Longitudinal field studies of infectious bronchitis virus and avian pneumovirus in broilers using type-specific polymerase chain reactions

In longitudinal studies, 13 flocks were swabbed twice each week for the life of the flock (up to 46 days). The swabs were analyzed by type-specific reverse transcriptase polymerase chain reactions. Massachusetts type vaccinal infectious bronchitis virus (IBVs), applied at the hatchery, were usually maximal during the first week, as expected and, notably, remained detectable for 3 to 4 weeks, occasionally longer. IBV of the 793/B type (also known...