Drugs for Vector-Borne Protozoal Diseases in a One Health Scenario. A European Perspective.

Vector-borne protozoal diseases (VBPD) represent an enormous health and economic burden, particularly in low- and middle-income countries. Their control requires integrated approaches that consider not only therapeutic interventions for affected human and animal populations but also preventive tools. Environmental contamination can lead to therapeutic ineffectiveness. Effective intervention must consider in-depth knowledge of the environmental factors that regulate the exposure, transmission and pathogenicity of VBPD within a One Health approach. In recent decades, the incidence and prevalence of VBPD have been substantially reduced in many regions of the world, although there are still hot spots and emerging epidemiological cycles. Except for a partially protective vaccine against malaria, vaccination is not available for any other human VBPD, and therefore epidemiological control and chemotherapy are the main control tools. Current therapeutics have several drawbacks, including reduced efficacy, toxicity and high price of safer formulations. In addition, the industrial pipeline is limited, and no therapeutic breakthroughs are expected. Integrated control of VBPD requires multitarget control systems adapted to the disease and region. In this scenario, harmonized surveillance systems, accurate reporting and increased public and private investment will ensure more rational use of the few available and new drugs.