Effective biosecurity requires multiple layers

Most hog farms have some level of biosecurity in place today, but simply outlining protocols doesn’t mean they’re effective.

Training employees on correct biosecurity procedures is another important step, but it doesn’t guarantee success. In fact, both can lend a false sense of security.

Numerous employees come and go throughout the day on hog farms, which can increase the risk of pathogen exposure to the animals.¹ Shower-in/shower-out requirements are commonplace, and what’s known as the Danish bench system — where a bench divides the clean/dirty sides and certain steps are required for entry — is gaining acceptance. However, there’s no research illustrating its effectiveness, said Cassandra Fitzgerald, veterinary student at Iowa State University.

In response, Fitzgerald set up a study to determine if installing a bench-entry system would prevent pathogen contamination from crossing the dirty side of employee entry to the clean side of the facility.

The study involved four female employees who were trained on biosecurity procedures and how to use the bench system. The test period involved 10 days with a solid-sided bench installed in the hallway immediately before the shower entry and 10 days without a bench.  Fitzgerald spread a fluorescent powder on the floor before the bench and shower entry for the respective treatments to simulate, and track, any pathogen contamination. A shoe rack remained in the same place throughout the study — between the powder and bench/shower entry.

She then measured environmental contamination each day at four locations:

• before the bench
• after the bench
• on the dirty side of the shower
• on the clean side of the shower.

Fitzgerald cleaned all areas every day to eliminate any residual powder. “However, that’s something a farm wouldn’t typically do,” she pointed out, “which would increase the contamination risk. The worker dressing and shower areas should be cleaned regularly.”

The results show that contamination was significantly (P <  0.05) lower directly after the bench when used but not for any of the other areas. “The bench entry inconsistently reduced the level of contamination, highlighting the need to focus on compliance and execution,” Fitzgerald said.

She noted that employees frequently touched the bottom of their shoes, transferring contaminants to their hands, which then spread further. Also, personal clothing, such as pants that drag on the ground, can increase contamination.

Beyond compliance, Fitzgerald said the study also highlighted the importance of layering biosecurity practices.

¹ Fitzgerald C, et al. Comparison of Standard and Bench Entry Protocols for Prevention of Environmental Contamination Due to Personnel Entry in Commercial Swine Facility. Student Seminar, 48^th American Association of Swine Veterinarians’ Annual Meeting. 2017;59.