BACKGROUND:Ileitis is a wasting disease of pigs. Clinical symptoms are diarrhea in growing pigs, wasting and reduced performance. Ileitis is ubiquitous in pig producing countries all around the world. It is estimated that the economic losses caused by the disease are USD 4.65 per fattening pig, and American pig farmers lose USD 56.1 million annually. It has become necessary to develop a slaughterhouse ileitis monitoring method that is simple, feasible to perform at modern slaughter lines, leads to immediate results and is cost effective. The practical experiences of applying the method are presented below.METHODS:Our studies were performed on pig herds and slaughterhouses in Central European countries (Hungary, Romania, Poland, Croatia, and Slovakia). Experiences were evaluated based on visual and palpation. The results of our investigations were evaluated by a scoring method. Authors made histological and immunohistochemical examinations of investigated ileums. The hypothetic economic losses due to the disease in each farm were determined by estimating the loss of profit according to Holtkamp's presentation in 2019.RESULTS:The essentials of the method we have developed are: it can be performed during slaughterhouse processing, it does not interfere with or make it impossible to carry out normal technological processes, and the results of the procedure are correlated with the results of other laboratory diagnostic tests for ileitis (histology, immunohistochemistry, herd serology, fecal PCR). It is noteworthy that the results of the method can be used to immediately estimate the impact of Lawsonia intracellularis infection on the performance of the herd from which the slaughter animals come.CONCLUSION:Using the results of the slaughtered pigs' visual and tactile examination at the slaughterhouse, the magnitude of the loss caused by Lawsonia intracellularis infection can be estimated quickly and accurately, and the return on investment of the strategy to be applied can be accurately planned.

A szerzők közleményükben bemutatják egyes szaporodásbiológiai mutatók alakulását a PRRS-fertőződés és a mentesítés fázisaiban. A nagylétszámú, fialástól a vágásig típusú, PRRS-fertőzött állományok mentesítése során a tenyészállomány vakcinázását negyedévente végezték. Az utódállományban az immunizálás eredményességét laboratóriumi vizsgálatokkal ellenőrizték, és pontosan meghatározták annak megszüntethetősége időpontját. Ugyanakkor a belső járványvédelem alkalmazott módszereit szükség szerint felülvizsgálták. Ennek eredményeképpen a telep teljesítette a mentes, vakcinázott sertéstelepre vonatkozó hatósági követelményeket.

Porcine reproductive and respiratory syndrome (PRRS) is a widespread infectious disease that is currently a major cause of economic losses in pig production. In Hungary, a National PRRS Eradication Program has been introduced to attain a more efficient, economic, and competitive international market position. The program has been also approved by the EU, but the resulting legal obligations have imposed a burden on Hungarian producers to comply with EU competition rules. The implementation of the program has been carried out by the veterinary authorities with the consent of, continuous support from and monitoring conducted by organisations within the pig sector as well as a scientific committee. The PRRS eradication program in Hungary was based on a regional territorial principle and was compulsory for all pig holdings within the regions. In Hungary, large fattening farms operate as all-in/all-out or continuous flow systems. Large-scale breeding herds are predominantly farrow-to-finish types. Although its significance has decreased in recent decades, 20% of the Hungarian pig population is still kept on small (backyard) farms (<100 animals). All PRRSV-infected large-scale farms had to develop a unit-adapted eradication plan, including external and internal biosecurity measures, vaccinations, etc. It was crucial to render each fattening unit free of the disease, as fattening units play a significant role in spreading the virus within the country. The eradication efforts mainly implemented were depopulation-repopulation methods, but on some farms a testing and removal method has been used. As the eradication progressed over the years, the introduction of infected fattening pigs was restricted. Thanks to these measures, Hungarian large-scale fattening farms became PRRSV-free by the end of 2018. The PRRSV-free status of small-scale herds was achieved by the end of 2015 and was maintained between 2016 and 2021. By 31 December 2021, all breeding pigs in large-scale farms in Hungary were free of wild-type PRRS virus. By 31 March 2022, the total pig population of the country, including all backyard farms and fattening units, achieved PRRSV-free status. The future goal is to ensure and maintain the PRRSV-free status of Hungary via strict import regulations of live animals combined with the continuous and thorough screening of incoming and resident herds for the presence of the virus.

