Vector-borne infections in the tropics and health policy issues in the twenty-first century

Over the past 2 decades scientific advances and evolving strategies have si gnificantly contributed to improved tools for control of vector-borne infec tions. These are: diagnostics-rapid assessment methods, non-invasive or minimally so yet sens itive and specific; new chemotherapeutics; pyrethroid insecticides and biological insecticidal products; refined strategies, such as combination therapy, rotation of insecticides f or resistance management, community-directed treatment, standardized monito ring and evaluation to define programme progress; better epidemiological knowledge through improved identification of parasit es and vectors; GIS, remote sensing and climate models which provide tools for epidemic pre diction, planning control programmes and permit effective policy analysis; greater involvement of NGDOs (non-governmental development organizations) a nd CSOs (civil society organizations) in control; advent of donation programmes which involve community-based or directed mas s drug distribution. Future problems could be: (1) the over-emphasis on inflexible financing by the insistence of donors o n SWAps (sector-wide investment), (2) the over-reliance on pyrethroid pesticides, (3) the over-expectation that basic research will provide new drugs and vac cines for resource-poor settings in the necessary time scales, and (4) the failure to recognize that biological processes have an inherent cap acity for change which outstrips the capacity of health services to respond . Malaria is a paradigm of an 'emerging disease'. (5) The challenge of implementing a 'vertical' approach to disease control within national health programmes, in the face of significant donor opposit ion to such programmes is a challenge even when such approaches will secure a 'public good'.