Environmental changes such as deforestation and urbanization can disrupt ecosystems, bringing humans into closer contact with wildlife reservoirs. Global travel and trade facilitate the rapid spread of pathogens across borders. Microbial evolution and genetic mutations can lead to new strains of pathogens that can evade current immune responses. Antibiotic resistance allows previously manageable infections to become difficult to treat. Climate change can alter the habitats of vectors like mosquitoes, expanding the range of diseases such as dengue fever and Zika virus.
