Evaluation of 4 intervention strategies to prevent the mechanical transmission of porcine reproductive and respiratory syndrome virus

Posted in: Air Filtration, Pork Insight Articles by admin on July 14, 2003 | No Comments

Four intervention strategies were tested on their ability to help prevent the spreading of PRRS. The four methods were: the use of disposable boots to prevent contamination of personnel footwear, the use of a boot bath to sanitize plastic boots, the use of plastic slated floor in the anteroom to prevent the spreading of PRRS to other peoples footwear, and the use of bag-in-a-box shipping methods to prevent PRRS virus contamination of the contents of a container destined for a swine farm. Ten tests were done with PRRS positive replicates as well as ten PRRS negative replicates were done. Swabs were collected from different sites and tested by a TaqMan polymerase chain reaction for PRRSV RNA and by swine bioassay to confirm the presence of infectious PRRS virus. The results showed that disposable boots, the boot bath and bag-in-a-box were all very effective in preventing the spreading of the PRRS virus. The slated floor did not do a good job in preventing the virus as it was an area where outside footwear could contact it and leave traces of the virus behind. This information is interesting although the study was not large or took statistical significance into consideration, therefore it is recommend as a pilot study rather than a biosecurity protocol.

Wastewater treatment system for pressure wash equipment

Posted in: Air Filtration, Pork Insight Articles by admin on June 12, 2003 | No Comments

Three new filtration systems are showcased in this publication by filtsep.com. They are:

• The PressureClear system from Turnkey Solutions Inc – A wastewater treatment system for pressure wash equipment
• The FEG™ Plus tubular membrane from Koch Membrane Systems – A high temperature/pressure tubular membrane system
• DelPore™ synthetic HEPA media, from DelStar Technologies Inc – A synthetic HEPA media that prevents dust overloading

The ‘Alaskan pipeline: A new model for evaluating aerosol transmission of swine pathogens

Posted in: Air Filtration, Pork Insight Articles by admin on May 29, 2003 | No Comments

There has been debate about the transmission of the PRRS virus through the air, some do not believe it is possible while other state that PRRS can be transmitted by aerosols. One test to prove if PRRS transmission by aerosols was possible involved pigs being held in  a transport trailer 30 meters from the side of a swine barn that had fans blowing in the direction of the trailer, and inside the barn there was PRRS positive pigs. There were no air samples that tested positive for PRRS inside or outside of the barn and obviously no pigs in the trailer became infected. This experiment didn’t shed any evidence towards proof  of PRRS being transported through the air, but the experiment did have a large number of variables that could have possibly manipulated the results such as the weather and the types of fans used. To make the experiment less subject to variables, Scott Dee used a 150m long PVC pipe with an air collector on one end and a fan on the other end. A  spray can of PRRS solution was sprayed into the fan side of the tube and collected on the other side. Air samples on the other side of the pipe were tested and were found to be PRRS positive. Then two pigs were held in a box on the non-fan side of the tube and sprayed with the solution, one of the pigs contracted the PRRS virus. This experiment was eye opening to the people who did not believe that the transmission of PRRS was possible by aerosols.

Evidence for local spread of porcine reproductive and respiratory syndrome virus

Posted in: Air Filtration, Pork Insight Articles by admin on November 26, 2002 | No Comments

It is has been proven that the PRRS virus can spread by direct contact of infected pigs with non-infected pigs. But there is also speculation that the PRRS virus can spread from indirect contact, such as by fomites, biological and mechanical vectors and by aerosols. Although tests done on indirect transmission haven’t produced clear results, but if it is a threat producers will have to improve there biosecurity guards to adapt. An ongoing study for virus surveillance was going on at the National Animal Disease Center with animals suspected to have the PRRS virus. These animals had their blood samples taken when the appeared to be infected with the virus. They consisted of 7 different herds, 6 of which were in close proximity to each other. Each herd was given a ranking in order of when they contacted the virus. 6 farms tested had the same isolate pattern while one had a unique isolate pattern. The farmers revealed in their interviews that they did not share equipment, their deads did not contact each other, and only one site had a vet visit in the previous 6 months. Only one herd was kept in a complete confinement system, while the others were in an open faced facility. The similarity of the PRRS virus found in all but seven of the farms was believed to be because of use of replacement animals from the same herd or the use of contaminated semen, not by indirect contact. The one herd that did not have the same strain of virus may have been because the virus made rapid mutations when it entered that specific farm that were different from the changes the other viruses went through. This research supports the hypothesis that PRRS area spread may occur but the method is unknown. When producers are building new facilities and deciding where to build them, PRRS virus area spreading should be considered.

