Total confirmed malaria cases by origin and vector control interventions. Panel A shows total confirmed malaria cases by origin between 2001 and 2012. Panel B shows households protected by indoor residual spraying (IRS) and long lasting insecticidal nets (LLINs) distributed between 2004 and 2012. In high-risk foci not covered by LLINs, IRS is done twice a year. The first round of IRS is undertaken during pre-monsoon (April-May) and the second round in monsoon (July-August) each year.