Discussion
infection
INFECTION
Following interest in the potential of chemoprevention as a control tool [Within the limitations of the quasi-experimental design and the single large cluster used per arm, this study demonstrates a significant, surprising advantage for co-timed MDA and IRS over IRS alone, and strongly suggests that further investigation should be pursued. Visual inspection of measured qPCR results over all 6 surveys, depicted in Fig. Geostatistical modeling analysis using all qPCR data from all six cross-sectional surveys and an intention to treat approach showed that, over the 32 months of the study after baseline, residents of the IRS arm were Secondary DiD analysis, also intention to treat, compared single prevalence survey timepoints to baseline, and confirmed the significant protective impact of MDA+IRS over IRS alone (Fig. It’s striking that survey data, measured 5–7 months after a single treatment round of MDA in this high transmission environment, still show significant protective advantage from MDA + IRS over IRS. However, cross-sectional measurements of prevalence would almost certainly be lower and even more differentiated at points in time closer to the MDA round. High-coverage MDA immediately lowers population prevalence which then slowly rebounds, as chemoprophylaxis expires and re-infection occurs. Under the assumption of ideal DP protection and compliance with medication regimen, in the first month after the intervention, Sustainability is often a concern for MDA in a control context, but absent a change to the underlying forces of infection, resurgence will reliably occur when any control intervention ceases [Because prevalence in most of the surveys was measured at 5–7 months after the MDA, the deepest impacts of MDA almost certainly occurred outside the survey observation window. Health facility catchment areas are not constrained, so it is difficult to reliably quantify this effect through facility based case surveillance trends. Monthly cross-sectional surveys following an MDA + IRS and an IRS intervention, or a cohort study of incidence following the interventions, could help capture the full protective impact of MDA+IRS. As IRS costs much more than MDA per person, the addition of MDA to IRS is likely to be cost effective, especially as the benefits of the combination are expected to include reduction of clinical cases in the first months after the joint round.