Pathogenicity and distribution of avian nephritis virus (G-4260 strain) in inoculated laying hens.

Specific-pathogen-free laying hens were inoculated intravenously with the G-4260 strain of avian nephritis virus (ANV). The distribution of the virus in organs, histological changes in main organs, the condition of laying, and egg transmission of the virus were examined in them. Over an experimental period of 27 days, no clinical sings were observed. In a chronological study on the distribution of the virus in organs, the virus was recovered from liver, kidney, jejunum, and rectum for 6 days postinoculation (PI). The virus titer in organ emulsion was the highest in the jejunum of all the main organs. The virus was recovered from the kidney for 8 days PI, although it was not so high in this organ. It was not recovered from the ovary or oviduct. Fluorescent antigens were not observed at all in any material. In a pathological examination, some local inflammatory changes were observed only in the kidney. There were no significant changes in the ovary, oviduct, or any other organ. Antibody appeared 10 days PI and was detectable even 27 days PI, although it was not so high in titer. There was no significant difference in the rate of egg-production between the infected and the sham inoculated groups. No virus was isolated from 111 fertile eggs laid by infected hens over a period from 2 to 27 days PI.