Measles in the tropics and public health practice.

Measles shows three distinct transmission patterns in the tropics, one each in urban, rural and insular or very remote areas. The characteristics of measles transmission are reviewed for each area, both with and without immunization. Planning must be based on the best use of currently underused infrastructure in the light of epidemiology. Mass mobile campaigns are not advised for urban areas. Vaccination of the sick and the well as part of episodic medical care is proposed, and vaccination of the sick is supported as safe and effective. Age floors and ceilings should be set with reference to the local situation; adoption of international "rules of thumb", without reference to local conditions, is inadvisable." A mixed strategy is urged for rural areas, with routine immunization against measles as part of a multi-antigen programme. Routine immunization should be complemented by annual surveillance and containment during the seasonal trough. Research and development needs in measles control include better understanding of measles epidemiology, more operationally useful quantitative models, and trials of new control strategies. Control, elimination and eradication are defined and discussed.