Background: One of the biggest challenges in the eradication of PRRS in Hungary's pig herds was the eradication from large-scale farrow to finish farms. Among the methods used for this purpose, the depopulation-repopulation is obviously the safest, but also the most expensive procedure. Objectives: Specialists have continuously strived to develop a method and to apply it under Hungarian conditions, which enables the immunization of the breeding stock, but ensures virus -free rearing for the entire life stage of the offspring. Since 2017, the international regulations of PRRS have provided the opportunity for this. Materials and Methods: Studies were carried out on a pig farm with 850 sows, from farrowing to slaughter, located in the county with the highest density of pigs in Hungary and the one most infected with PRRS in 2014. The farm was infected with the disease until 2016, and then in 2016-17, with a complete depop-repop with high animal health status was put nto production. At the beginning of 2018, the farm was infected with a strain of the PRRS virus that did not occur in the previous herd. During the eradication of this herd, the mass vaccination of the breeding stock was carried out quarterly. The effectiveness of the vaccination in the progeny was checked with laboratory tests (PRRS ELISA, PRRS PCR DIVA), and with these tests the time when the immunization of the progeny could be stopped was precisely determined. At the same time, the methods of internal epidemic prevention were regularly revsed. Results and Discussion: In 2021, the farm met the official requirements of a free, vaccinated pig farm from farrowing to slaughter, for which it received a certificate. The authors present the evolution of some reproductive biological indicators (stillbirths and live births per farrowing) during the phases of infection and eradication.

Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV) causes severe economic losses worldwide and only four countries in Europe are free from PRRSV. Complete depopulation–repopulation is the safest and fastest, but also the most expensive method for eradicating PRRSV from a population. Another possible way to eliminate an endemic PRRSV infection is to replace the infected breeding stock by gilts reared isolated and protected from PRRSV on an infected farm. With this method it is possible to maintain continuous production on the farm. The authors report the first successful elimination of PRRSV in a Hungarian large-scale pig farm by using an inactivated vaccine and performing segregated rearing of the offspring. Case presentation The study was performed on a PRRSV infected farm (Farm A) with 1475 sows. The clinical signs of reproductive failure had been eliminated previously by using an inactivated vaccine (Progressis®, Ceva). At the beginning of the elimination programme, gilts intended for breeding were vaccinated at 60 and 90–100 days of age. After that, gilts selected for breeding were vaccinated at 6 months of age, on the 60–70th day of pregnancy and at weaning. Approximately 1200 piglets from vaccinated sows were transported at 7 weeks of age to a closed, empty farm (Farm B) after being tested negative for PRRSV by a polymerase chain reaction (PCR) method, and then were reared here until 14 weeks of age. At this age, all pigs were tested by PRRS ELISA. Seronegative gilts (n = 901) were subsequently transported from Farm B to a third, closed and empty farm (Farm C), and (having reached the breeding age) they were inseminated here after a second negative serological test (ELISA). At the same time, Farm A was depopulated, cleaned and disinfected. All pregnant gilts were transported from Farm C to Farm A after being re-tested negative for antibodies against PRRSV. Follow-up serology tests were performed after farrowing and results yielded only seronegative animals. Based on the subsequent negative test results, the herd was declared PRRSV free by the competent authority. Conclusions The presented farm was the first during the National PRRS Eradication Programme of Hungary to eradicate PRRSV successfully by vaccinating the sows with an inactivated vaccine and performing segregated rearing of the offspring. Production was almost continuous during the whole process of population replacement.

Background: There are no uniform housing technology, feeding, disease control, preventive or therapeutic treatment protocols in the large-scale pig breeding farms in Hungary. Most of the large-scale, industrialised and specialised swine units had been built in the 1970s, according to the technological level typical of that period. Since then, the costs spent on their renovation or full reconstruction were much less than would have been necessary. Porcine reproductive and respiratory syndrome (PRRS) causes significant losses in the swine industry worldwide, which leads to launching eradication programmes. The PRRS eradication programme in Hungary is based on the territorial principle, and it is obl gatory for each swine farm irrespective of the number of animals kept there. Objectives: Hungary has exceptionally large herd size in large-scale pig farms. The large-scale breeding herds are predominantly farrow-to-finish types. Following the successful implementation of the Aujeszky's disease eradication programme, elimination of PRRSV from each pig in Hungary would greatly facilitate the growth of market opportunities. Materials and Methods: In large-scale breeding farms, PRRS eradication was carried out by the depopulation-repopulation method in 33 farms, of which 23 received state compensation, 18 farm units either finished production, or changed to producing fatteners only. Two farms used the test and removal method for eradication. One farm was classified as 'vaccinated free'. At this farm the breeding animals are vaccinated continuously but there is no vaccination of the progeny at any age, and the PRRS-free status of the farm is strictly controlled and monitored. Results and Discussion: By 31 December 2019, all pigs in five Euroregions of Hungary became free from PRRS virus, while the PRRS eradication process is still ongoing in the remaining two regions.

