When You Need More Than 100%

By Lorraine Stevenson-Hall

Trucks and other vehicles are a main culprit in the transmission of farm animal disease, particularly in the swine industry. Even when cleaning and disinfection are 100% effective, vehicles are still a significant pathway for disease spread between farms.

The link between vehicle movements and disease breaks is undeniable. Aggregate data from the Swine Health Information Center (SHIC) Swine Disease Monitoring Report shows that the frequency of movement events closely corresponds to infection of PRRSV, PEDV, and PDCoV, in both the nursery and finishing phases.¹

Researchers set out to determine the exact risk posed by these movements by simulating the contact network between farms by vehicles.² Their scenarios factored in pathogen stability, which decreases over time, as well as the potential to eliminate pathogens on vehicles through cleaning and disinfecting.

Movements were analyzed for 823 vehicles associated with three swine production companies. Vehicles were categorized into six types based on their cargo: humans (crew), pigs-to-farms, pigs-to-markets, feed, undefined and all vehicle types (combined).

The analysis revealed that without effective cleaning and disinfection (0% efficacy), the number of farms potentially infected by vehicles transporting pigs to farms was 2,089 and by vehicles transporting pigs to market was 1,507. This is attributed to more frequent cleaning and a greater awareness of the risk of transporting live animals.

Even with cleaning and disinfection efficacy at 100%, vehicles remain a significant pathway for disease spread among swine farms.

In total, all vehicles combined could potentially infect up to 2,157 farms they had contact with in the network. With 100% cleaning efficacy, the number of farms potentially infected was reduced by 26% for vehicles moving pigs to farms and 43% for vehicles moving pigs to market.

The study concludes that additional measures, such as rerouting vehicles or increasing cleaning frequency, are needed to mitigate the risk of disease spread.

A review of biosecurity in pig farms³ also discusses strategies to reduce this risk. These include grouping trucks for transporting animals for a specific health status or production stage, as well as thorough and conscientious cleaning and disinfecting. However, the authors acknowledge that it’s nearly impossible to achieve cleaning and disinfection with 100% efficacy and reference a study⁴ showing that a high percentage of slaughterhouse trucks were positive for Salmonella after cleaning.

Farm Health Guardian boosts transport biosecurity. The system will send breach alert notifications if a truck or trailer does not stay within it’s assigned flow or group of properties, so you can take action to protect against disease risk. You can also verify compliance with truck wash, downtime, and other biosecurity requirements. Visit our website to learn more.