Using quantitative polymerase chain reaction to correlate Chlamydia pecorum infectious load with ocular, urinary and reproductive tract disease in the koala (Phascolarctos cinereus).

Complex interactions between Chlamydia pecorum infection, the immune response and disease exist in the koala. We used quantitative polymerase chain reaction to investigate the relationship between C. pecorum infectious load and ocular and urogenital tract disease. Chlamydia pecorum shedding was generally higher in animals with chronic, active disease than in animals with inactive disease. The absence of ocular disease was generally associated with low levels of shedding, but relatively high levels of shedding in the urogenital tract were detected in some koalas without clinical disease signs. These results suggest a complex disease pathogenesis and clinical course in C. pecorum-infected koalas.