Dendritic Cell Subtypes from Lymph Nodes and Blood Show Contrasted Gene Expression Programs upon Bluetongue Virus Infection

Chantier qualité GAHuman and animal hemorrhagic viruses initially target dendritic cells (DCs). It has been proposed, but not documented, that both plasmacytoid DCs (pDCs) and conventional DCs (cDCs) may participate in the cytokine storm encountered in these infections. In order to evaluate the contribution of DCs in hemorrhagic virus pathogenesis, we performed a genome-wide expression analysis during infection by Bluetongue virus (BTV), a double-stranded RNA virus that induces hemorrhagic fever in sheep and initially infects cDCs. Both pDCs and cDCs accumulated in regional lymph nodes and spleen during BTV infection. The gene response profiles were performed at the onset of the disease and markedly differed with the DC subtypes and their lymphoid organ location. An integrative knowledge-based analysis revealed that blood pDCs displayed a gene signature related to activation of systemic inflammation and permeability of vasculature. In contrast, the gene profile of pDCs and cDCs in lymph nodes was oriented to inhibition of inflammation, whereas spleen cDCs did not show a clear functional orientation. These analyses indicate that tissue location and DC subtype affect the functional gene expression program induced by BTV and suggest the involvement of blood pDCs in the inflammation and plasma leakage/hemorrhage during BTV infection in the real natural host of the virus. These findings open the avenue to target DCs for therapeutic interventions in viral hemorrhagic diseases

Strict Biosecurity and Epidemiological Segmentation Enable Partial Culling During a Highly Pathogenic Avian Influenza Outbreak

Martin J Oettler,1,* Gerald Stumpf,2,* Katja Schulz,1 Matthias Todte,3 Klim Hüttner,4 Heidemarie Heyne,5 Thomas C Mettenleiter,6 Franz J Conraths,1 Carola Sauter-Louis1 1Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493, Germany; 2Veterinary and Food Inspection Office, Güstrow, 18273, Germany; 3Veterinary Practice MMT, Köthen (Anhalt) 06366, Germany; 4Veterinary Epidemiological Service, State Institute for Agriculture, Food Safety and Fisheries Mecklenburg-Western Pomerania, Rostock, 18059, Germany; 5Animal Health Division, Ministry for Climate Protection, Agriculture, Rural Areas and the Environment of Mecklenburg-Western Pomerania, Schwerin, 19061, Germany; 6Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493, Germany*These authors contributed equally to this workCorrespondence: Martin J Oettler, Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Greifswald-Insel Riems, 17493, Germany, Email [email protected]: The mandatory procedures to be followed after official confirmation of an outbreak of category A animal infectious diseases, including highly pathogenic avian influenza (HPAI), is laid down in European and national legislation. Typically, an outbreak of HPAI results in the destruction of the entire poultry population on the affected holding.Case Presentation: The presented case reports a deviation from this approach, demonstrating the practicality of partial culling in a highly biosecure, epidemiologically segmented holding. These on-site circumstances together with the specific risk assessment led to the elimination of only the affected unit, thereby inhibiting the further spread of the disease. After the destruction of the respective unit (farm), the other farms were closely monitored and tested continuously negative for HPAI virus (HPAIV) despite intensive systematic sampling. In the end, this procedure saved approximately 138,000 animals, ie 75% of the poultry population of the holding from destruction.Conclusion: This case demonstrates the effectiveness of proper management and high-level biosecurity to avoid excessive destruction of animals in case of an infectious disease outbreak. It might be suitable as a best-practice example in similar situations.Keywords: epidemiology, epidemiological unit, biosafety, infectious animal diseases, poultr

Financial Evaluation of Different Vaccination Strategies for Controlling the Bluetongue Virus Serotype 8 Epidemic in the Netherlands in 2008

Background: Bluetongue (BT) is a vector-borne disease of ruminants caused by bluetongue virus that is transmitted by biting midges (Culicoides spp.). In 2006, the introduction of BTV serotype 8 (BTV-8) caused a severe epidemic in Western and Central Europe. The principal effective veterinary measure in response to BT was believed to be vaccination accompanied by other measures such as movement restrictions and surveillance. As the number of vaccine doses available at the start of the vaccination campaign was rather uncertain, the Dutch Ministry of Agriculture, Nature and Food Quality and the Dutch agricultural industry wanted to evaluate several different vaccination strategies. This study aimed to rank eight vaccination strategies based on their efficiency (i.e. net costs in relation to prevented losses or benefits) for controlling the bluetongue virus serotype 8 epidemic in 2008 Methodology/Principal Findings: An economic model was developed that included the Dutch professional cattle, sheep and goat sectors together with the hobby farms. Strategies were evaluated based on the least cost - highest benefit frontier, the benefit-cost ratio and the total net returns. Strategy F, where all adult sheep at professional farms in the Netherlands would be vaccinated was very efficient at lowest costs, whereas strategy D, where additional to all adult sheep at professional farms also all adult cattle in the four Northern provinces would be vaccinated, was also very efficient but at a little higher costs. Strategy C, where all adult sheep and cattle at professional farms in the whole of the Netherlands would be vaccinated was also efficient but again at higher costs. Conclusions/Significance: This study demonstrates that a financial analysis differentiates between vaccination strategies and indicates important decision rules based on efficienc

Virus-induced congenital malformations in cattle

Diagnosing the cause of bovine congenital malformations (BCMs) is challenging for bovine veterinary practitioners and laboratory diagnosticians as many known as well as a large number of not-yet reported syndromes exist. Foetal infection with certain viruses, including bovine virus diarrhea virus (BVDV), Schmallenberg virus (SBV), blue tongue virus (BTV), Akabane virus (AKAV), or Aino virus (AV), is associated with a range of congenital malformations. It is tempting for veterinary practitioners to diagnose such infections based only on the morphology of the defective offspring. However, diagnosing a virus as a cause of BCMs usually requires laboratory examination and even in such cases, interpretation of findings may be challenging due to lack of experience regarding genetic defects causing similar lesions, even in cases where virus or congenital antibodies are present. Intrauterine infection of the foetus during the susceptible periods of development, i.e. around gestation days 60–180, by BVDV, SBV, BTV, AKAV and AV may cause malformations in the central nervous system, especially in the brain. Brain lesions typically consist of hydranencephaly, porencephaly, hydrocephalus and cerebellar hypoplasia, which in case of SBV, AKAV and AV infections may be associated by malformation of the axial and appendicular skeleton, e.g. arthrogryposis multiplex congenita. Doming of the calvarium is present in some, but not all, cases. None of these lesions are pathognomonic so diagnosing a viral cause based on gross lesions is uncertain. Several genetic defects share morphology with virus induced congenital malformations, so expert advice should be sought when BCMs are encountered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13028-015-0145-8) contains supplementary material, which is available to authorized users