Young Lyoo – PRRSControl https://prrscontrol.com Thu, 09 Sep 2021 07:18:02 +0000 en-US hourly 1 https://prrscontrol.com/wp-content/uploads/2018/04/favicon-45x45.jpg Young Lyoo – PRRSControl https://prrscontrol.com 32 32 Highly pathogenic PRRS strains https://prrscontrol.com/highly-pathogenic-prrs-strains/ https://prrscontrol.com/highly-pathogenic-prrs-strains/#respond Wed, 08 Sep 2021 13:59:57 +0000 https://prrscontrol.com/minimize-prrs-vaccination-stress-copy/ There are many HP-PRRSV cases in China and Southeast Asia. And there are highly pathogenic Lena strain outbreaks in eastern Europe. Why are these highly pathogenic PRRS outbreaks localized in some countries? Is there any possibility of these highly pathogenic PRRSV strains occurring in Korea? Can we not detect them in lab tests for some reason? Highly pathogenic PRRS (Porcine Reproductive and Respiratory Syndrome)  is characterized by unusual, very high morbidity in affected pigs compared to the traditionally known PRRS. A part from severe febrile reaction, a variety of gross lesions and clinical signs were reported from HP PRRS cases, but there is no single definitive clinical sign(s) and/or gross lesion(s) that are suggested as a conclusive diagnostic measure for HP PRRS. Sudden onset of very high mortality in suckling piglets (up to 100%), nursery pigs (up to 70%), finishers (up to 20%), and breeding sows (up to 10%) was an indicator for the HP PRRS in the Chinese pig herd in late 2000s and even higher mortality in the early 2010s. Because of this unique sudden occurrence of high mortality cases without involvement of any other pathogens, it is not easy for farmers and pig health related personnel to […]

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]]> https://prrscontrol.com/highly-pathogenic-prrs-strains/feed/ 0 Is the efficacy of piglet vaccination against other diseases related to immunosuppression by PRRS virus? https://prrscontrol.com/piglet-vaccination-immunosuppression-prrsv/ https://prrscontrol.com/piglet-vaccination-immunosuppression-prrsv/#respond Fri, 26 Mar 2021 10:38:06 +0000 https://www.prrscontrol.com/semen-quality-prrs-virus-vaccination-copy/ On a PRRS unstable farm, the efficacy of piglet vaccination against other diseases (Edema disease, PCV2 and M. hyo) was lower than expected. Was it related to immunosuppression by PRRS virus? There are a variety of factors responsible for the immune response to a given antigen in pigs. When pigs experience immunosuppression by any factor and/or factors, normal immune response can’t be elicited due to the lack of inflammatory cells and cytokine networking. There are several well-known pathogens that affect the pig immune system such as CSF, PCV2, and PRRSV. These viral pathogens attack either immune cells and/or lymphoid organs which leaves the affected pigs vulnerable to common pathogens and leads to a poor response to commercial vaccines.   Oedema disease vaccines, PCV2 or Mhyo vaccines as well as other vaccines do not work appropriately in pigs infected with these pathogenic agents. Serological surveillance indicated that the PRRSV infected farms showed very inconsistent antibody levels for various viral and bacterial antigens (Lyoo. Unpublished data) For PRRSV in particular, T cell immune response was transient and variable in PRRSV infected pigs (Murtaugh, 2004) and inflammatory cytokine (IL-10) level was much higher than in healthy animals (Ko et al 2016).     […]

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]]> https://prrscontrol.com/piglet-vaccination-immunosuppression-prrsv/feed/ 0 How long boars shed the virus in semen when infected with PRRSV? https://prrscontrol.com/infected-prrsv-semen-sows-insemintation/ https://prrscontrol.com/infected-prrsv-semen-sows-insemintation/#respond Thu, 31 Jan 2019 06:47:04 +0000 http://prrscontrolidiomas.advertis.es/prrs-serum-elisa-positive-pcr-negative-copy/ How long boars shed the virus in semen when infected with PRRSV? What is the clinical manifestation of the sows inseminated with semen from PRRS infected boars? Can we suspect PRRSV involvement when PCV2 vaccinated farms showed 20% early abortion around 25 days after artificial insemination (AI)?   Here is a detailed explanation to all the questions raised above regarding PRRSV transmission through semen and abortion rates:   Possible causes of 20% early abortions rate in sows Abortion in sows could be classified as follows: 1. Insemination (fertilization) to implantation stage (~14days). 2. During implantation stage (14 – around 35days). 3. Fetal growth stage (35days~). Causes of abortion in sows are diverse including seasonal and environmental factors (such as high heat), toxin (mycotoxins), nutritional factors (vitamins) and infectious agents. Single or multiple factors can be involved in the abortion. We have to remember that environmental factors are common cause of early abortion in healthy sows. Bacterial diseases such as Brucellosis, Letospirosis and viral agents as porcine parvovirus (PPV), Japanese encephalitis virus, porcine circovirus 2/3, encephalomyocarditis virus (EMCV), pseudorabies and porcine reproductive and respiratory virus (PRRSV) are known to cause abortion in pregnant sows. Contamination of the semen extender (E. coli, […]

