LLINEUP trial is a large-scale trial of next generation PBO bed-nets covering 104 health sub-districts in Uganda – approximately half of the area of the country. The primary outcome of the trial is malaria parasite prevalence in children <10 years old with anopheles vector density as a secondary outcome. Data are collected by cross sectional surveys at baseline and 6,12,18 and 25 months post net distribution. To date (data to 18 months) we have observed significant reductions in parasite prevalence (prevalence ratio [PR] adjusted for baseline at month 18 = 0·84, 95% CI 0·72–0·98; p=0·029) and in mean Anopheles gambiae s.s densities (density ration adjusted for baseline at month 18 = 0·25 (0·18–0·35) p<0·0001) in clusters receiving the next generation/PBO LLINs.
Anopheles gambiae was the primary vector at the inception of the project but we have significant declines in both An. gambiae and An. funestus and in many HSDs An. arabiensis is likely the vector responsible for residual transmission. DNA extracted specimens are available for all five time points. Mosquitoes were collected from a subset (20%) of the households where epidemiological surveys were conducted.
These paired data are a unique resource as they will permit 1. the simultaneous analysis of the differential impacts of transmission reducing interventions on parasite and vector genomic diversity 2. direct linkage of genomic signals of intervention impact to epidemiological and entomological effects which will be crucial for the development of genomic monitoring strategies 3. descriptions of parasite and vector population genetic structuring at varying hierarchical levels from micro to macrogeographic.
Martin Donnelly Liverpool School of Tropical Medicine (LSTM), UK