Don’t forget biocontainment of disease when following biosecurity plans

The latest disease outbreaks fueled by new disease variants are good reminders that the best biosecurity plans must include strategies to keep disease contained within a barn as well as ways to prevent new disease outbreaks.

“We have to remember it’s not only bio-exclusion where we don’t want to bring in new, harmful disease onto a farm, but we also want to make sure that we contain diseases, so we are not transmitting it throughout the area or to any other barns within the system,” reported Erin Kettelkamp, DVM, Swine Vet Center.

“We have to worry about all the different movements that go on around the farm,” she explained. “Ultimately, we want to minimize any type of exposure rate. The fewer movement of either people, pigs or supplies, the better.”

Audits necessary

With fall arriving, Kettelkamp recommends hog farms conduct audits to make sure biosecurity plans cover all necessary areas and are being followed correctly.

“This time of year, it’s a good idea to have either a system’s audit or a veterinarian do an audit,” she said. “It gives another set of eyes on the farm to evaluate if we are doing what we say we are when following processes or make improvements.”

The audits should be conducted at least annually by a veterinarian or quarterly by an impartial employee or a veterinarian.

“We can’t always assume our procedures are being completed as we had them written down on paper,” she explained. “That’s why auditing all these processes is important.”

Kettelkamp conducts a variety of biosecurity audits ranging from a general farm audits to specific audits like truck washes and filtration systems. She offered strategies for making biosecurity plans stronger.

Control supply entry

Supply orders for the farm should be coordinated to reduce the number of deliveries to a farm. Instead of multiple deliveries in a week, supply orders are minimized to a couple a month.

For other types of supplies and equipment, the best strategy is dedicating the items to a specific farm.

“It is something like moving weigh scales or bringing in any other type of supplies such as those we plan to use on the farm for sampling,” she said. “Cost is a big concern. But if there is any way to have all these items dedicated to each site that’s good.”

If these items must be moved between farms, cleaning and disinfecting methods must be followed every single time.

“Other things to think about on farms is if they are filtered,” Kettelkamp said. “Continue to assess the filters and make sure it’s an airtight space.

“If focusing on sow farms, don’t forget about protecting the health of downstream pigs. We must be aware of where we put disease-challenged pigs or where we keep clean pigs. We also should evaluate biosecurity in a similar way as a sow farm, and the same with people movements.”

Control equipment movement

Another area of biosecurity concern is manure handling.

“We want to be diligent [and not hasty] about how we handle all that equipment,” Kettelkamp said. “Make sure to sanitize and move it between farms in a biosecure way.”

Ideally, the equipment should be segregated so anything used on a farm experiencing a disease outbreak is not then used on a clean farm. If this isn’t possible, then the focus should be on cleaning and sanitizing with downtime before the equipment is moved to other farms.

Similar rules also apply to feed mill trucks and other contractors entering the farm, like a service crew. Make sure a biosecurity audit covers all these activities, as well.

Truck washes

Kettelkamp has performed truck-wash audits that include environmental sampling to look for pathogen transfer.

“For truck washes, it’s best to use high-pressure and hot water as well as a large volume to remove the manure,” sha said. “It’s important to follow-up by applying a disinfectant to the entire surface of the truck.

“Common areas missed are ceilings on any decking in the trailer and tight corners in hard-to-reach areas. Keeping truck cabs clean, whether vacuuming or using disinfectants also shouldn’t be ignored.”

Kettelkamp also has seen problems with load-out chutes on farms. These areas need disinfecting.

While people errors continue to be a major cause of biosecurity breaches, audits will help reduce those slip-ups.

“Make sure audits are in place and we do what we say we are doing and pick up on any area of improvement before we have a disease outbreak,” she said.

“Biosecurity audits are tedious, and they should be. It’s a good thing to be careful.”

 

Dry fog with common disinfectants decontaminates supply rooms

Hog producers discouraged to learn foggers don’t fully disinfect a supply room should not close the door on the biosecurity method yet.

New research spearheaded by Erin Kettelkamp, DVM, with Swine Vet Center, found a better solution for disinfecting supplies in a hog facility.

“In previous research, all commercial foggers resulted in incomplete disinfectant contact to all sides of objects,” reported Kettelkamp, who earned her DVM from the University of Illinois. While at the university, she studied fogger decontamination efficacy and identified a new protocol for disinfection.

Particle size, disinfectants studied

Kettelkamp’s research considered two questions. The first was how the aerosol particle size impacted fumigation. The second question was the composition of the disinfectant.

“First, particle size does matter and the smaller the better,” she said. “We used a dry fog that is a particle under 10 microns. A fine mist is 100 microns, so this is a particle you can’t quite see. But when you have them in a high frequency, it creates a dense fog, which is important because those small particles move through the room. Instead of bursting at the first surface they come into contact with, the particles permeate the room and achieve disinfection.”

