[Performance parameters and pathogen detection in pig groups differently vaccinated with respect to Porcine Circovirus Type 2 and Mycoplasma hyopneumoniae]. / Leistungsparameter und Erregernachweise in unterschiedlich geimpften Tiergruppen in Bezug auf das Porzine Circovirus Typ 2 und Mycoplasma hyopneumoniae.

OBJECTIVE: Respiratory diseases, mostly multifactorial, cause problems in pig farms worldwide. Next to infectious agents, such as Porcine Circovirus Type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyopneumoniae) management, housing, and environmental factors are decisive for the development of disease. In a conventional, closed swine farm in Lower Saxony, Germany, which did not vaccinate against PCV2, the effect of an implementation of PCV2 vaccination (Suvaxyn® Circo + MH RTU) onto animal health was evaluated. In addition, the effect of this combination vaccine was assessed in comparison to simultaneous administration of mono-vaccines against PCV2 and M. hyopneumoniae. MATERIAL AND METHOD: In a two-phase trial, 524 (phase 1) or 521 (phase 2) clinically healthy piglets were included at the first week of life. In the first phase, performance parameters were compared in animals vaccinated against M. hyopneumoniae only (group A) or vaccinated against PCV2 and M. hyopneumoniae (group B). In phase 2, vaccination against PCV2 and M. hyopneumoniae with different vaccines were compared (groups C and D). Performance parameters included lifetime animal losses, daily weight gains during suckling, weaning and fattening, and randomly sampled pathogen loads in serum (PCV2) or tracheobronchial secretions (M. hyopneumoniae). In addition, an assessment of the lungs was performed after slaughter. RESULTS: In the first phase, it was shown that the group vaccinated against PCV2 (Group B: Suvaxyn® Circo + MH RTU) had higher daily growth rates during the fattening period (+ 37 g, p = 0.012) as well as during the complete period (+ 16 g, p = 0.013) in comparison to the group without PCV2 vaccination (Group A). In group A a significantly higher proportion of animals showed a PCV2 viremia. In the second phase, it was shown that group D was not inferior to the established vaccination regiment of group C. In fattening pigs in week 22 of life, detection rates for M. hyopneumoniae in tracheobronchial secretions were in the range of 27-80 % irrespective of the vaccination group. CONCLUSION: Vaccination against PCV2 leads to improved animal health and higher daily weight gains. CLINICAL RELEVANCE: The combined vaccine studied here provides farmers and veterinarians with an additional option for the improvement of animal health in pig production.

[Comparison of sample materials for the detection of infection with porcine reproductive and respiratory syndrome virus]. / Vergleich von Probenmaterialien zur Früherkennung einer Infektion mit dem Virus des Porzinen Reproduktiven und Respiratorischen Syndroms.

OBJECTIVE: In breeding farms with a high health status, pigs are frequently sampled using invasive methods (i. e. blood sampling). The aim of the present study was to evaluate less invasive methods concerning their suitability for an early detection of the infection with the porcine reproductive and respiratory syndrome virus (PRRSV). MATERIAL AND METHODS: Blood and saliva swabs, chewing rope derived oral fluids and serum samples were used for PRRSV-1 and PRRSV-2 detection via PCR. 19 gilts were repeatedly sampled following intramuscular or intranasal vaccination with live-attenuated vaccines containing PRRSV-1 or -2. Swabs were either moistened with saliva from the mouth mucosa or with blood from the ear veins following superficial needle puncture. Serum samples were taken via puncture of the V. jugularis externa. Chewing ropes served for a means of oral fluid sampling and were kept hanging in the barn at the pigs' head height for 30 minutes. RESULTS: All animals were negative for PRRSV at the time of vaccination (sampling point 0). In serum samples, the first virus detection was achieved 12 hours following vaccination (p. vacc.). From day 4 p. vacc. on all animals were viremic and from day 10 p. vacc. on the percentage of positive animals decreased. The first detection of PRRSV in GenoTube® blood swabs was possible 36 hours p. vacc. Examination of the eSwab® blood swab resulted in only one positive finding within the entire testing period. In the saliva samples, first detection of PRRSV was possible on day 5 p. vacc. CONCLUSION AND CLINICAL RELEVANCE: This study demonstrates that serum samples taken from the V. jugularis externa may be considered as the gold standard for diagnostic of PRRSV viremia. Detection rates in serum were higher than in the alternative sample types. However, since sample collection procedures and processing of the alternative sample materials offer clear advantages with regard to welfare, practical handling and logistics, further attempts are warranted in order to improve these methods. Based on the presented results, the described method using eSwab® blood sampling does not represent a satisfactory alternative approach for the detection of early PRRSV infection. Future application of this method warrants further improvement of its diagnostic efficacy.

