Test results reveal little in salmonella outbreak

County health officer says definitive cause will not be determined

By Marissa Harshman, Columbian health reporter

Published:

Updated: October 24, 2012, 8:04 PM

 

New laboratory test results are providing little insight into the origin of a salmonella outbreak linked to an east Vancouver restaurant. Meanwhile, public health officials report their investigation costs have reached $44,000.

After shutting down the On the Border restaurant on Oct. 9, county health inspectors spent the day taking samples from surfaces throughout the restaurant to try to determine the source of the outbreak.

Dr. Alan Melnick, Clark County health officer, said Wednesday those tests all came back negative for salmonella.

Some of the surfaces had been cleaned by restaurant staff prior to health inspectors retrieving samples. That means the source could have been cleaned, or the bacteria was spreading by another method, such as a sick food handler or tainted food, he said.

“We’re never going to be able to say definitively what caused this,” Melnick said. “I wish we could all feel better with a definitive answer as to the cause.”

The restaurant’s management did not respond to messages left Wednesday by The Columbian.

Melnick said pinpointing the cause of food-borne illness outbreaks is difficult and rare.

The restaurant has been linked to 117 confirmed and probable cases of salmonella as of Wednesday morning. Public health staff interviewed those who got sick and, in some cases, their dining companions who didn’t. Those interviews and a statistical analysis revealed a handful of food items in common among people who got ill, Melnick said.

Those foods are guacamole, sour cream, lettuce, queso (cheese) and any of the restaurant’s appetizers, he said.

The problem, Melnick said, is those food items are included in numerous dishes on the menu. In addition, the restaurant ordered food twice weekly and discarded leftover freshly prepared items, such as guacamole, daily and other food twice weekly, Melnick said.

If a food item was to blame, health officials still have no way of knowing how it became contaminated with the salmonella bacteria.

Six food handlers are among those who were sickened by the bacteria. But health officials don’t know if the employees had the bacteria and spread it to customers or if they contracted the bacteria by the same method as the customers, Melnick said.

Without any definitive evidence, Melnick said he could only speculate as to the cause.

“I think it’s most likely cross-contamination,” he said.

Even without knowing the source of the outbreak, health officials believe the restaurant no longer poses a risk to the community.

Before reopening Oct. 15, staff and a third-party cleaning service cleaned the restaurant and sanitized everything with bleach. The restaurant also threw away nearly all of its food; health officials only allowed the restaurant to keep unopened canned food, soda pop in the soda machine and unopened bottles of liquor. Ill employees were prohibited from working until they produced two negative tests 24 hours apart.

Now that the restaurant is operating again, the health department will conduct an unannounced restaurant inspection soon, Melnick said. Health officials will continue to stop by unannounced every month for the next four months, Melnick said.

Investigation costs

Clark County Public Health is tracking the cost associated with the investigation at On the Border.

As of Friday afternoon, the price tag was up to about $44,000. Most of the cost is for regular staff time when health workers were redirected from other duties to help with the investigation. However, the total does include some overtime and standby pay, said John Wiesman, Clark County Public Health director.

Since the investigation began, the health department has devoted 682 regular staff hours, 94 overtime hours and 119 standby hours to the investigation, Wiesman said. Standby pay is a reduced rate paid to employees who may be called into work after normal hours, he said.

“The costs do add up quickly,” Wiesman said.

Clark County code holds restaurants responsible for the costs associated with outbreak investigations if “a disease outbreak is traced to a specific business and determined to be the result of improper hygiene or other unsafe practices.”

Since the On the Border investigation is ongoing, Wiesman said health officials haven’t determined whether the outbreak meets those conditions.