Figure 4.

Local cluster maps of human biting rate and house type in 86 households in Nagongera, Uganda, before and after the introduction of indoor residual spraying

Houses were classified as modern (cement, wood, or metal walls, a tiled or metal roof, and closed eaves) or traditional (all other houses). Positive spatial autocorrelation (spatial clustering) occurs when a household with a specific outcome value is surrounded by neighbouring households with similar outcome value (low–low, high–high). (A) Human biting rate before indoor residual spraying (Oct 1, 2011, to Jan 31, 2015). (B) Univariate local indicator of spatial association (LISA) analysis of house type and human biting rate before indoor residual spraying. (C) Human biting rate after indoor residual spraying (Feb 1, 2015, to June 30, 2017). (D) Univariate LISA analysis of house type and human biting rate after indoor residual spraying. The implementation of indoor residual spraying was associated with study-wide declines in human biting rate. Before and after indoor residual spraying, a cluster of modern housing and low human biting rate is observed in the southeast of the study area. After indoor residual spraying, a cluster of traditional housing and high human biting rate is observed in the southwest of the study area.