Fig. 4

HRP2 RDT sensitivity, slide positivity rate and rainfall by study site and month. Rainfall is plotted in millimeters per month on the left y axis. Sensitivity and slide positivity rate are plotted on the right y axis. The navy band represents the 95% confidence interval for sensitivity. The dashed line represents the slide positivity rate. There was significant variation in HRP2 RDT sensitivity across the study sites and a decline in RDT sensitivity was noted following a decline in malaria transmission. In Rukara, monthly estimates of HRP2 RDT sensitivity ranged from 90 to 97%. Conversely, in Kibirizi, a site subject to two rounds of IRS during the study period, the sensitivity of the HRP2 RDT declined from 88 to 67% as the slide positivity rate fell from 46 to 3%. SPR slide positivity rate; CI confidence interval