What are vector-borne diseases ?

Many infectious disease agents are transmitted to humans or animals by blood-feeding insects or ticks, termed disease vectors. Vector-borne diseases pose an enormous public health burden, causing an estimated 700,000 deaths per year worldwide. Mosquitoes are the most important vectors of human disease, transmitting many different parasitic and viral pathogens including those that cause malaria, filariasis, dengue, chikungunya, Zika, and yellow fever.

For more information:
https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases