Piglet coccidiosis caused by Cystoisospora suis is one of the most important causes of diarrhea in suckling piglets. The parasite has a fast development and multiplies quickly and effectively under the conditions of a farrowing unit. Control measures include cleaning and disinfection and anticoccidial treatment. In Europe, toltrazuril-based products are authorized for this purpose and are applied to piglets on affected farms in the first week of life. To observe the effect of treatment and disinfection on the control of piglet coccidiosis in the field, 23 farms (11 from Belgium, 12 from the Netherlands, mean number of sows = 1413) were sampled twice by litter in the second and third week of life and fecal scores and the presence of C. suis oocysts were determined. A questionnaire was used to collect data on farm sizes, management and hygiene measures as well as treatment (product, dose and piglet age). Thirteen farms regularly treated with toltrazuril (treatment age: 1-6 days, mean 4.3 days) and 19 applied disinfection. Parasite excretion was documented on 60.9% and diarrhea on 78.3% of farms and in 34.3%/15.7% of the litters. Only 2.4% of the litters showed both, so subclinical infection appeared to be common. No significant differences between farms that did not treat against coccidiosis and farms that applied toltrazuril was observed with regard to C. suis oocysts shedding and/or diarrhea. However, in litters that were treated within the first three days of life, oocyst excretion was significantly less often observed than in litters with later treatment (p = 0.033). No significant effect of disinfection could be shown, but most farms applied disinfectants that have no proven effect against coccidia (oxygen-releasing agents or glutaraldehyde + ammonia) while the only farm that used chlorocresols (which are effective against coccidia) did not show oocyst shedding. Current control measures thus appear to be insufficient on most of the examined farms. It is therefore recommended to treat piglets timely and to apply effective disinfectants to reduce C. suis infections. Furthermore, regular evaluation of sustained efficacy of all implemented measures are necessary.

BACKGROUND:Salmonella Typhimurium is an important zoonotic pathogen in pigs, that can cause clinical disease. Many sow herds and finishing herds are infected with Salmonella, and therefore pose a threat for the contamination of pork and pork products and ultimately consumers.CASE PRESENTATION:This case study describes a farrow-to-finish pig herd, producing its own replacement gilts, which had experienced clinical outbreaks of salmonellosis since 2002. Outbreaks were characterised by profuse diarrhoea, dead pigs and high antimicrobial use (colistin sulphate). The aim of this study was to see whether using vaccination of sows and piglets with Salmoporc®, a live attenuated Salmonella Typhimurium vaccine, in combination with standard hygienic precautions, it was possible to reduce Salmonella Typhimurium to below the bacteriological detection limit. Monitoring of the presence of Salmonella was done using a total of 20 pooled faecal, sock and dust samples per herd visit in the period from September 2016 to October 2020. Within the first 10 months after the start of vaccination in August 2016, there was a rapid reduction in clinical symptoms, antimicrobial usage and the number of Salmonella-positive samples. During the winters of 2017/2018 and 2018/2019 the number of positive samples increased again, however with minimal need to use antimicrobials to treat the affected animals. In July 2019, only two samples from a corridor were positive. In September and November 2019 and in October 2020 all three samplings were completely negative for S. Typhimurium.CONCLUSIONS:This case, together with other longitudinal studies, can be seen as a proof of the principle that long term vaccination with a live attenuated S. Typhimurium vaccine can reduce the level of S. Typhimurium in the herd environment to very low levels within a farrow-to-finish herd initially suffering from clinical salmonellosis. Also, clinical symptoms indicating salmonellosis were no longer observed and antimicrobials to treat clinically diseased pigs were no longer needed.

