RESUMEN
The most effective and sustainable method to control and eliminate rabies in wildlife is the oral rabies vaccination (ORV) of target species, namely foxes and raccoon dogs in Europe. According to WHO and OIE, the effectiveness of oral vaccination campaigns should be regularly assessed via disease surveillance and ORV antibody monitoring. Rabies antibodies are generally screened for in field animal cadavers, whose body fluids are often of poor quality. Therefore, the use of alternative methods such as the enzyme-linked immunosorbent assay (ELISA) has been proposed to improve reliability of serological results obtained on wildlife samples. We undertook an international collaborative study to determine if the commercial BioPro ELISA Rabies Ab kit is a reliable and reproducible tool for rabies serological testing. Our results reveal that the overall specificity evaluated on naive samples reached 96.7%, and the coefficients of concordance obtained for fox and raccoon dog samples were 97.2% and 97.5%, respectively. The overall agreement values obtained for the four marketed oral vaccines used in Europe were all equal to or greater than 95%. The coefficients of concordance obtained by laboratories ranged from 87.2% to 100%. The results of this collaborative study show good robustness and reproducibility of the BioPro ELISA Rabies Ab kit.
Asunto(s)
Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Programas de Inmunización , Vacunas Antirrábicas/inmunología , Virus de la Rabia/inmunología , Rabia/veterinaria , Administración Oral , Animales , Animales Salvajes/virología , Zorros/virología , Cooperación Internacional , Rabia/epidemiología , Rabia/inmunología , Rabia/prevención & control , Vacunas Antirrábicas/administración & dosificación , Perros Mapache/virología , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
In 2005, an outbreak of severe respiratory disease in a mixed poultry flock that was infected with Chlamydophila (C.) psittaci led to dissemination of the infection to at least 100 small poultry farms in 11 districts of Central Germany. At the same time, a total of 24 persons in contact with poultry from one of the flocks reported flu-like symptoms to their physician, thus suggesting zoonotic transmission. Within 3 weeks, seven individuals had to be hospitalized, with three of them requiring intensive care. Analysis of ompA sequences from chlamydial isolates and directly from clinical samples revealed the presence of both genotype A and E/B of C. psittaci at the source of the outbreak and in contact flocks. Genotype A was also detected in the three severely ill patients. The findings of the present study demonstrate the high zoonotic potential of avian chlamydiae. To ensure speedy eradication of psittacosis in poultry flocks and effective treatment of infected humans, fast, sensitive and species-specific detection of the causative agent is essential, as well as close collaboration between regional public health services, attending physicians and the diagnostic laboratories involved.
Asunto(s)
Chlamydophila psittaci/patogenicidad , Enfermedades de las Aves de Corral/transmisión , Psitacosis/transmisión , Psitacosis/veterinaria , Salud Pública , Zoonosis , Animales , Proteínas de la Membrana Bacteriana Externa/genética , Chlamydophila psittaci/genética , ADN Bacteriano/química , Brotes de Enfermedades/veterinaria , Femenino , Genotipo , Alemania/epidemiología , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Aves de Corral , Enfermedades de las Aves de Corral/diagnóstico , Enfermedades de las Aves de Corral/epidemiología , Psitacosis/diagnóstico , Psitacosis/epidemiología , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
The incidence of bovine viral diarrhoea virus (BVDV) 1 and 2 infections was determined in calves, young cattle and older cattle with signs of mucosal disease (MD) submitted for necropsy to three laboratories in Northern Germany between June 2000 and May 2001. At necropsy, tonsils, retropharyngeal lymph nodes, mesenteric lymph nodes, ileal Peyer's patch and spleen were collected and examined by immunohistochemistry and virus isolation. From 311 animals examined, 30 (9.6%) were positive for BVDV. All viral isolates were typed by polymerase chain reaction after reverse transcription using species-specific primers and determined to be BVDV1. Based on the distribution of lesions and viral antigen, animals with MD, persistent infection (PI) and acute, transient infection could be distinguished. Twelve of the positive animals had characteristic signs of MD: severe diarrhoea, erosive to ulcerative lesions throughout the digestive tract and severe depletion of all lymphoid tissues. Viral antigen was present in all tissues and cell types, but particularly in depleted lymphoid follicles and altered epithelium. In seven calves, viral antigen was detectable in all tissues and cell types, but lesions were mild or missing. This is typical for PI. The remaining 11 calves most likely represent animals with acute, transient infection. Distribution of antigen was more variable, predominantly restricted to lymphoid follicles and often not seen in all tissues examined. Clinical findings were combined bronchopneumonia and enteritis. The detection of BVDV1 in young calves with pneumonia and enteritis emphasizes the importance of BVDV1 and not only BVDV2 for severe respiratory and enteric diseases of calves.
Asunto(s)
Antígenos Virales/inmunología , Diarrea Mucosa Bovina Viral/epidemiología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Tejido Linfoide/virología , Animales , Diarrea Mucosa Bovina Viral/patología , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Alemania/epidemiología , Inmunohistoquímica/métodos , Inmunohistoquímica/veterinaria , Tejido Linfoide/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinariaRESUMEN
In order to assess the efficacy of a two-step vaccination protocol with respect to foetal protection against transplacental infections with bovine virus diarrhoea virus (BVDV) with special attention to BVDV-2 seronegative heifers were vaccinated with an inactivated BVDV-1 vaccine and boostered with a modified live BVDV-1 vaccine after 4 weeks. A second group was left unvaccinated as control. Between days 30 and 120 of pregnancy the heifers of both groups were intranasally challenged with a mixture of BVDV-1 and -2. All heifers of the vaccinated group gave birth to nine clinically healthy, seronegative (precolostral) and BVDV-free calves. In contrast in the control group four BVDV viraemic underdeveloped calves were born. Additionally, one calf was stillborn and another viraemic calf was not viable and died 2 days after birth. All six calves of the control group were viraemic with BVDV-2. This study demonstrated for the first time that two-step vaccination of breeding cattle with a modified live BVDV vaccine 4 weeks after application of an inactivated BVDV vaccine was capable of providing a foetal protection against transplacental infection with BVDV-2.