Avian nephritis virus infection of chicks: virology, pathology, and serology.

Avian nephritis virus (ANV), G-4260 strain, was inoculated orally into 1-day-old specific-pathogen-free chicks of the line 15I for virological, pathological, and serological study of the ANV infection of chicks. The virus titer and incidence of appearance of fluorescent antigens in the kidneys were highest at 4 days postinoculation (PI) and decreased gradually. The degeneration of proximal tubules was the principal pathological change in kidneys of chicks at 4 days PI, and interstitial nephritis was the principal pathological change in kidneys of chicks from 6 to 14 days PI. Moreover, gouty nodules were apparent in the kidneys of more than half of the chicks at 10 days PI. The plasma urate value of infected chicks was clearly higher than that of control chicks, reaching a maximum at 10 days PI, then gradually decreasing. The serum antibody was detected from 4 days PI and increased gradually. The chicks affected with visceral urate deposits or urate deposits in the digitated joints showed high plasma urate values (more than 100 mg/dl).