Cryptic connections illuminate pathogen transmission within community networks.

Area of Science:

• Ecology
• Epidemiology
• Conservation Biology

Background:

• Pathogen transmission is fundamental to epidemic prediction and control.
• While within-group transmission is well-studied, inter-group and inter-species connections remain poorly understood.
• These 'cryptic connections' can be vital for large-scale outbreaks across populations and species.

Purpose of the Study:

• To quantify the importance of cryptic connections in disease dynamics.
• To compare transmission routes derived from direct contact and social groups versus those revealed by surrogate pathogens.
• To assess the role of cryptic connections in the spread of white-nose syndrome in bats.

Main Methods:

• Characterized social networks in eight bat communities.
• Traced transmission dynamics of surrogate-pathogen epidemics.
• Compared epidemiological data with bat social structures and white-nose syndrome spread.

Main Results:

• Cryptic connections increased links between individuals and species by an order of magnitude.
• Surrogate pathogen dynamics revealed individuals connected to ~15% of the population, including solitarily roosting bats and other species.
• Cryptic connections explained three times more variation in white-nose syndrome transmission than group-based connections.

Conclusions:

• Cryptic connections are critical for understanding pathogen spread, significantly expanding transmission networks.
• These hidden links facilitate community-wide pathogen dissemination and can lead to explosive epidemics.
• The findings highlight the need to incorporate cryptic connections into disease management strategies, particularly for wildlife diseases like white-nose syndrome.