Impact of population based indoor residual spraying with and without mass drug administration with dihydroartemisinin-piperaquine on malaria prevalence in a high transmission setting: a quasi-experimental controlled before-and-after trial in northeastern Uganda.

BACKGROUND: Declines in malaria burden in Uganda have slowed. Modelling predicts that indoor residual spraying (IRS) and mass drug administration (MDA), when co-timed, have synergistic impact. This study investigated additional protective impact of population-based MDA on malaria prevalence, if any, when added to IRS, as compared with IRS alone and with standard of care (SOC). METHODS: The 32-month quasi-experimental controlled before-and-after trial enrolled an open cohort of residents (46,765 individuals, 1st enumeration and 52,133, 4th enumeration) of Katakwi District in northeastern Uganda. Consented participants were assigned to three arms based on residential subcounty at study start: MDA+IRS, IRS, SOC. IRS with pirimiphos methyl and MDA with dihydroartemisinin- piperaquine were delivered in 4 co-timed campaign-style rounds 8 months apart. The primary endpoint was population prevalence of malaria, estimated by 6 cross-sectional surveys, starting at baseline and preceding each subsequent round. RESULTS: Comparing malaria prevalence in MDA+IRS and IRS only arms over all 6 surveys (intention-to-treat analysis), roughly every 6 months post-interventions, a geostatistical model found a significant additional 15.5% (95% confidence interval (CI): [13.7%, 17.5%], Z = 9.6, p = 5e-20) decrease in the adjusted odds ratio (aOR) due to MDA for all ages, a 13.3% reduction in under 5's (95% CI: [10.5%, 16.8%], Z = 4.02, p = 5e-5), and a 10.1% reduction in children 5-15 (95% CI: [8.5%, 11.8%], Z = 4.7, p = 2e-5). All ages residents of the MDA + IRS arm enjoyed an overall 80.1% reduction (95% CI: [80.0%, 83.0%], p = 0.0001) in odds of qPCR confirmed malaria compared with SOC residents. Secondary difference-in-difference analyses comparing surveys at different timepoints to baseline showed aOR (MDA + IRS vs IRS) of qPCR positivity between 0.28 and 0.66 (p < 0.001). Of three serious adverse events, one (nonfatal) was considered related to study medications. Limitations include the initial non-random assignment of study arms, the single large cluster per arm, and the lack of an MDA-only arm, considered to violate equipoise. CONCLUSIONS: Despite being assessed at long time points 5-7 months post-round, MDA plus IRS provided significant additional protection from malaria infection over IRS alone. Randomized trials of MDA in large areas undergoing IRS recommended as well as cohort studies of impact on incidence. TRIAL REGISTRATION: This trial was retrospectively registered 11/07/2018 with the Pan African Clinical Trials Registry (PACTR201807166695568).

Community facilitators and barriers to a successful implementation of mass drug administration and indoor residual spraying for malaria prevention in Uganda: a qualitative study.

BACKGROUND: There is growing interest to add mass drug administration (MDA) to the already existing malaria prevention strategies, such as indoor residual spraying (IRS). However, successful MDA and IRS requires high population-wide coverage, emphasizing the importance of community acceptance. This study's objectives were to identify community-level facilitators and barriers during the implementation of both MDA and IRS in communities with high malaria transmission intensity. METHODS: This was a qualitative study conducted in two sub-counties in Katakwi district. Kapujan sub-county residents received two rounds of IRS and MDA while Toroma sub-county residents received two rounds of IRS only. Key informant interviews and focus group discussions were conducted with key influential district and sub-county personnel and community members. Data were analysed using thematic analysis. Transcripts and interview notes from the in-depth interviews were analysed using a coding scheme developed from pre-defined topics together with themes emerging from the data. The Nvivo software program was used to aggregate the data by codes and to present study findings. RESULTS: Overall, 14 key informants were interviewed: 4 from Katakwi district and 5 each from Kapujan and Toroma sub-counties. Five focus group discussions were conducted: 4 with community members (men and women), 2 in each sub-county and one with medical staff of Toroma health centre IV. Important themes for consideration raised by the respondents include community sensitization, conducting implementation during the low activity dry season, involvement of government and local leadership, use of the competent locally composed team, community knowledge of malaria effects and consequences, combining interventions and evidence of malaria reduction from interventions. Potential barriers such as spreading of misinformation regarding interventions, the strong unpleasant smell from Actellic and inadequate duration of engagement with the community should be taken into consideration. CONCLUSION: This study documents important community engagement strategies that need to be considered when implementing malaria MDA in combination with IRS, for malaria prevention in such settings. This information is useful for malaria programmes, especially during the design and implementation of such community level interventions.