Age-dependent patterns of bovine tuberculosis in cattle

Area of Science:

• Veterinary Epidemiology
• Infectious Disease Modeling
• Animal Health Economics

Background:

• Bovine tuberculosis (BTB) poses a significant threat to global cattle industries.
• Understanding age-specific infection risks is crucial for effective BTB control in cattle, but data has been limited.
• Previous studies have not adequately quantified age-dependent risks in cattle populations.

Purpose of the Study:

• To estimate age-specific bovine tuberculosis reactor rates in Great Britain.
• To identify age groups with the highest infection risk and detection probability.
• To inform targeted control strategies for bovine tuberculosis.

Main Methods:

• Utilized herd-level testing data combined with spatial movement data from the Cattle Tracing System (CTS).
• Employed a catalytic model to analyze infection risk and detection probability across different age groups.
• Analyzed infection incidence and reproductive numbers between 2004 and 2009.

Main Results:

• BTB infection risk and detection probability show strong age dependencies, increasing with age.
• Age-specific incidence rose until 24-36 months, with the highest rates in cattle aged 12-36 months.
• Infection risks were similar for beef and dairy cattle under 24 months, but diverged significantly in older animals.

Conclusions:

• BTB rates exhibit a consistent age-related pattern across diverse cattle populations.
• Targeting cattle aged 12-36 months in mass control programs may offer a beneficial strategy for BTB management.
• The findings provide practical insights into BTB epidemiology and effective control measures.