[Serological studies in bovine Q fever]

Area of Science:

• Veterinary Immunology
• Rickettsial Disease Diagnostics
• Bovine Reproductive Health

Background:

• Reproductive diseases like abortion, retained placentae, and endometritis are significant concerns in cattle herds.
• Serological tests are crucial for diagnosing infectious causes of these conditions.
• Rickettsial infections can contribute to bovine reproductive pathologies.

Purpose of the Study:

• To compare the efficacy of complement-fixation test (CFT) and immunofluorescence titration method (ITM) for detecting rickettsial antibodies in cattle.
• To evaluate the diagnostic agreement between CFT and ITM in a field study.
• To investigate the dynamics of antibody response following experimental and spontaneous rickettsial infections.

Main Methods:

• Serological analysis of 1250 cattle blood samples from 13 farms using CFT and ITM.
• Experimental infection of two cows with rickettsiae to monitor antibody development.
• Observation of antibody titers in spontaneously infected cows with a history of miscarriage.

Main Results:

• Of the positive sera, 52.3% were positive by both CFT and ITM, 28.6% by CFT only, and 19% by ITM only.
• Complement-fixing antibodies appeared 8 hours to 15 days post-infection in experimentally infected cows, persisting up to 160 days with titers up to 1:160.
• In naturally infected cows, antibody titers ranged from 1:10 to 1:40 and persisted for six months.

Conclusions:

• CFT and ITM show moderate agreement in detecting rickettsial antibodies in cattle.
• Antibody response dynamics vary between experimental and natural infections.
• Serological monitoring is essential for understanding the role of rickettsiae in bovine reproductive disorders.