The spread of infectious diseases in migration routes between caravans and resident communities: Modelling yellow fever in Central America

Introduction

Climate-sensitive diseases are significantly affected by weather patterns and the social consequences of a changing climate. In this context, epidemics and human mobility can interact, leading to unpredictable impacts on both human and planetary health.

Methods

To investigate the impact of yellow fever (YF) vaccination in the context of an outbreak and its association with migration, we use a SEIRV-SEI compartmental deterministic model for humans and vectors and numerical simulations applied to three coupled populations - caravans, endemic and disease-free communities. Two scenarios are evaluated with different vaccination coverage levels at endemic communities and in caravans.

Results

When communities endemic to YF are the source of migration, herd immunity is critical, but vaccinating caravans is by far the most significant intervention to protect migrants and disease-free communities upwards from the risk of YF introduction.

Conclusion

Preventing outbreaks of climate-sensitive infectious diseases in the context of migration must be a joint effort of common interest. Maintaining vaccination coverage at recommended levels combined with the continued effort to vaccinate people on the move is the only intervention that can prevent a health crisis. Therefore, vaccination against climate-sensitive diseases should be considered climate adaptation.