Mobility and COVID-19 in Andorra: Country-Scale Analysis of High-Resolution Mobility Patterns and Infection Spread

Area of Science:

• Epidemiology
• Public Health
• Data Science

Background:

• Nonpharmaceutical interventions like mobility restrictions were crucial during the COVID-19 pandemic.
• The social and economic costs of these measures are high, and their comparative effectiveness is not well understood.
• Previous studies utilized limited population data from telecoms sources to assess behavioral changes and infection spread.

Purpose of the Study:

• To analyze the relationship between mobility patterns and COVID-19 transmission in Andorra.
• To evaluate the effectiveness of different types of mobility restrictions using comprehensive datasets.

Main Methods:

• Utilized comprehensive spatio-temporal telecoms data covering all mobile subscribers in Andorra.
• Integrated serology screening results (91% of the population) and COVID-19 case reports.
• Developed mobility metrics including country entrances, tourist contact, stay-at-home rates, trip-making, and crowding levels.

Main Results:

• Mobility metrics significantly decreased during lockdown and increased as restrictions eased.
• Several mobility metrics showed strong correlations with lagged COVID-19 transmission rates.
• Indoor crowding and inter-community trip-making metrics correlated more strongly with transmission than total trips or stay-at-home rates.

Conclusions:

• Mobility restrictions significantly influenced COVID-19 transmission dynamics.
• Policies targeting indoor crowding and inter-community travel may be more effective than broad mobility limitations.
• Findings support nuanced public health strategies that balance infection control with socio-economic considerations.