For the second question, Kettelkamp tested a combination of hydrogen peroxide and peracetic acid, which is used in food processing, dairy and beverage industries for disinfection. After testing different concentrations of both, she found one that inactivated pathogens.

“There is a ready-to-use formula…but it wasn’t strong enough,” she said. “We increased our concentration by doubling our hydrogen peroxide and quadrupling our peracetic acid.”

She also tested using hydrogen peroxide alone at the high rate, but it was not effective. Disinfection depends on peracetic acid in the mixture, she added.

Kettelkamp used a geobacillus indicator strip with a robust bacterial pathogen colony to test the results. She validated the results with a porcine reproductive and respiratory syndrome (PRRS) modified live virus vaccine and manure. The dry fog inactivated the indicator strip and PRRS while also disinfecting the manure.

Dry fog best

“If a producer wants to continue to use a fogging chamber, I recommend working with a veterinarian on using a type of fogger to decrease the particle size,” Kettelkamp said. “Hurricane foggers can be adjusted to smaller particle sizes and will be more effective (than larger sizes).

“The gold standard is a dry fog for best permeation throughout the room,” she added. “Specifically in this model, the hydrogen peroxide and peracetic acid worked well.”

Another benefit to a dry-fog system is it only needs an air compressor for operation. And after treatment, clean-up is easy because dry fog produces no residue or liquid pools that need to be cleaned up.

Recommendations

Based on her research, Kettelkamp reports complete disinfection by aerosol decontamination occurs with droplet sizes less than 14 microns. Optimal results require a droplet size that’s less than 6 microns, also considered a dry fog.

In addition, the disinfectant concentrations for decontamination must be hydrogen peroxide levels above 4.2 ppm and peracetic acid levels at 0.13 ppm.

“Fogging certainly isn’t the only method to decontaminate items as they come into farms,” she added. “Other methods such as hand spraying items and time and temperature to let items decontaminate are also effective. Fogging could also be used with other methods to achieve a really robust decontamination.”

For more information, you can view Kettelkamp’s research presented at the 2021 American Association of Swine Veterinarians meeting here:
Article
Presentation

Not making biosecurity improvements can cost more than making them

Featured Video Play Icon

Biosecurity ranks high on the list of concerns for swine veterinarians who want hog units tightened up to reduce disease. But the cost of new improvements can be overwhelming, according to Jordan Graham, DVM, MS, Swine Vet Center in St. Peter, Minnesota. He recommends reframing the question to what’s the cost of not making biosecurity improvements.

“It’s pretty easy for us veterinarians to walk into a farm and say here’s the 10 things where we have gaps in biosecurity,” Graham said. “Some of these measures are…costly. What we have to weigh is the cost of not implementing some of these things, especially in this part of the world where disease breaks are fairly often, given our pig density,” he continued.

“A lot of producers have learned how to function in that world of ‘I had a disease break and I learned to manage through it.’

“We try to monetize those disease breaks and say, if we could reduce that break, what could we gain back in production? But I would take it one step further and say what are you missing out on by preventing these breaks?”

Rank improvements by importance

Since there are many biosecurity options, Graham suggests producers first create a list of improvements needed for the farm and the cost of each. Rank this list by importance and keep it on file.

“Having that list with expenditures and stack ranked ahead of time helps us better prioritize when we go into a period [with] capital to expand on some of these,” Graham said.

One of the most expensive but effective biosecurity improvements is air filtration. But there are plenty of other biosecurity options that can make a big impact on the health of the farm.

For example, ultraviolet (UV) chambers to disinfect small supplies and lunches going in and out of a farm are very effective, he said. The chambers are relatively inexpensive and easy to use. Even a homemade UV chamber works well.

Mortality removal

Another example where an improvement can make a big impact is mortality removal.

“It’s a big issue on a lot of farms, especially older farms that aren’t set up to get sow carcasses out of a sow farm in a biosecure manner,” Graham said. “The dead drop or door…comes into contact with rendering or composting equipment, which is contaminated.”

Instead, he recommends setting up a system where the sows and other mortalities are physically out of the farm for the dead drop.

Biosecurity culture

Effective biosecurity also requires all members of the farm staff to follow biosecurity protocols.

“Biosecurity is a culture,” Graham said. “It’s never a question of are we going to pass things across the clean-dirty line or are we going to step outside.

“How do you foster that culture of biosecurity on the farm? It starts from the top down. People will act by example. If they see the owner come onto the farm and they’re not obeying the biosecurity rules that they have in place, you can bet they’re not going to do it when they’re not there.

“Putting a protocol in place is fantastic, but if we’re not auditing to that expectation, it will not get executed on a consistent basis,” he added. “The staff will understand that it’s important [enough] that you will be monitoring the processes you put in place.”