Porcine epidemic diarrhea virus (PEDV) is the highly contagious, causative agent of an economically important acute enteric disease in pigs of all ages. The disease is characterized by diarrhea and dehydration causing mortality and growth retardation. In the last few decades, only classical PEDV was reported sporadically in Europe, but in 2014 outbreaks of PEDV were described in Germany. Phylogenetic analysis showed a very high nucleotide similarity with a variant of PEDV that was isolated in the US in January 2014. The epidemiological situation of PEDV infections in the Netherlands in 2014 was unknown and a seroprevalence study in swine was performed. In total, 838 blood samples from sows from 267 farms and 101 samples from wild boars were collected from May till November 2014 and tested for antibodies against PEDV by ELISA. The apparent herd prevalence of 0.75% suggests that PEDV was not circulating on a large scale in the Netherlands at this time. However, in November 2014 a clinical outbreak of PEDV was diagnosed in a fattener farm by PCR testing. This was the first confirmed PEDV outbreak since the early nineties. Sequence analyses showed that the viruses isolated in 2014 and 2015 in the Netherlands cluster with recently found European G1b strains. This suggests a one event introduction of PEDV G1b strains in Europe in 2014, which made the Netherlands and other European countries endemic for this type of strains since then.

The aim of this study was to develop a Typhimurium (ST) challenge model in weaned pigs suitable to evaluate effects of water and feed interventions on fecal shedding and growth performance. Two studies were performed. In Exp. 1 weaned pigs were fed either a standard diet (CON) or a diet with a high buffer capacity (HB) and challenged for either 3 or 7 consecutive days in a Latin square design with 4 × 8 individually housed pigs. In Exp. 2, the CON 7-d challenge method was chosen for further model development and validation. Thirty-two individually housed weaned pigs were divided over 4 treatments: a nonchallenged control group (NCON), a challenged positive control group (PCON), a challenged intervention group with acidified water (WATER), and a challenged intervention group with acidified feed (FEED). Pigs were orally challenged once daily on d 7 to 9 or d 7 to 13 after weaning (d 0) with 1 ×10 cfu ST. From d 0 to 28, rectal temperature and occurrence of diarrhea were recorded daily, and BW and feed intake were measured weekly. Fecal samples were collected on d 0, 2, 7, 9, 13, 16, 20, 23, and 27 in Exp. 1 and d 0, 2, 7, 8, 9, 13, 15, and 27 in Exp. 2 for quantification. The results of both experiments showed quantifiable fecal shedding (average peak shedding of approximately 3.5 log and 5.5 log cfu/g, respectively), accompanied by a transient 0.5°C increase in rectal temperature and an increase in occurrence of diarrhea. In Exp. 2 during the week of challenge (i.e., d 7 to 14), a reduction in growth performance (ADG: -157 to 200 g/d and G:F: -0.22 to 0.25 g/d; < 0.01) in PCON and FEED was observed compared to NCON, with WATER showing an intermediate response. The WATER treatment also showed a numerically lower peak shedding (difference of -1.3 to 1.4 log cfu/g) compared to PCON and FEED. To conclude, we repeatedly infected weaned pigs successfully with 1 × 10 cfu of ST for 7 consecutive days, resulting in detectable and quantifiable fecal shedding. This ST challenge model may be suitable for evaluation of effects of water and feed interventions on peak fecal shedding and growth performance.

ORAL PRESENTATIONS test results. In other words, although single sera, which have Salmonella antibody concentrations around the cut-off point, can be recognized as positive with one test and negative with the other test or vice versa, the three tests can be used, since less than 10% of the sera tested over years in Germany, have Salmonella antibody concentrations around the cut-off point (around 70% have very low titers, and about 15% have quite high titers, which are always correctly identified by all three tests as negative or positive). This means that the risk that a set of sera is categorized differently by using another test out of the three tests is so low that it can be neglected in the light of the overall goal of the German Salmonella Monitoring and Reduction Programme: Identifying via an ongoing semiquantitative estimation the herds with the relatively highest risk of introducing zoonotic Salmonella spec. into the food production chain to be able to implement measures for a) reducing the crosscontamination of Salmonella spec. in the slaughter plant and b) reducing the salmonella load of swine herds identified as high risk herds. Finding the herds with the relatively highest salmonella risk, at which cut-off point ever, will be performed by all three tests at a comparative herd sensitivity level.

