Epidemiological Dynamics in Populations Structured by Neighbourhoods and Households

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• Infectious disease spread is influenced by host population structure, including households and neighborhoods.
• The interplay between household and neighborhood structures in disease epidemiology is not well understood.

Purpose of the Study:

• To develop a multi-scale epidemic model exploring the epidemiological implications of spatially clustered households with similar demographic structures.
• To analyze how household size, within-household vs. outside-household transmission, and neighborhood transmission localization affect disease dynamics.

Main Methods:

• Development of a multi-scale epidemic model incorporating neighborhoods of households.
• Construction of the household reproduction number across neighborhoods.
• Derivation of the analytic probability of an outbreak from a single infected individual.

Main Results:

• Reduced localization of transmission within neighborhoods decreases the household reproduction number when household sizes vary.
• This effect is amplified by greater household size differences and transmission rate divergence.
• The impact of large household sizes on infection risk is largely confined to residents of those neighborhoods.

Conclusions:

• Household size information is often more critical for surveillance than neighborhood data.
• Neighborhood localization and household size influence the spatial progression of outbreaks.
• The spatial and demographic structure of host populations significantly shapes epidemiological dynamics.