Age-specific infectious period shapes dynamics of pneumonia in bighorn sheep

Area of Science:

• Veterinary Medicine
• Wildlife Ecology
• Genetics

Background:

• Superspreading significantly impacts disease dynamics, often driven by variations in individual contacts, infectiousness, or infectious periods.
• While contact and infectiousness variations are well-studied, the role of infectious period variation in disease spread remains underexplored.
• Infectious period variation is a critical factor in managing diseases affecting public health, livestock, and wildlife conservation.

Discussion:

• This study provides rare evidence of infectious period variation contributing to superspreading in a wild animal population.
• Persistent Mycoplasma ovipneumoniae infections were identified in older bighorn sheep homozygous at a key immune gene locus.
• These findings suggest that age structure, host genetics, and prolonged infectious periods interact to influence disease transmission.

Key Insights:

• Older bighorn sheep with specific genetic profiles can act as persistent reservoirs for Mycoplasma ovipneumoniae, facilitating superspreading events.
• Genetic homozygosity at an immunologically relevant locus is associated with prolonged infections and increased disease transmission potential.
• The interplay between host age, genetic makeup, and infectious period duration is a crucial determinant of disease spread and severity.

Outlook:

• Understanding these complex interactions is vital for predicting population-level responses to infection, ranging from recovery to severe decline.
• Further research into host genetics and prolonged infectious periods can improve disease management strategies in wildlife populations.
• This work underscores the importance of considering individual variation in infectiousness for effective disease control and conservation efforts.