Cockroaches: A Contributing Factor to Foodborne Disease

Features - Feature

October 31, 2010

Salmonella has been implicated in food recalls from peanut butter to dog food and, most recently, eggs.

While the root cause of the recalls is often unsanitary conditions, such conditions and pests go hand in hand in a chicken-or-egg-first type relationship.

In food and beverage processing plants, rodents tend to be the primary pest both introduced and controlled—sometimes to the neglect of other potential pest problems.

For example, the loathsome cockroach …

  • According to a University of Nebraska-Lincoln (UNL) publication, “Cockroaches have been found to be the cause of Salmonella food poisoning that can be life-threatening.” Noting that other pathogenic bacteria, including Staphylococcus, Streptococcus and coliforms, have been found in cockroaches, UNL explains, “This is because after feeding on contaminated food, disease bacteria can remain in the cockroach digestive system for a month or more. Later, human food or utensils can become contaminated with cockroach feces. It has been shown that Salmonella bacteria survive in cockroach feces for several years.”
  • The National Pest Management Association (NPMA) has published a white paper, “Pest Management in the Wake of the Peanut Corporation of America Salmonella Outbreak,” including reference to conducive cockroach conditions at PCA at the time of the 2009 recall. (Read the full paper at

The Problem.
“Cockroaches can spread 33 different kinds of bacteria,” said Missy Henriksen, NPMA Vice President of Public Affairs. “What we are seeing right now is that it really does underscore the importance of sanitation and proper pest management.”

Like all pests, and other living creatures, cockroaches seek three things for survival: food, water and shelter, Henriksen said. And with the haven that a food or beverage plant provides for all of these, a cockroach will take any opportunity to enter and make your plant its home and your food area its literal stomping grounds.

A Limited Solution. Prior to the 1990s, cockroaches were a greater problem in plants. But the advent of gel baits, which have more application potential, brought much of the problem under control, said Tom Dobrinska, Training Director for Anderson Pest Solutions. “Once the baits came out, that significantly knocked down the populations,” Dobrinska said.

However, the technological advance has a downside, that of an over-dependency on the baits to the neglect of sanitation and other integrated pest management practices. “I think there’s a false sense of security,” Dobrinska said, “so that can make [cockroach contamination] more of a threat.”

Entry and Harborage.
In processing plants, cockroaches are most likely to enter and be found in areas such as:

  • employee locker rooms, brought in from infested homes. According to the UNL manual, “Cockroaches are easily transported from infested dwellings to new places.”
  • stored goods areas/warehouses, having come in on supplies, both in food and packaging. “German cockroaches, specifically, love that corrugated cardboard,” Dobrinska said. These cockroaches can then transmit foodborne disease, or get into the food. “That’s why it takes due diligence wherever supplies are coming in.”
  • dark, hidden areas, entering through open doors or windows. “That makes a very easy entry point,” Henriksen said.

Although all can be modes of entry, the primary mode will vary by cockroach species. Oriental cockroaches, for example, may crawl under a door or through cracks. Sewer system repairs may send displaced American cockroaches up into buildings. German cockroaches usually come in with supplies or employees, rather than from outdoors. But in most cases, seeing one cockroach means there are more. Regardless of the species, “they are not single pests,” Henriksen said..

Communication is critical, particularly in 24-hour plants, Dobrinska said. The nooks and crannies of unsealed equipment can provide ideal harborage, but it can be difficult for a pest management provider to conduct regular inspections when the equipment is continually running.

Thus, “It is very important to have open communication among workers on the production line,” he said, adding that if any worker sees a pest or evidence at any time, it should be reported immediately to a manager, then to the pest management provider.

“Communication is absolutely imperative,” he said. “Even if there isn’t a cockroach issue, your company needs to be telling you how to implement a plan to be proactive.”

Proactive Sanitation.
Keeping cockroaches out and maintaining sanitary conditions so as to not facilitate cockroach survival can be simpler than eliminating a problem after an infestation is established.

As noted in the NPMA white paper, the FDA investigation of PCA revealed extensive unsanitary and harmful conditions: “From mold growing on ceilings to rainwater leaking into the production areas; from gaps large enough for rodents to easily access the facility to the presence of dead cockroaches throughout the plant, the conditions were termed unsanitary and harmful by FDA.”

As a result, from the moment the extent of the Salmonella food poisoning became public, “the issue of safety within food facilities became a front-page story.”

While acknowledging that the lack of pest management was not the central cause of the outbreak, the paper adds, “Yet, when one considers the presence of such conducive conditions for pests, the presence of cockroaches throughout the facility and the simple fact that Salmonella was transmitted, … poor or improper pest management practices could be viewed as a contributing factor in creating this crisis situation. ...The situational details reflect the need for strong, effective and consistent pest management practices within food facilities.”

The difficulty in many plants arises when priorities are established. “In food manufacturing, pest management is accepted as a necessity,” Henriksen said. But, in practice, the necessary financial and time commitment to proper pest management tends to fluctuate, with proactive pest prevention often relegated to a second-tier priority because of financial considerations.

However, she added, if pest management is viewed as anything less than a top organizational priority, it can lay the groundwork for significant future problems.

The ultimate goal in pest management, Dobrinska said, is to be preventive.

The presence of dead and live pests in the PCA plant is a reminder of the significant health risks. “No matter the size or severity of an infestation, a pest problem is not a situation to be taken lightly,” the paper said.

“The PCA crisis compels food facilities to reprioritize so that safety truly is first. One way in which to do so is to focus renewed efforts on implementing proper pest management programs.”

The author is Managing Editor of QA magazine. She can be reached at