Background: Eradication of porcine reproductive and respiratory syndrome virus (PRRSV) from the pig population of Hungary started in 2014 on territorial basis. Objectives: Since fattening units play a significant role in spreading the virus all over the country, it was of high importance to render each fattening unit free from PRRS. In 2015, 188 out of 307 large-scale fattening farms (61.2%) kept PRRS-positive animals. The major source of infection of these farms was the import of PRRSV positive fattening pigs. Materials and Methods: The following methods were used during the eradication from 2017: (1) Only pigs originating from PRRS free farms were allowed to be used for fattening in Hungary; (2) Quarantine of all herds for 60 days; (3) PCR test for PRRSV 48 hours after the arrival of the prefattening animals; (4) Serological test for PRRSV at the end of the quarantine period. If any of diagnostic tests gave even one positive result and the result was confirmed by additional tests, the stock had to be sold for slaughter within 15 days or allocated outside Hungary. PRRSV eradication on large-scale fattening units operating all-in/all-out system was relatively simple, using the depopulation-repopulation method. In contrast, on continuously operating farms, the infected herd was sold from time to time, without having to be repopulated until the last delivery. After cleaning, disinfection and restocking, the repopulation was performed with PRRS-free animals. Results and Discussion: As a consequence of the above measures, by the end of 2018, all Hungarian large-scale fattening farms became free of PRRS. Maintaining the national -level PRRS-free status of large-scale pig fattening units contributes to eliminating a significant cost factor from the Hungarian pork production industry, and opens the way for a significant reduction in antibiotic use as well.

The prevalence of PRRS infections is high in countries keeping significant amount of swine all over the world. Therefore, the Pig Strategy of the Government of Hungary decided to eradicate of PRRSV in Hungary. For the first time among the EU Member States, a National PRRS Eradication Programme was introduced in order to reach a more efficient, economical and competitive international market position. Even nowadays, 20% of the Hungarian pig population is still kept on small-scale (backyard) farms (< 100 animals). The prevalence of PRRSV in backyard farms was 3.9% at the beginning of the programme. The present paper details the steps applied during eradication in backyard farms. During all the phases, serological testing of the breeding animals of the registered small-scale herds was performed, seropositive individuals were tested by PCR and were removed from the backyard farm within the framework of official measures. By sequencing the identified PRRS strains, the possible epidemic relationships between small-scale and large-scale farms were continuously monitored. As a result of the programme, PRRS-free status of the small-scale herds was achieved by the end of 2015, and this status was maintained in 2016-2019.

Porcine reproductive and respiratory syndrome (PRRS) is a globally spread, highly infectious viral disease. Live, attenuated vaccines against PRRS virus (PRRSV) decrease virus excretion and evoke protective immunity reducing the economic damage caused by the disease. In a longitudinal molecular epidemiological study accompanying ongoing national eradication programme we evaluated the suitability of PRRSV ORF5 and ORF7 sequences to identify possible field strains of vaccine-origin. In total, 2342 ORF5 sequences and 478 ORF7 sequences were analysed. Vaccine strains were identified by sequence identity values and phylogenetic network analysis. Strains that shared greater than 98% nucleotide identity within ORF5 and/or ORF7 were considered to have originated from vaccine. A total of 882 (37.6%) ORF5 and 88 (18.4%) ORF7 sequences met these criteria. In detail, 618, 179 and 35 ORF5 and 51, 29 and 8 ORF7 sequences were related to Porcilis PRRS vaccine, Unistrain PRRS vaccine, and ReproCyc PRRS EU vaccine, respectively. Data showed that the Porcilis vaccine was genetically more stable. Whereas, the variability of the Unistrain and the ReproCyc strains was significantly higher. Given that ORF7 shares, in some instances, complete identity between a particular vaccine strain and some historic variants of field PRRSV strains, care must be taken when evaluating vaccine relatedness of a field isolate based on the ORF7. On the contrary, ORF5 sequences were more suitable to predict the vaccine origin making a distinction more robustly between field and vaccine strains. We conclude that ORF5 based molecular epidemiological studies support more efficiently the ongoing PRRS eradication programmes. The conclusions presented in this large-scale PRRS molecular epidemiological study provides a framework for future eradication programmes planned in other countries.

