The frequency and magnitude of outbreaks of arthropod-borne viruses (arbovirus), particularly those transmitted by Aedes mosquitoes, are increasing globally, fuelled by the convergence of ecologic, economic and social factors. These factors include rapid urbanization, migration, climate change, insecticide resistance, poverty, and water and sanitation deficiencies. Some Aedes spp. mosquitoes (Aedes aegypti and Aedes albopictus) have adapted to feeding on humans and reproducing in water collections near human habitats, particularly under favourable tropical and subtropical temperatures. Thus, continuing urbanization and climate change are driving the expansion of the geographic range in which these vectors can thrive. Vulnerable populations in tropical and sub-tropical regions are typically most exposed, and many are threatened by circulation of multiple arboviruses including dengue, chikungunya, Zika and yellow fever viruses, among others.  

The World Health Organization is poised to launch a Global Arbovirus Initiative, focusing initially on Aedes-borne arboviral diseases, that will strengthen the coordination, communication, capacity-building, research, preparedness and response necessary to mitigate the growing risk of epidemics due to arboviral diseases. The initiative is being proposed as a collaborative effort between the World Health Emergencies Programme, the Department of Control of Neglected Tropical Diseases, and the Immunization, Vaccines and Biologicals Department.