From Stable to Lab-Investigating Key Factors for Sudden Deaths Caused by Streptococcus suis.

Swine stocks are endemically infected with the major porcine pathogen Streptococcus (S.) suis. The factors governing the transition from colonizing S. suis residing in the tonsils and the exacerbation of disease have not yet been elucidated. We analyzed the sudden death of fattening pigs kept under extensive husbandry conditions in a zoo. The animals died suddenly of septic shock and showed disseminated intravascular coagulopathy. Genotypic and phenotypic characterizations of the isolated S. suis strains, a tonsillar isolate and an invasive cps type 2 strain, were conducted. Isolated S. suis from dead pigs belonged to cps type 2 strain ST28, whereas one tonsillar S. suis isolate harvested from a healthy animal belonged to ST1173. Neither S. suis growth, induction of neutrophil extracellular traps, nor survival in blood could explain the sudden deaths. Reconstituted blood assays with serum samples from pigs of different age groups from the zoo stock suggested varying protection of individuals against pathogenic cps type 2 strains especially in younger pigs. These findings highlight the benefit of further characterization of the causative strains in each case by sequence typing before autologous vaccine candidate selection.

Decontamination of high-risk animal and zoonotic pathogens.

Preparedness for the decontamination of affected environments, premises, facilities, and products is one prerequisite for an immediate response to an animal disease outbreak. Various information sources provide recommendations on how to proceed in an outbreak situation to eliminate biological contaminants and to stop the spread of the disease. In order to facilitate the identification of the right decontamination strategy, we present an overview of relevant references for a collection of pathogenic agents. The choice of pathogens is based on a survey of lists containing highly pathogenic agents and/or biological agents considered to be potential vehicles for deliberate contamination of food, feed, or farm animals. European legislation and guidelines from national and international institutions were screened to find decontamination protocols for each of the agents. Identified recommendations were evaluated with regard to their area of application, which could be facilities and equipment, wastes, food, and other animal products. The requirements of a disinfectant for large-scale incidents were gathered, and important characteristics (eg, inactivating spectrum, temperature range, toxicity to environment) of the main recommended disinfectants were summarized to assist in the choice of a suitable and efficient approach in a crisis situation induced by a specific high-risk animal or zoonotic pathogen. The literature search revealed numerous relevant recommendations but also legal gaps for certain diseases, such as Q fever or brucellosis, and legal difficulties for the use of recommended disinfectants. A lack of information about effective disinfectants was identified for some agents.

Historical perspective on agroterrorism: lessons learned from 1945 to 2012.

This article presents a historical perspective on agroterrorism cases from 1945 until 2012. The threat groups and perpetrators associated with bio- and agroterrorism are clustered into several groups: apocalyptic sects, lone wolves, political groups, and religious groups. We used open-source information, and 4 biological agroterrorism cases are described: (1) in 1952, Mau Mau poisoned cattle in Kenya by using a plant toxin from the African milk bush plant; (2) in 1985, the USDA claimed that Mexican contract workers were involved in deliberately spreading screwworm (Cochliomyia hominivorax) among livestock; (3) in 2000, Palestinian media reported that Israeli settlers released sewer water into Palestinian agricultural fields; and (4) in 2011, a person was sentenced to prison after threatening US and UK livestock with the deliberate spread of foot-and-mouth disease virus. All 4 cases can be assigned to political groups. These cases have not attracted much attention in literature nor in the public media, and the credibility of the sources of information varies. We concluded that agroterrorism has not been a problem during the period studied. Lessons learned from the few cases have generated awareness about the fact that nontypical biological weapons and non-high-risk agents, such as African milk bush, screwworm, and sewer water, have been used by attackers to influence local decision makers. This review will be useful in improving future preparedness planning and developing countermeasures.