Aim of this study was to determine if a known MRSA contamination within a pig herd could persist for a period of two years.Material and Methods: 16 pig herds with a known MRSA contamination were asked to participate in this study.Per herd, five dust swabs (Sodibox®) were collected every two months for a period of two years.Samples were tested for presence of MRSA by culture and two PCR's for confirmation of MRSA.Isolates were typed by spa-en MLVA-typing.Results: These 16 herds were sampled 177 times, varying from 4 to 13 times per herd.72.9% of all samplings had at least one positive sample.Per herd this ranged from 38% to 100%.A total of 882 dust swabs were collected, of which 32.8% were positive, varying from 12% to 58% per herd.284 isolates were spa-typed, yielding 17 different spatypes, mostly t011 and t108, with a minimum of 1 and a maximum of 6 spa-types per herd for the entire period and with a maximum of 3 per sampling.MLVA-typing did not lead to much more information, only in one herd there were two different types of spa-type t011: t011-398 (common) and t011-555 (only once).In 12 herds there was a spa-type which was found from beginning to the end of the test period.In 4 herds the same spa-type was found, and still prominent, as was found in the initial sampling in 2008.In many herds there were incidental findings of rare spa-types.Detailed results can be found in table 1. Conclusions:Overall a dynamic picture of contamination emerges, with herds being contaminated with a single type for a long time, dominant spa-types being replaced by another type and occasional findings of rare types.Both within herd reduction of contamination and prevention of new introductions will be necessary to control MRSA in pig herds.

There are many reports on the occurrence of Livestock Associated Methicilline resistant Staphylococcus aureus (LA-MRSA, CC398) in healthy pigs. There are however, very few reports of LA-MRSA being associated with pathological lesions in pigs. With this study we try to find the answers to the questions: (1) how often is S. aureus found in post-mortem material from pigs, (2) how many of these isolates are methicillin resistant, (3) are these equally distributed over the years? Here we report the isolation of MRSA and of methicillin sensitive S. aureus (MSSA) from samples derived from post-mortem examinations at the Animal Health Service in The Netherlands in the period from 2003 through October 2008. The MSSA and MRSA described here were isolated from 159 pathological lesions and from 7 submissions of aborted foetuses derived from a total of 116 animals, representing 103 submissions coming from 92 different herds. This is approximately 0.5% of all pigs submitted for post mortem examination in those years. The proportion of pigs from which S. aureus (both MSSA and MRSA) was isolated from, did not increase over the years. MSSA (N = 97) and LA-MRSA CC398 (N = 18) were present mainly in (peri)arthritis in over 30% of all cases, but were also isolated from internal organs such as lung, brain, spleen, kidneys, heart, indicating septicaemia. Remarkably, one non-CC398 MRSA (ST1) was isolated in a joint and a kidney of one pig. This isolate was resistant to 5 out of 6 antimicrobials tested. There was no significant difference in the type of lesions in which LA-MRSA was found compared to MSSA. The number of antimicrobials these isolates were resistant to, increased rapidly after 2004. LA-MRSA was isolated for the first time in 2005 and then again in 2007 and 2008, suggesting that this is an emerging pathogen. However, due to changes in the panel of antimicrobials used to test S. aureus for antimicrobial susceptibility in 2005 and 2007, the possibility exists that we may have missed some MRSA isolates. LA-MRSA isolates are resistant to at least three but sometimes five out of six antimicrobials tested. All isolates were susceptible to the combination of Trimethoprim/Sulfamethaxol.

Since the detection of MRSA CC398 in pigs in 2004, it has emerged in livestock worldwide. MRSA CC398 has been found in people in contact with livestock and thus has become a public health issue. Data from a large-scale longitudinal study in two Danish and four Dutch pig herds were used to quantify MRSA CC398 transmission rates within pig herds and to identify factors affecting transmission between pigs.

Monitoring systems are in place to categorize pig finishing herds, abattoirs and cutting plants for their level of Salmonella contamination.In order to improve their status, if necessary, the companies and their advisors need to implement an improvement plan.This can be based on a strengths and weaknesses analysis in relation to all factors that contribute to the Salmonella contamination level.To do this analysis in a uniform, structured and repeatable way, internet based checklists were developed.In the checklist for herds questions relating to the Salmonella status of introduced piglets, transport hygiene of piglets, housing, management, cleaning and disinfection, feeding, disease status, rodent and fly control, and unloading practices are listed.Standard operating procedures (SOP's) will be available on the website for references on, for example, cleaning and disinfection, rodent and fly control, sampling and testing of weaned piglets / growers as well as hygiene checks.In the checklist for abattoirs questions relating to transport, holding area, slaughter, chilling, cleaning, disinfection and hygiene are listed.For cutting plants questions relating to the quality of received goods, chilling, cutting, packaging, transport, hygiene, documentation, and cleaning and disinfection are listed.Expert opinion is and will be gathered to weigh the different chapters and sub-questions in the checklists.The final score allows comparison to previous checks and to peers.Scores per chapter allow a ranking of most urgent points to be remedied in order to improve the Salmonella status.The internet application allows access to the checklist from any location at any time; however, pdf-documents of blank or completed checklists can be printed when desired.Logins provide sufficient privacy protection.Storage of the data in a central database provides data security.The checklists will be available in German, Dutch and English.User feedback will be used to improve all aspects of this tool continuously.

To investigate the occurrence of Bartonella sp. infection in asymptomatic horses and donkeys living in Tuscany, Central Italy.Blood samples were collected from 77 horses and 15 donkeys and tested by indirect immunofluorescent test to detect antibodies against Bartonella sp. and by PCR to detect the pathogen.Fifty-four (58.69%; 95% CI: 47.95%–68.87%) animals, 9 donkeys and 45 horses, were seropositive with antibody titers ranging from 1:64 to 1:512. PCR assays detected 9 horses positive for Bartonella sp. and 3 donkeys for Bartonella henselae genotype I.The detected sero-prevalence suggests a common and frequent exposure of equids living in Central Italy to bartonellae and PCR results show that Bartonella sp. infection is possible both in horses and donkeys. At the best of our knowledge, this is the first report of Bartonella henselae infection in donkeys.

In 2005, a distinct clone of methicillin resistant Staphylococcus aureus (MRSA CC398) was found in pigs and people in contact with pigs. The structure of the pig production chain in high technology pig husbandry enables pathogens to spread during animal trading, with an increasing prevalence in herds further down the chain. The objective of this study was to quantify the effect of the MRSA status of the supplying herd on the MRSA status of the receiving herd in order to gain more insight into the role of animal trading as a transmission route for MRSA CC398. Nasal samples (60–80 pigs per herd) were collected from 38 herds; in 20 herds, environmental samples were collected as well. Ten MRSA-positive herds (based on the results of nasal swabs of 10 individual pigs per herd) from a prior study were included in the data analysis. Herds were classified as MRSA positive if at least one sample tested positive. The 48 herds were part of 14 complete (40 herds) and 4 incomplete (8 herds) pig production chains. Fifty-six percent of the herds were classified as MRSA positive. MRSA-positive herds were observed at the start (breeding herds), middle (farrowing herds) and the end (finishing herds) of the pig production chain. All of the herds in 8 chains tested MRSA positive;, all of the herds in 5 chains tested MRSA negative and in the remaining 5 chains, MRSA-positive and MRSA-negative herds were detected. Seven spa types were found, which were all previously confirmed to belong to CC398. All of the isolates were susceptible to mupirocin, linezolid, rifampicin, fusidic acid and cotrimoxazole. Resistance against tetracycline, erythromycin and clindamycin was found in 100, 74 and 76% of the isolates, respectively. Seventy-nine percent of herds with a MRSA-positive supplier of pigs were MRSA positive, whereas 23% of herds with a MRSA-negative supplier were MRSA positive (OR=10.8; 95% CI: 1.5–110.1; P=0.011). The presence of entirely MRSA-positive and MRSA-negative chains and the strong association between the MRSA status of herds and their suppliers illustrates a large risk associated with purchasing pigs from MRSA-positive herds; a top-down strategy for future control programs is, therefore, a basic requirement. However, 23% of herds with a MRSA-negative supplier were MRSA positive and furthermore, 46% of the herds at the top of the pig production chain without a supplier tested MRSA positive. This underlined the need for the identification of additional risk factors for MRSA.