Porcine reproductive and respiratory syndrome (PRRS) causes significant losses to the swine industry worldwide, which leads to launching eradication programmes. The PRRS eradication programme in Hungary is based on the territorial principle, and it is obligatory for each swine farm irrespective of the number of animals kept there. Hungary has an exceptionally large herd size in large-scale pig farms. Large fattening farms operate as all-in/all-out or continuous flow systems. The large-scale breeding herds are predominantly farrow-to-finish types. In large-scale breeding farms, PRRS eradication was carried out by the depopulation-repopulation method in 33 farms, of which 23 received state compensation, 18 farm units either finished production or changed to producing fatteners only. Two farms used the test and removal method for eradication. One farm was classified as 'vaccinated free'. At this farm the breeding animals are vaccinated continuously but there is no vaccination of the progeny at any age, and the PRRS-free status of the farm is strictly controlled and monitored. By 31 December 2019, all pigs in five euroregions of Hungary had become free from PRRS virus, while the PRRS eradication process is still ongoing in the remaining two regions.

In Hungary, the economic losses caused by porcine reproductive and respiratory syndrome virus (PRRSV) led to the launching of a national PRRSV Eradication Program. An important element of the program was investigating the spread of PRRSV among swine herds and the possible ways of introduction by sequencing of the open reading frame 5 (ORF5) gene. However, the classical phylogenetic tree presentation cannot explain several genetic relationships clearly, while more precise visualization can be represented by network tree diagram. In this paper, we describe a practical and easy-to-follow enriched minimum spanning similarity network application for improved representation of phylogenetic relations among viral strains. This method eliminated the necessity of applying a predefined, arbitrary cut-off or computationally extensive algorithms. The network-based visualization allowed processing and visualizing large amount of data equally for the laboratory, private and official veterinarians, and helped identify the potential connections between different viral sequences that support data-driven decisions in the eradication program. By applying network analysis, previously unknown epidemiological connections between infected herds were identified, and virus spreading was analyzed within short period of time. In our study, we successfully built and applied network analysis tools in the course of the Hungarian PRRSV Eradication Program.

Eradication of porcine reproductive and respiratory syndrome virus (PRRSV) from the pig population of Hungary started in 2014 on the basis of the territorial principle. In order to reach this goal it was crucial to render each fattening unit free of this disease, since fattening units play a significant role in spreading the virus all over the country. In 2015, 188 out of 307 large-scale fattening farms (61.2%) kept PRRS-positive animals. The main source of infection of these farms was the import of PRRS-infected fattening pigs. The following methods were used during the eradication from 2017: (1) Only pigs coming from PRRS-free farms were allowed to be used for fattening in Hungary; (2) Quarantine of all herds for 60 days; (3) PCR test for PRRS 48 hours after the arrival of the prefattening animals; (4) Serological test for PRRS at the end of the quarantine period. If any diagnostic test gave even one positive result and the result was confirmed by another test, the stock had to be sold for slaughter within 15 days or placed outside Hungary, so that the infected stock would not compromise the PRRS status of that area. PRRSV eradication on large-scale fattening units applying all-in/all-out operation was relatively simple, using the depopulation-repopulation method. On permanently operating farms, the infected herd was sold from time to time, without having to be repopulated until the last delivery. After cleaning, disinfection and restocking, the repopulation was done with PRRS-free animals. As the eradication progressed over the years, a ban on the import of infected fattening pigs was imposed. As a consequence of these measures, by the end of 2018, Hungarian large-scale fattening farms became free of PRRS. Maintaining the national-level PRRS-free status of large-scale pig fattening units contributes to eliminating a significant cost factor from the Hungarian pork production industry, and opens the way for a significant reduction in antibiotic consumption as well.

In the EU Member States with a traditionally significant pig industry, the prevalence of PRRS infections is high. Therefore, the Pig Strategy of the Government of Hungary prioritises eradication of PRRSV in Hungary. For the first time among the EU Member States, a National PRRS Eradication Programme was introduced in order to reach a more efficient, economical and competitive international market position. Although its significance has decreased in recent decades, 20% of the Hungarian pig population is still kept on small-scale (backyard) farms (< 100 animals). The prevalence of PRRSV in backyard farms was 3.9% at the beginning of the programme. The present paper details the measures applied during the different phases of the programme in backyard farms. During all the phases, serological testing of the breeding animals of the registered small-scale herds was performed, including the highest number of individual animals. Seropositive individuals were tested by PCR and were removed from the backyard farm within the framework of official measures. By sequencing the identified PRRS strains, the possible epidemic relationships between small-scale and large-scale farms were continuously monitored. As a result of the programme, PRRS-free status of the small-scale herds was achieved by the end of 2015, and this status was maintained in 2016-2018.

The fusariotoxin contamination of the feeds poses a major risk to the very susceptible swine and poultry. In the second part of the paper the authors survey the cause, clinicopathology, differential diagnosis and control of swine and poultry fusariotoxicoses.