This paper proposes an explanation concerning why some global health issues such as HIV/AIDS attract significant attention from international and national leaders, while other issues that also represent a high mortality and morbidity burden, such as pneumonia and malnutrition, remain neglected. The rise, persistence and decline of a global health issue may best be explained by the way in which its policy community -the network of individuals and organizations concerned with the problem -comes to understand and portray the issue and establishes institutions that can sustain this portrayal. This explanation emphasizes the power of ideas and challenges interpretations of issue ascendance and decline that place primary emphasis on material, objective factors such as mortality and morbidity levels and the existence of cost-effective interventions. This explanation has implications for our understanding of strategic public health communication. If ideas in the form of issue portrayals are central, strategic communication is far from a secondary public health activity: it is at the heart of what global health policy communities do.Une traduction en français de ce résumé figure à la fin de l'article. Al final del artículo se facilita una traducción al español. املقالة. لهذه الكامل النص نهاية يف الخالصة لهذه العربية الرتجمة