and controls necessary to minimize the potential for growth of microorganisms and contamination:

-Private laboratory analysis results provided by the hired consultant revealed environmental samples collected from inside the facility were found positive for Salmonella.

-Ground white pepper was stored in open barrels beneath an unscreened roof vent.

-Failure to maintain white pepper grinding equipment in an acceptable condition through appropriate cleaning and sanitizing: An accumulation of dust was observed on multiple food contact surfaces.

-Barrels used to store while pepper were made of materials that allowed for proper cleaning and maintenance.

-Failure to clean and sanitize scoops used for repackaging spices in a manner that protected against contamination of food: Food residues and a thin film of dust were observed on the scoops.

-Failure to clean non-food contact surfaces in the white pepper grinding room and the adjacent hallway as frequently as necessary to protect against contamination: Accumulations of white pepper dust and brown stains were observed on multiple surfaces in the immediate vicinity of food contact surfaces.

-Failure to maintain pipes used to convey oil (food product) in a manner that protected against contamination: Oil was observed collected in pans below pipes and in a plastic bag tied around a pipe in the sauce and oil bottling room.

Food contact surfaces that returned positive for Salmonella included the inside of the white pepper hopper, the input chute for the grinder, and the exit chute for the grinder along with the ground pepper hopper exit chute.

Investigators continued to find Salmonella inside the facility even after it had been cleaned, and Union has ceased being a pepper packager.