Fig. 3.
Effect of drugs with different levels of transmission-blocking activity on reductions in clinical malaria. Relative reduction in clinical incidence among children under 5 years due to case management (a–c) or MDA (d–f) with drugs of increasing transmission-blocking activity (x-axis). Low, medium, and high endemicity levels (columns) are indicated by slide prevalence among 2–10 year old children (PR2–10). The simulated drugs are short-lived (allowing re-infection after 3 days) but exhibit transmission-blocking activity comparable to sulfadoxine-pyrimethamine (SP), artemisinin combination therapies (ACT), or ACT + primaquine (100%). Case management (a–c): coverage levels (40, 60, 80, 100%) indicate the proportion of malarial fever cases treated, and impact shown is in the absence of MDA. MDA (d–f): the steady-state transmission reductions are the result of long-term, sustained MDA to a randomly chosen 80% of the population 2, 4, or 6 times a year, in the absence of any case management