 

 

 

Maintain sound on-farm biosecurity with PRRS ‘season’ approaching

By Brad Leuwerke, DVM, MS

As we creep closer to autumn’s weather change, crop harvest, manure pumping, etc., we also sneak closer to what has become a predictable rise in new cases of porcine reproductive and respiratory syndrome virus (PRRSv) across the country.

For 10 years now, the Dr. Bob Morrison Swine Health Monitoring Project has shown that the swine industry experiences an annual rise in PRRSv cases over an epidemic threshold in the October to November time frame. If history has anything to say, a similar trend should be expected this fall.

Knowing that one of the biggest drivers of profitability for swine producers is reducing nursery and finishing mortality and culls, those swine producers who are able to keep PRRSv out of their herds will have an economic advantage.

As fall arrives and the number of PRRSv cases begins to rise, swine veterinarians will start to get a sense of whether there are any new or more pathogenic “strains” that may become the new virus to be on the lookout for as an industry.

The last two to three years have given rise to PRRSv 1-7-4 and 1-3-4; both viruses caused severe disease in sow herds, leading to aborted fetuses, piglet mortality and sow mortality.

The other challenge these viruses have presented is the difficulty in eliminating them from sow farms. The “traditional” 210- to 240-day closures designed to eliminate PRRSv from a breed-to-wean farm have not been as successful, forcing many producers to make a decision on whether to keep a herd closed longer in hopes of eliminating the virus or to reload the farm and restart the elimination procedures over again in an effort to not miss production targets.

Research on these viruses and how they are transmitted within a herd has shown that these newer strains are shed for a longer period and are shed in higher amounts from infected animals. There also is speculation that new viruses are able to change more quickly within a population. All of these factors have worked to decrease the success of PRRSv elimination in breed-to-wean herds.

The effects of an increasingly pathogenic virus also can be seen in growing pigs. PRRSv 1-7-4 and 1-3-4 infection in growing pigs continues to be severe, causing greater mortality with higher culling rates and increased treatment costs compared to PRRSv strains observed in the past.

Similar to the observations in sow farms regarding the timing of disease, the effects of PRRSv infection seem to extend to longer periods compared to past PRRSv strains. Nursery and finishing sites that are continuous flow struggle tremendously to eliminate the virus and should consider all-in/all-out or, at the very least, site depopulation to eliminate virus from these populations of growing pigs.

Prevention

The cornerstone of preventing new virus introduction still relies on biosecurity, biosecurity, biosecurity.

Even though newer strains of PRRSv act increasingly pathogenic, sound biosecurity practices — including clean/ dirty lines for site entry, controlled supply entry, organized (clean to dirty) personal movement, dedicated trailers, mortality composting, etc. — help limit virus spread from farm to farm.

Air filtration of breed-to-wean farms continues to be successful. Filtration hasn’t been 100% effective in all cases, but when looking at dense areas where sow herds were breaking multiple times each year, the reduction in the outbreak rate has been extraordinary. Updated technologies, including positive-pressure filtration systems and air conditioning, which reduces the amount of air that needs to come into the barn, continue to move the bar on what can be expected for preventing virus introduction into these farms.

A PRRSv vaccine remains an important tool available to producers for virus control. Recent additions of modified live PRRS vaccines on the market give swine producers further options for vaccines.

In many commercial sow herds, especially those in more densely populated swine areas, a modified live vaccine is used to help maintain immunity at least with the goal of lessening the impact a new virus introduction will have on the herd. In many of these cases, the herds and replacement gilts are vaccinated multiple times each year to maintain immunity.

In growing pigs, millions of pigs continue to be vaccinated for PRRSv (either prior to weaning or at some point while in the nursery). PRRSv vaccines continue to show the ability to reduce lung lesions for pigs that become infected with a non-vaccine strain of the virus. In addition, groups that are vaccinated and exposed to a field virus consistently show closeouts that have less mortality and a lower cull rate compared to nonvaccinated groups that become infected with field strains.

As an industry, we’ll start to see the benefits of new diagnostic technologies, including whole-genome sequencing, which will provide more insight than ever before regarding PRRS circulation and change within a population. Take, for example, herds that are unsuccessful at eliminating a resident PRRSv strain from their herd. Whole-genome sequencing will help determine if that virus continues to be the resident strain or if a completely new virus strain has been introduced into the herd.

It goes without saying that it has been and will continue to be an interesting time for all swine producers. The industry is already starting to make market pigs for June 2020. It’s paramount to keep PRRSv out of the herd. Those producers who are able to limit new virus entry will have a greater opportunity to keep reducing pig mortality and culls, leading to increased profitability.

PRRSv “season” will be here soon, so it’s important to emphasize that the biosecurity practices producers have used for years for PRRSv and other pathogens still apply.

Reprinted with permission of Feedstuffs.

Download the pdf