Field infectious bursal disease viruses 9IBDVs) were isolated from IBDV-suspected commercial chickens. The variable region in VP2 gene of six Korean IBDV isolates (K-IBDVs) and IBD vaccines was examined using the reverse transcriptase/polymerase chain reaction-restriction fragment length polymorphism (RT/PCR-RFLP) assay. With all K-IBDVs and vaccine IBDVs, a 474-bp fragment of the VP2 gene was amplified and tested with various restriction enzymes. Resseriction enzymes BstNI and StyI differentiated K-IBDV isolates and IBD vaccines into four groups. Reseriction enzyme profiles of K-IBDV isolates were different from them of IBD vaccines. K-IBDV isolates except for 310 isolate had specific SspI and TaqI recognition sites, which were recognized in highly virulent IBDVs, but IBD vaccines had no those sites. This study showed that RT/PCR-RFLP assay was thought to be valuable tool for differentiation of IBDVs and identification of highly virulent IBDV.

This study was carried out for investigation of an outbreak in Karachi. A disease outbreak in poultry was reported during April, 2000 in Karachi. The main symptoms included respiratory distress, sneezing and gasping. Autopsy of dead birds showed tracheitis, air-sacculitis and involvement of lungs. The morbid material was collected for processing in the laboratory. During the investigation for isolation of pathogenic bacteria or virus, Ornithobacterium rhinotracheale was isolated on 5% sheep blood agar plates in an atmosphere containing 5-10% CO2 at 37 degree C and identified through biochemical and fermentation tests. A Lasota like virus was also isolated from the same material which showed HA activity but was found negative to Avian Influenza virus against known Avian Influenza serum. The isolated virus was sent to Central Veterinary Laboratory, Weybridge, U.K. which confirmed it to be Lasota virus having comparatively high Intracerebral Pathogenicity Index (ICPI) as 0.90. Attempts for the transmission of the disease in susceptible healthy broiler chicks was successful through aerosol route using combination of inoculum of the isolated bacteria and virus. On post-mortem of infected birds air- sacculitis, tracheitis and unilateral pneumonia were noticed. Again ORT and NDV were isolated from the material harvested from these chicks. According to the observations of these experiments, it was concluded that the isolated ORT had a triggering effect on Lasota virus or vice versa. The environmental temperature and other stress factors might have aggravated the disease problem.

There was studied the epizootic conditions on cattle rotavirus infections by the analysis of veterinary reporting of diagnostic organizations of Belarus and results of own research. Results of the data analysis about spreading of cattle rotavirus infection from 2002 for 2006 are presented. The material analysis has allowed to conclude, that annually in Belarus on rotavirus infections is registered on the average about 30 unsuccessful points. The obtained data testify that lethality for the reason of rotavirus infections makes calves from 15,9 to 32,9%. Decrease, in comparison with previous years, quantities fallen for the reason of rotavirus infections of calves testifies to purposefully spent specific preventive maintenance of the given infection, however lethality at rotavirus to an infection remains practically at one level. In the tabular form results of virology research of regional veterinary laboratory on cattle rotavirus infection on corresponding areas of Belarus are presented. From the data resulted in the table it is visible, that rotavirus allocation percent in various regions of the republic made from 9,8 to 56,7% at calves sick with enteritis. | Эпизоотическую обстановку по ротавирусной инфекции крупного рогатого скота устанавливали путем анализа ветотчетности диагностических учреждений Республики Беларусь и результатов собственных исследований. Представлены результаты анализа данных о распространении ротавирусной инфекции крупного рогатого скота за период с 2002 по 2006 годы. Анализ материала позволил заключить, что ежегодно в Республике Беларусь по ротавирусной инфекции регистрируется в среднем около 30 неблагополучных пунктов. Полученные данные свидетельствуют о том, что летальность телят по причине ротавирусной инфекции составляет от 15,9 до 32,9%. Снижение, в сравнении с предыдущими годами, количества павших по причине ротавирусной инфекции телят свидетельствует о целенаправленно проводимой специфической профилактике данной инфекции, однако летальность при ротавирусной инфекции остается практически на одном уровне. В табличной форме представлены результаты вирусологических исследований областных ветлабораторий на ротавирусную инфекцию крупного рогатого скота по соответствующим областям Республики Беларусь. Из приведенных в таблице данных видно, что процент выделения ротавируса в различных областях республики составлял от 9,8 до 56,7% у обследованных больных энтеритами телят.