Karen Grepin, assistant professor of global health policy at New York University’s Robert F. Wagner Graduate School of Public Service, describes the March issue of BMJ’s Sexually Transmitted Infections in this post in her “Global Health Blog.” The issue, edited by Alan Whiteside, Gary Brook, Till Bärnighausen, John Imrie and William Wong, is “devoted to the topic of HIV and health systems,” she writes, noting, “The articles in this issue are all devoted to challenges facing the global response from the perspective of health systems as it enters into this new phase of the response” (2/17).