Vector-borne diseases are a major health threat globally. They infect more than one billion people a year and cause more than one million deaths. People’s lives are disrupted economically and physically through loss of earnings, debilitation and disfigurement and many more family members are affected by reduced income and the need to provide care. The vast majority of people affected are in low-income countries, in conditions of poor housing and sanitation. In most countries it is the poor and marginalised that have not only the highest risks of catching vector-borne diseases but also have the least access to services for prevention, diagnosis and treatment. With the combination of climate change, increasing globalisation, international travel and transport of goods, disease vectors have moved across boundaries into new territories. In addition, diseases once thought to be restricted to certain areas are appearing in the same vectors in new areas.