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]]> https://prrscontrol.com/infected-prrsv-semen-sows-insemintation/feed/ 0 Some piglets have high PRRS titers and other bacterial agents as H. parasuis seem to be present. What should be done? https://prrscontrol.com/some-piglets-have-high-prrs-titers-and-other-bacterial-agents-as-h-parasuis-seem-to-be-present-what-should-be-done/ https://prrscontrol.com/some-piglets-have-high-prrs-titers-and-other-bacterial-agents-as-h-parasuis-seem-to-be-present-what-should-be-done/#respond Wed, 20 Dec 2017 08:00:58 +0000 http://prrscontrol.advertis.es/2018/04/18/in-a-prrsv-free-farm-where-there-is-a-risk-of-infection-during-transport-what-would-be-the-minimum-quarantine-period-copy/ In a farrow to finish farm, weaned piglets are depressed with high mortality. 4 and 8 week-old piglets have high PRRS titers and other bacterial agents as H. parasuis seem to be present. What measures should be taken? It’s very common phenomena in a PRRSV affected farrow to finish farms elsewhere. H. parasuis would be the opportunistic secondary infection due to the immune suppression by the PRRSV and/or PCV. Differential diagnosis is recommended between Type I (European) and/or Type II (North American) and preferred to have PCV2 diagnosis as well. Based on the test results, stabilization of the sow group using proper type of the modified live vaccine (PRRSV) would be the best choice to reduce the number of weak and poor doing piglets. If PCVAD has been diagnosed simultaneously, piglets need to be vaccinated with a commercial PCV vaccine. Once sows are stabilized by vaccination then the performance of the weaners will be gradually recovered. Poor doing piglets need to be moved to a hospital pen and get antibiotics to which the pathogen is sensitive. If possible herd closure is also recommended until problems are diminished. You can ask your own question! Visit Pig333.com and submit your question to […]

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]]> https://prrscontrol.com/some-piglets-have-high-prrs-titers-and-other-bacterial-agents-as-h-parasuis-seem-to-be-present-what-should-be-done/feed/ 0 What is the origin of PRRS virus and in what environment was the disease first developed? https://prrscontrol.com/what-is-the-origin-of-prrs-virus-and-in-what-environment-was-the-disease-first-developed/ https://prrscontrol.com/what-is-the-origin-of-prrs-virus-and-in-what-environment-was-the-disease-first-developed/#respond Wed, 18 Oct 2017 08:00:10 +0000 http://prrscontrol.advertis.es/2018/04/18/in-a-positive-inestable-farm-that-has-recently-used-two-different-prrs-us-mlv-vaccines-what-will-be-the-potential-risk-of-the-vaccine-to-revert-to-virulence-and-the-impact-on-sow-immunity-copy/ The PRRSV was transmitted from another host to swine in about 1980. There is no direct evidence of the origin of the PRRSV but after careful analysis of the genes and genome of the virus the closest virus species to PRRSV was LDEV in rodent. The first case of PRRSV known as ‘mystery swine disease or blue ear disease’ was reported in North America in the mid-1980s, and similar symptoms spread to other continents (Asia and Europe) by 1991. In 1991, two strains of PRRSV were first isolated independently in the United States and the Netherlands. Based on the research data the PRRSV diverged in approximately 1980.Field reports also strongly supported the estimated divergence times were 1972–1988. However, no data could identify with confidence that the two major types of PRRSV diverged simultaneously as PRRSV appeared in the United States and European continent. Because of the clinical manifestation and etiological identification did not coincide each other it’s difficult to determine the conditions of the first outbreak. The disease was diagnosed in numerous farms with a variety of management conditions with various age groups of the pigs. Two main clinical symptoms were reproductive failure in sow and respiratory disease in all […]

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]]> https://prrscontrol.com/what-is-the-origin-of-prrs-virus-and-in-what-environment-was-the-disease-first-developed/feed/ 0 In a positive inestable farm that has recently used two different PRRS US MLV vaccines what will be the potential risk of the vaccine to revert to virulence and the impact on sow immunity? https://prrscontrol.com/in-a-positive-inestable-farm-that-has-recently-used-two-different-prrs-us-mlv-vaccines-what-will-be-the-potential-risk-of-the-vaccine-to-revert-to-virulence-and-the-impact-on-sow-immunity/ https://prrscontrol.com/in-a-positive-inestable-farm-that-has-recently-used-two-different-prrs-us-mlv-vaccines-what-will-be-the-potential-risk-of-the-vaccine-to-revert-to-virulence-and-the-impact-on-sow-immunity/#respond Mon, 04 Sep 2017 08:00:28 +0000 http://prrscontrol.advertis.es/2018/04/18/prrs-vaccination-in-suckling-piglets-could-it-be-interfered-by-maternal-derived-antibodies-copy/ After using an US type MLV vaccine for 3 years there was a PRRS outbreak (US strain) last year. Now a new US MLV vaccine is being used for piglets, sows were mass vaccinated once. After using the new PRRS vaccine for 4 months, we still find PCR-positive piglets and clear clinical signs 4 weeks after injection (20-40% loss rate in the nursery unit). What will be the potential risk/concern of reverting to the original US PRRS vaccine? Having used 2 US MLV vaccines during last year, what will be the impact on sow immunity following a quarterly basis mass vaccination? The purpose of the PRRSV vaccination in positive herds is eradication and/or stabilization of the PRRS more effectively. Simultaneous application of PRRSV vaccination and herd closure works very well in most of the cases. An important point prior to vaccination is determining the type of the virus (NA or EU, NA and EU) circulating in the affected farms. Choosing homologous type of the vaccine is very critical to control the disease. Samples need to be send for genetic analysis. If the detected virus is vaccine virus then I do recommend stopping the NEW US MLV administration. I also recommend […]

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]]> https://prrscontrol.com/in-a-positive-inestable-farm-that-has-recently-used-two-different-prrs-us-mlv-vaccines-what-will-be-the-potential-risk-of-the-vaccine-to-revert-to-virulence-and-the-impact-on-sow-immunity/feed/ 0 PRRS vaccination in suckling piglets: could it be interfered by maternal-derived antibodies? https://prrscontrol.com/prrs-vaccination-in-suckling-piglets-could-it-be-interfered-by-maternal-derived-antibodies/ https://prrscontrol.com/prrs-vaccination-in-suckling-piglets-could-it-be-interfered-by-maternal-derived-antibodies/#respond Thu, 22 Jun 2017 12:08:00 +0000 http://prrscontrol.advertis.es/2018/04/17/are-elisa-results-meaningful-to-understand-the-efficacy-of-a-prrs-vaccine-copy/ When suckling piglets are vaccinated with PRRS MLV, could it be interfered by maternal-derived antibodies? If so, should vaccination be delayed until weaning period or even later? Vaccination in suckling animals are always challenging because of maternally derived antibodies which interferes specific immune response in vaccinated animals. PRRSV vaccine is not an exception and vaccination schedule needs to be adjusted based on the level of the colostrum antibody specific to PRRSV. For piglets delivered from PRRSV vaccinated sows, vaccination schedule needs to be delayed after weaning. Evaluation of PRRSV specific antibody levels in piglets are essential to determine the proper vaccination schedule. Since continuous sow vaccination elicit more uniform antibody levels than natural infection by the field strains, therefore it is much easier to adjust vaccination schedule. You can ask your own question! Visit Pig333.com and submit your question to our experts. Young LyooUniversity of Konkuk, South Korea

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]]> https://prrscontrol.com/prrs-vaccination-in-suckling-piglets-could-it-be-interfered-by-maternal-derived-antibodies/feed/ 0 Are ELISA results meaningful to understand the efficacy of a PRRS vaccine? https://prrscontrol.com/are-elisa-results-meaningful-to-understand-the-efficacy-of-a-prrs-vaccine/ https://prrscontrol.com/are-elisa-results-meaningful-to-understand-the-efficacy-of-a-prrs-vaccine/#respond Sun, 11 Jun 2017 08:00:28 +0000 http://prrscontrol.advertis.es/2018/04/17/what-do-you-think-about-prrs-and-aujeszkys-combined-vaccines-in-pregnant-sows-copy/ Some farms where NA type MLV had been used for a long time, decided to change their vaccine to EU type MLV. After 1- 2 month since they started EU type MLV, they did antibody monitoring by using ELISA. Through this sero-monitoring, we can see the negative or variable level of antibody titer in the whole pig group. Are these ELISA results meaningful to understand vaccine efficacy in each farm? Administration of the PRRSV vaccine in pigs will induce specific antibodies to corresponding viral proteins. Those antibodies can be detected by several serological tests. ELISA is one of the most common test to detect the PRRSV antibodies. Vaccination will increase the rate of antibody positive and its titer in vaccinated pigs but repetitive vaccination will not increase further the antibody titer. Several ELISA kits are available for the PRRSV antibody detection and results are variable depending on the commercial kits. Animals vaccinated with PRRSV usually show seroconversion by 21 days post vaccination by ELISA test. Some of the specific kits are developed for the type 1 PRRS virus. IDEXX PRRS X3 Ab Test will detect antibodies to type 1 PRRSV, based on the manufacturer’s test result release. Animals vaccinated with […]

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