No abstract

A recent outbreak of mortality in Australian abalone was associated with neurotropic lesions, which have not previously been described in this country. The on farm and between farm pattern of spread of the outbreak, a history of abalone movements linking farms, clinical observation of moribund and dead abalone were all highly suggestive of a virulent infectious agent.

No abstract

No abstract

Abstract. Porcine reproductive and respiratory syndrome (PRRS) is caused by an unclassified arterivirus. The syndrome was first reported in the USA in 1987 as epizootics of reproductive failure in sows and respiratory disease in nursery, growing, and fattening pigs. An enzootic form of the disease has now emerged, characterized by interstitial pneumonia and an increased incidence of secondary infections. Because the disease has now become enzootic on many farms, rodents were investigated as a possible reservoir for the infection. Wild rodents from an endemically infected farm were trapped, and virus isolation for PRRS virus (PRRSV) was attempted using porcine primary alveolar macrophage cultures. PRRSV was not isolated from serum and selected pooled tissues (thymus, lung, and spleen) of 14 feral mice and 2 feral rats. Also, transmission experiments were carried out on 3-week-old Balb/c mice and 12-week-old Fischer-344 rats to determine if these species were susceptible to infection. The rodents were inoculated intranasally, orally, and intraperitoneally with a virus proven to transmit PRRS to pigs. Virus isolations from selected pooled tissues (lung, spleen, thymus, and kidney) and from serum were negative, and there were neither gross nor microscopic lesions. Weight gains and white blood cell counts were not significantly different between treated and control groups. These results indicate that rodents are not susceptible to infection with PRRSV and therefore are probably not a reservoir for the disease.