Separated by a common language: awareness of term usage differences between languages and disciplines in biopreparedness.

Preparedness for bioterrorism is based on communication between people in organizations who are educated and trained in several disciplines, including law enforcement, health, and science. Various backgrounds, cultures, and vocabularies generate difficulties in understanding and interpretating terms and concepts, which may impair communication. This is especially true in emergency situations, in which the need for clarity and consistency is vital. The EU project AniBioThreat initiated methods and made a rough estimate of the terms and concepts that are crucial for an incident, and a pilot database with key terms and definitions has been constructed. Analysis of collected terms and sources has shown that many of the participating organizations use various international standards in their area of expertise. The same term often represents different concepts in the standards from different sectors, or, alternatively, different terms were used to represent the same or similar concepts. The use of conflicting terminology can be problematic for decision makers and communicators in planning and prevention or when handling an incident. Since the CBRN area has roots in multiple disciplines, each with its own evolving terminology, it may not be realistic to achieve unequivocal communication through a standardized vocabulary and joint definitions for words from common language. We suggest that a communication strategy should include awareness of alternative definitions and ontologies and the ability to talk and write without relying on the implicit knowledge underlying specialized jargon. Consequently, cross-disciplinary communication skills should be part of training of personnel in the CBRN field. In addition, a searchable repository of terms and definitions from relevant organizations and authorities would be a valuable addition to existing glossaries for improving awareness concerning bioterrorism prevention planning.

Development of a comparative risk ranking system for agents posing a bioterrorism threat to human or animal populations.

Various systems for prioritizing biological agents with respect to their applicability as biological weapons are available, ranging from qualitative to (semi)quantitative approaches. This research aimed at generating a generic risk ranking system applicable to human and animal pathogenic agents based on scientific information. Criteria were evaluated and clustered to create a criteria list. Considering availability of data, a number of 28 criteria separated by content were identified that can be classified in 11 thematic areas or categories. Relevant categories contributing to probability were historical aspects, accessibility, production efforts, and possible paths for dispersion. Categories associated with impact are dealing with containment measures, availability of diagnostics, preventive and treatment measures in human and animal populations, impact on society, human and veterinary public health, and economic and ecological consequences. To allow data-based scoring, each criterion was described by at least 1 measure that allows the assignment of values. These values constitute quantities, ranges, or facts that are as explicit and precise as possible. The consideration of minimum and maximum values that can occur due to natural variations and that are often described in the literature led to the development of minimum and maximum criteria and consequently category scores. Missing or incomplete data, and uncertainty resulting therefrom, were integrated into the scheme via a cautious (but not overcautious) approach. The visualization technique that was used allows the description and illustration of uncertainty on the level of probability and impact. The developed risk ranking system was evaluated by assessing the risk originating from the bioterrorism threat of the animal pathogen bluetongue virus, the human pathogen Enterohemorrhagic Escherichia coli O157:H7, the zoonotic Bacillus anthracis, and Botulinum neurotoxin.

Shiga toxin producing Escherichia coli: identification of non-O157:H7-Super-Shedding cows and related risk factors.

BACKGROUND: Shiga toxin producing Escherichia coli (STEC) are an important cause of human gastro-enteritis and extraintestinal sequelae, with ruminants, especially cattle, as the major source of infection and reservoir. In this study, the fecal STEC shedding of 133 dairy cows was analyzed over a period of twelve months by monthly sampling with the aim to investigate shedding patterns and risk factors. RESULTS: Overall, 24.7% (in total 407) of 1,646 fecal samples were tested positive for stx by PCR with inner-herd prevalences on the different farms of 11.1% to 32.3%. At individual levels, cows were stx-positive on zero to eight consecutive samplings. According to a strictly longitudinal definition of Super-Shedding, in the present study 14 cows were identified as Super-Shedders of non-O157 serotypes.Significant risk factors for the shedding of STEC were the month of sampling, the number of lactations and days in lactation, the nutritional condition, the somatic cell count and the content of protein in milk. Most notably, the presence of STEC Super-Shedding cows in the herd was a significant risk factor, revealing that STEC Super-Shedding is not restricted to STEC O157:H7 alone. CONCLUSIONS: These data have implications for possible interventions, as removing single non-O157:H7 STEC Super-Shedding cattle from farms would significantly reduce STEC burden.