Serologic detection of adenovirus infections in specific-pathogen-free chickens.

A specific-pathogen-free flock of White Leghorns, which were housed conventionally and were previously serologically negative for all common poultry pathogens including avian adenoviruses, incurred an outbreak of adenovirus that was detected at about 39 weeks of age. The infection was detected serologically through the agar-gel precipitin test (AGPT) and also by a microneutralization test (MNT) adapted for 11 serotypes of avian adenovirus. The MNT detected specific antibodies to serotype-3 avian adenovirus (IBHV-Tipton) but no other serotype. While AGPT-positive sera drawn from the flock gradually declined from 54% to 17%, neutralizing-antibody levels rose sharply at 46 weeks of age to a peak that was maintained over the remaining 18 weeks of the flock's production.