Shedding of Chlamydia psittaci in birds is exacerbated by which factor?

• A. Vaccination
• B. Stress
• C. Temperature stability
• D. Adequate nutrition

Answer: (B)

Stress drives increased shedding of Chlamydia psittaci in birds. When birds face stress from overcrowding, transport, handling, poor husbandry, or illness, their immune defenses wane. This immunosuppression can reactivate latent infections and allow the bacterium to replicate more and produce more infectious elementary bodies that are shed in feces, nasal secretions, and ocular discharges. The result is greater environmental contamination and a higher chance of transmission. Vaccination helps prevent disease but doesn’t inherently increase shedding; good nutrition supports immune function and tends to reduce shedding, while temperature stability mainly affects how long shed organisms survive outside the host rather than how much the host sheds.