In recent years, a new type of MRSA, now called livestock-associated MRSA (LA-MRSA), belonging to the clonal complex (CC) 398, has globally emerged in swine world wide.Aim of this study was to gain more insight into the persistence of LA-MRSA in different types of pig farms over a period of two years.To investigate this, 15 MRSA-positive herds from a previous study were selected; an additional pig farm was selected because this one was found to be positive with a human MRSA-strain.Starting in September 2009, five dust samples were collected every two months.Samples were analysed for MRSA and spa-typing was done to confirm that MRSA isolates belonged to CC398 and to gain insight into persistence of strains within a farm.Three herds were positive on all sampling occasions and were consistently contaminated with LA-MRSA.In the remaining herds, occasionally no positive dust samples were found at some sampling moments.The predominating spa -types were t011 and t108.A maximum of 5 different spa-types were found in two herds, with 3 different spa-types present in one sampling, indicating multiple introductions.These results show that LA-MRSA remains present on a pig farm over a long period.Most likely, transmission within the herd occurs after initial introduction, and an endemic situation seems to be the endpoint.The relatively low sensitivity of dust sampling compared to sampling of animals, the small sample size and lack of strict standardization of dust sampling might explain occasional negative samplings in overall positive herds.However, a true change of a positive MRSA-status to a negative status, followed by re-introduction cannot be ruled out in our study design.

Since the first report on methicillin resistant Staphylococcus aureus (MRSA) CC398 in pigs, several countries have determined the prevalence of MRSA-positive pig herds using different sampling and laboratory techniques. The objective of the study was to compare three sampling methods for MRSA-classification of herds. Therefore, nasal swabs of pigs and environmental wipes were collected from 147 herds with breeding pigs. Per herd, laboratory examination was done on 10 pools of 6 nasal swabs (NASAL), 5 single environmental wipes (ENVSINGLE) and one pool of 5 environmental wipes (ENVPOOL). Large differences in apparent prevalence of MRSA-positive herds between methods were found: 19.1% for ENVPOOL, 53.1% for ENVSINGLE, and 70.8% for NASAL. Pairwise comparisons of methods resulted in relative sensitivities of 26.9% (ENVPOOL vs. NASAL), 34.6% (ENVPOOL vs. ENVSINGLE), and 72.1% (ENVSINGLE vs. NASAL) with relative specificities of respectively 100%, 98.6% and 93.0%. Cohen's kappa was respectively 0.18, 0.32 and 0.55, thus varying between very poor and moderate agreement. Examination of environmental wipes is an easy and non-invasive method to classify herds for MRSA. The number of environmental wipes needed depends on e.g. required detection limits and within-herd prevalence. In low prevalent herds (e.g. herds with <3 positive pools of nasal swabs), 25 single environmental wipes are required to be 90% sure that MRSA is detected at a detection limit similar to analyzing 10 pools of nasal swabs. Individual analysis of environmental wipes is highly recommended, as pooling 5 environmental samples resulted in a substantial reduction of the apparent prevalence.

The Dutch government has obliged the pig industry to reduce the use of antimicrobials at farm level with 50% by 2013. The search for alternatives for antimicrobials and other tools which can improve the health status of the farm is intensified. One example of an alternative for antimicrobials is Daafit, a combination of lauric acid and glycerol-mono-laurate, produced by the firm Daavision B.V..