Mechanical transmission of porcine reproductive and respiratory syndrome virus throughout a coordinated sequence of events during cold weather

Posted in: Air Filtration, Pork Insight Articles by admin on August 27, 2002 | No Comments

A field based model was used to assess the mechanical transmission of PRRS . The model involved a replica of a common farm workers behavior during cold weather, below 0^o C. The model used common fomites (boots and containers), vehicle sanitation, transport and the movement of the workers to track the spreading of PRRS. A strain of PRRS was put into carriers that were made up of water and snow and then put on the undercarriage of a truck. The truck then drove 50km to a truck was where the drivers boot came into contact with the carriers. Then the truck was driven another 50km to a simulated farm where the drive walked around and mechanically spread the virus in the anteroom. From there, common containers made contact with the floor drippings. Then all the pieces that came into contact with the carriers were sampled to track the spreading of the virus. This was replicated ten times. At several sampling points PRRS virus nucleic acid was detected in 8 of 10 replicates. In each of the 8 samples that did test PRRS positive infectious PRRS was detected on the surfaces of containers. All the control (non-inoculated) tests found no sign of PRRS. Leading researcher to believe that  mechanical transmission of PRRS can occur during coordinated sequence of events is cold weather.

PRRS virus area spread and aerobiology

Posted in: Air Filtration, Pork Insight Articles by admin on August 23, 2002 | No Comments

The disease PRRS has long been a problem faced by pork producers. The disease reduces productivity of the swine herd, and costs are spent on preventing and treating the disease, both of these factors cut into producer profits. The elimination of PRRS from a swine herd is only a temporary solution as the disease is almost always is able to penetrates swine dense areas, even with tightening and improving bio-security measures. Despite the impact of the disease, little is known about how it is spread and how it can be prevented. Aerosol transmission is said to be the way the disease travels, but this has never been backed with any empirical evidence. This paper attempts to show how breaking down the spread of the PRRS virus into smaller parts can make it easier to understand. It is suggested that to understand PRRS movement, we must first learn: Number of organisms aerosolzed by an infected pig over units of time, the rate of inactivation of airborne organisms under specific environmental conditions: temperature, light, relative humidity, dust, etc, the rate of dispersion of infectious particulates and direction of air flow, and the number of viable organisms required to infect the next susceptible pig. These factors are quantitative values making estimations possible although some of the data required must still be obtained. This information can be crucial, if a disease begins to spread predictions can be made about its range and preventive actions  can be taken.

La biosecurite a un nom: filtration

Posted in: Air Filtration, Pork Insight Articles by admin on December 27, 1999 | No Comments

L ‘elevage Maguer, selectionneur Large White a Elliant pres de Quimper dans Ie sud-Finistere, est I’une des tetes de pyramide en lignee male du groupe ADN. napprovisionne en cochettes LW les huit multiplicateurs du groupe, qui pro. duisent les fameux verrats LW x Pietrain, .mais aussi Ie nouveau verrat croise trois voies: LW x(Duroc x Pietrain) qui a ete presente pour la premiere fois cette annee au Space (voir aussi I’article sur I’inauguration de la troisieme station de production de verrats d’ADN. Cette station permet au groupe.

Bien gérer l’introduction des sujets de remplacement : DU LA PROBLÉMATIQUE SRRP

Posted in: Air Filtration, Pork Insight Articles by admin on September 20, 1999 | No Comments

L’introduction d’animaux de remplacement constitue toujours un risque sanitaire. À cet égard, le virus SRRP représente un défi particulier. En effet, non seulement certaines souches de ce virus peuvent causer des problèmes considérables, mais en plus, ce virus possède des caractéristiques qui en font un agent difficile à contrôler. Donc, une gestion adéquate du virus SRRP, bien que difficile, est essentielle au bon équilibre sanitaire des élevages.

Il est bien évident que les programmes d’introduction de sujetsde remplacement ne doivent pas se limiter au seul virus SRRP mais
doivent aussi prendre en considération les autres agents infectieux importants (Actinobacillus, Mycoplasme, virus GET, etc.). Cependant, en raison de l’espace imparti à ce document, seule la problématique spécifique du virus SRRP sera traitée.

The Role of Infectious Aerosols in Disease Transmission in Pigs

Posted in: Air Filtration, Pork Insight Articles by admin on August 31, 1999 | No Comments

There are many diseases that infect pigs by way of Airborne transmission. This paper reviews the general principles of the airborne pathway, including aerosol production, decay and inhalation. Also discussed is practical issues regarding aerosol sampling and sample analysis. Details of the aerobiology of porcine diseases, including foot-and-mouth disease, Aujesky’s disease, and respiratory diseases, are explained. Some other diseases are discussed based on the evidence gathered that they are transmitted by air. To prevent the spreading of airborne diseases, dust reduction, air filtration, air disinfection, vaccination should be considered.

The Role of Infectious Aerosols in Disease Transmission in Pigs

Posted in: Air Filtration, Pork Insight Articles by admin on August 28, 1999 | No Comments

Their are a number of infectious diseases in pigs that are transmitted through the air. This study reviews the general principles of the airborne pathway, including aerosol production, decay and inhalation. The study also discusses practical issues about aerosol sampling and sample analysis. The research describes in detail aerobiology of porcine diseases, including foot-and-mouth disease, Aujesky’s disease, and respiratory diseases. Also discussed is other disease that have potential to be transmiteed through the air. Some considerations suggestted for preventing airborne diseases in pigs are: dust reduction, air filtration, air disinfection, vaccination and the establishment of disease-free regions.