Assessing the Efficacy of Recombinant Newcastle Disease Virus Vaccines (Double-Insert vHVT-IBD-ND and Single-Insert vHVT-ND) Followed by a Vaccination with a Live Newcastle Disease Vaccine Against a Moroccan Velogenic Newcastle Disease Challenge in Commercial Broilers.

The advent of turkey herpesvirus (HVT) vector vaccine technology (vHVT) has made a huge improvement in the prevention and control of several poultry diseases. The objective of this study was to compare, under experimental conditions, the protection conferred by different vaccination programs based on an HVT double-insert (infectious bursal disease {IBD] and Newcastle disease [ND]) vector vaccine (vHVT-IBD-ND) and an HVT single-insert (vHVT-ND) vector vaccine followed by a vaccination with a live ND vaccine at Day 1 only or at Days 1 and 14. Commercial broilers were vaccinated by the recombinant ND virus vaccines subcutaneously at 1 day old, in the hatchery, and challenged at 30 days of age using the Moroccan ND virus velogenic viscerotropic JEL strain. The results showed that the tested vaccine induced 95% to 100% clinical protection against mortality and clinical signs. The humoral immune response to vaccination was detected from 3 wk of age using enzyme-linked immunosorbent assay and hemagglutination inhibition tests. ND challenge virus shedding was significantly reduced in the vaccinated birds as compared to controls. Significant reduction of the cloacal shedding suggests that the vHVT-IBD-ND vaccine stimulates actively the immunity against the tested ND challenge virus. No significant differences were found between the vaccination programs based on vHVT-IBD-ND or on vHVT-ND.

Evaluación de la eficacia de las vacunas recombinantes contra el virus de la enfermedad de Newcastle (vHVT-IBD-ND de doble inserto y vHVT-ND de inserto único) seguidas de una vacunación con una vacuna viva para la enfermedad de Newcastle contra un desafío de la enfermedad de Newcastle velogénico marroquí en pollos de engorde comerciales. El advenimiento de la tecnología de vacunas recombinantes (vHVT) del virus herpes del pavo (HVT) ha provocado una mejora en la prevención y el control de varias enfermedades avícolas. El objetivo de este estudio fue comparar, en condiciones experimentales, la protección conferida por diferentes programas vacunales basados en una vacuna recombinante HVT con doble inserto (bursitis infecciosa [EII] y enfermedad de Newcastle [ND]) (vHVT-IBD-ND) y una vacuna recombinante HVT con inserto única (vHVT-ND) seguida de una vacunación con una vacuna para Newcastle viva aplicada en el día 1 o en los días 1 y 14. Pollos de engorde comerciales se vacunaron con las vacunas recombinantes del virus de la enfermedad de Newcastle por vía subcutánea al día de edad, en la incubadora y se expusieron a los 30 días de edad utilizando la cepa JEL viscerotrópica velogénica del virus de la enfermedad de Newcastle de Marruecos. Los resultados mostraron que la vacuna evaluada indujo una protección clínica del 95% al 100% contra la mortalidad y los signos clínicos. La respuesta inmune humoral a la vacunación se detectó a partir de las 3 semanas de edad mediante ensayo inmunoabsorbente ligado a enzimas y pruebas de inhibición de la hemaglutinación. La excreción del virus de Newcastle de desafío se redujo significativamente en las aves vacunadas en comparación con los controles. La reducción significativa de la eliminación cloacal sugiere que la vacuna vHVT-IBD-ND estimula activamente la inmunidad contra el virus de Newcastle de desafío analizado. No se encontraron diferencias significativas entre los programas de vacunación basados en vHVT-IBD-ND o en vHVT-ND.

Pathogenesis of Avian Influenza Virus Subtype H9N2 in Turkeys and Evaluation of Inactivated Vaccine Efficacy.

Avian influenza H9N2 viruses circulate in all types of poultry species, including turkeys, and cause significant losses for the poultry industry in many parts of the word. The aim of this study was to assess the pathogenesis of the Moroccan avian influenza virus (AIV) H9N2 under experimental conditions in turkeys and the protection efficacy of an inactivated commercial vaccine against AIV H9N2. Unvaccinated turkeys showed marked depression sinusitis, respiratory distress characterized by bronchiolar and tracheal rales of moderate severity, and a mortality rate of 50%. Postmortem examinations of dead and euthanatized birds revealed the presence of fibrinous tracheitis and airsacculitis lesions. Vaccination reduced the mortality rate to 20%. Vaccinated birds recovered at day 10 postchallenge, and only 12.5% (1/8) and 37.5% of birds still displayed fibrinous and nonfibrinous airsacculitis lesions, respectively, at day 15 postinoculation. Viral shedding in cloacal and tracheal swabs was lower in vaccinated than in control birds. Although viral RNA was detected in the cloacal swabs of all unvaccinated turkeys at day 3 postinoculation, only 50% of the vaccinated turkeys were positive for virus detection. At day 11 postinoculation, no viral RNA was detected in oropharyngeal swabs of vaccinated turkeys, whereas 40% of the unvaccinated turkeys were still shedding virus.