In 2005, methicillin-resistant Staphylococcus aureus was found in pig herds and in humans in contact with pigs. To determine the prevalence of, this now-called livestock-associated (LA) MRSA among pig herds in The Netherlands and to identify and quantify risk factors, an observational study of 202 pig herds was performed between 2007 and 2008. Five environmental wipes and 60 nasal swabs from each herd were collected, and microbiological analysis was performed on single environmental samples and pooled nasal samples. A herd was considered MRSA-positive if ≥1 sample tested positive. The prevalence of MRSA-positive herds was 67% in breeding herds and 71% in finishing herds. Multivariable logistic regression analysis was then performed on data from 171 breeding herds. The number of MRSA-positive herds increased from ∼30% at the start to ∼75% at the end of the study, most likely due to transmission between herds. The prevalence of MRSA increased with herd size, as ∼40% of smaller herds (<250 sows) were MRSA-positive compared to >80% of larger herds (>500 sows). Other risk factors (e.g. antimicrobial use, purchase of gilts and hygiene measures) were not significantly associated with MRSA, though associated with herd size. Herd size appeared to be a compilation of several factors, which made larger herds more often MRSA positive.

The prevalence of methicillin resistant Staphylococcus aureus (MRSA) in pigs at abattoirs is higher than in pigs sampled on farms. This study investigated whether MRSA negative pigs can become MRSA positive during transportation from the farm to the abattoir after exposure to other pigs and environmental sources of MRSA. Nasal swabs were collected from four batches of pigs during loading at the farm, on arrival at the abattoir and after stunning. Environmental wipes were taken from lorries after transporting pigs and from lairages after holding pigs. All pigs (n=117) tested MRSA negative before transportation. On arrival at the abattoir, 12/117 (10.3%) pigs in two batches tested MRSA positive. In lorries that tested positive after transportation, the prevalence of MRSA positive pigs was 21.1%, whereas no MRSA was detected in pigs that had been transported in lorries that tested negative after transportation. At stunning, all batches and 70/117 (59.8%) pigs tested MRSA positive. Pigs can become MRSA positive in the short period of time during transportation from the farm to stunning at the abattoir.

This study was set up to get more insights in the severity and relevance of porcine circovirus type 2 (PCV2) infections in Dutch fattening farms in an endemic PCV2-situation with no clinical signs of post-weaning multisystemic wasting syndrome (PMWS). In part A of the study, in total 29 commercial fattening farms with varying percentages of pneumonia and pleurisy at slaughter were examined. Blood samples were collected at random by cross-sectional sampling; 10 in the age of 10-12 weeks, 10 at the age of 16 weeks and 10 blood samples at the end of the finishing period (20-22 weeks of age). Serum samples were examined for the presence of PCV2 IgM and IgG antibodies and for antibodies against other porcine lung pathogens. In part B, 8 "high" and 8 "low" herds were selected. The 8 "high" herds were defined as herds having high percentages of lung lesions (pneumonia) at slaughter, and the 8 "low" herds had low percentages of pneumonia at slaughter. For both the "high" and "low" herds, 3 pigs showing signs of respiratory distress were selected for necropsy (n=48). Lung tissue samples were examined post-mortem for macroscopic and histopathological lesions, and for the presence of bacteria and viruses. The results of part A showed that, pigs at 16 weeks of age with IgM antibodies against PCV2 had a lower probability of having pleuritis at slaughter (OR 0.34, P<0.000). Pigs in the age category of 20-22 weeks, and with IgM antibodies against PCV2, also had a lower probability of having pneumonia at slaughter (OR 0.29, P=0.032). In part B lobus apicalis pneumonia, PCV2 in macroscopically unaffected lungs, Pasteurella multocida, Mycoplasma hyopneumoniae, and swine influenza viruses were all found significantly more often in "high" than in "low" pigs at autopsy. High PCV2 DNA loads (>10(4) PCV2 DNA copies/mg) were found in lungs of 14 (58%) "high", and in 7 (29%) of the "low" pigs (P=0.13). In 11 of the 19 affected lungs from "high" pigs, high PCV2 DNA loads were found in combination with one or more other lung pathogens, while this was found only in 5 of the 17 affected lungs from "low" pigs (P=0.02). This study confirms the hypothesis that PCV2 plays a role in pneumonia and pleurisy in 10-24 weeks old fattening pigs, not only in herds with a high prevalence of PMWS, but also in herds with no clinical signs of PMWS.