The contribution of mass drug administration to global health: past, present and future.

Mass drug administration (MDA) is a means of delivering safe and inexpensive essential medicines based on the principles of preventive chemotherapy, where populations or sub-populations are offered treatment without individual diagnosis. High-coverage MDA in endemic areas aims to prevent and alleviate symptoms and morbidity on the one hand and can reduce transmission on the other, together improving global health. MDA is the recommended strategy of the World Health Organisation to control or eliminate several neglected tropical diseases (NTDs). More than 700 million people now receive these essential NTD medicines annually. The combined cost of integrated NTD MDA has been calculated to be in the order of $0.50 per person per year. Activities have recently been expanded due, in part, to the proposed attempt to eliminate certain NTDs in the coming two decades. More than 1.9 billion people need to receive MDA annually across several years if these targets are to be met. Such extensive coverage will require additional avenues of financial support, expanded monitoring and evaluation focusing on impact and drug efficacy, as well as new diagnostic tools and social science strategies to encourage adherence. MDA is a means to help reduce the burden of disease, and hence poverty, among the poorest sector of populations. It has already made significant improvements to global health and productivity and has the potential for further successes, particularly where incorporated into sanitation and education programmes. However logistical, financial and biological challenges remain.