Artículo regular­Patogenia del subtipo H9N2 del virus de la influenza aviar en pavos y evaluación de la eficacia de una vacuna inactivada. Los virus de la influenza aviar H9N2 circulan en todo tipo de especies de aves comerciales, incluidos los pavos, y causan pérdidas significativas para la industria avícola en muchas partes del mundo. El objetivo de este estudio fue evaluar la patogenia del virus de la influenza aviar de Marruecos (AIV) H9N2 bajo condiciones experimentales en pavos y la eficacia de protección de una vacuna comercial inactivada contra el virus de la influenza aviar H9N2. Los pavos no vacunados mostraron una marcada sinusitis, depresión, dificultad respiratoria caracterizada por estertores bronquiolares y traqueales de severidad moderada y una tasa de mortalidad del 50%. Los exámenes post mortem de aves muertas y sacrificadas revelaron la presencia de traqueítis fibrinosa y aerosaculitis. La vacunación redujo la tasa de mortalidad al 30%. Las aves vacunadas se recuperaron en el día 10 después del desafío, y solo el 12.5% (1/8) y el 37.5% de las aves todavía mostraban aerosaculitis fibrinosa y no fibrinosa, respectivamente, el día 15 después de la inoculación. La diseminación viral en los hisopos cloacales y traqueales fue menor en las aves vacunadas que en las aves control. Aunque se detectó ARN viral en los hisopados cloacales de todos los pavos no vacunados en el día tres después de la inoculación, solo el 50% de los pavos vacunados dieron positivo para la detección del virus. En el día 11 después de la inoculación, no se detectó ARN viral en hisopados orofaríngeos de pavos vacunados, mientras que el 40% de los pavos no vacunados todavía estaban diseminando virus.

Use of real-time PCR to rule out Marek's disease in the diagnosis of peripheral neuropathy.

This article reports nine cases of neurological disease in brown layer pullets that occured in various European countries between 2015 and 2018. In all cases, the onset of neurological clinical signs was at 4-8 weeks of age and they lasted up to 22 weeks of age. Enlargement of peripheral nerves was the main lesion observed in all cases. Histopathological evaluation of nerves revealed oedema with moderate to severe infiltration of plasma cells. Marek's disease (MD) was ruled out by real-time PCR as none of the evaluated tissues had a high load of oncogenic MD virus (MDV) DNA, characteristics of MD. Based on the epidemiological data (layers with clinical signs starting at 5-8 weeks of age), gross lesions (peripheral nerve enlargement with a lack of tumours in other organs), histopathological lesions (oedema and infiltration of plasma cells), and no evidence of high load of MDV DNA, we concluded that those cases were due to peripheral neuropathy (PN). PN is an autoimmune disease easily misdiagnosed as MD, leading to a costly enforcement of the vaccination protocol. Additional vaccination against MD does not protect against PN and could worsen the clinical signs by over-stimulating the immune system. Differential diagnosis between PN and MD should always be considered in cases of neurological disease with enlargement of peripheral nerves as the only gross lesion. This case report shows for the first time how real-time PCR to detect oncogenic MDV is a very valuable tool in the differential diagnosis of PN and MD.

Laparoscopic distal pancreatectomy in children: case report and review of the literature.

BACKGROUND: Laparoscopic resection of benign tumors of the pancreas has been reported in adults, but only four cases of partial laparoscopic pancreatectomy in children have been described in the English-language literature. METHODS: We describe the case of an 11-year-old girl with a solid pseudopapillary tumor who was treated with a laparoscopic, spleen-preserving, distal pancreatectomy. The specimen was extracted in an endoscopic bag retrieval system through a Pfannenstiel incision. Operative time was 120 minutes, and minimal blood loss occurred. The literature is reviewed. RESULTS: The postoperative course was uneventful. Twenty-two months after the operation, clinical follow-up (including assessment of exocrine and endocrine pancreatic function) revealed nothing abnormal. The functional and aesthetic results were satisfactory. CONCLUSIONS: The technique used for our case is simple and reproducible, was completed safely within a reasonable operative time, and yielded a good result.