Table 2: IBV isolates with their tissue tropism (according to the presence of IBV by diagnostic N gene RT-PCR) and clinical history.

IsolateTropismClinical findingsVaccine usedChicken/age

JOA4Trachea, ovaryDrop in egg productionH120
Watery cysts in ovariesM41Layer, 24 weeks
Short and enlarged oviducts4/91

JOA2Trachea, kidney, ovaryDrop in egg productionH120, M41, 4/91Layer, 22 weeks

Saudi-1TracheaRespiratory signsH120, 4/91Broiler, 22 days

Saudi-2TracheaRespiratory signsH120, 4/91Broiler, 24 days

Iraqi IBVTrachea, kidneyRespiratory signs, nephritis, and drop in egg productionH120, M41, 4/91Breeder, 25 weeks