Fig. 1

Study districts. Overview of the study area, which covers the followed districts: a Chorrillos, 112 contacts identified (11.5%); b San Juan de Miraflores, 266 contacts identified (27.2%); c Villa El Salvador, 349 contacts identified (35.7%); d Villa María del Triunfo, 237 contacts identified (24.3%); e Surco, 5 contacts identified (0.5%); f Pachacamac, 8 contacts identified (0.8%)