Classification trees representing the important risk factors for malaria prevalence.

<p>The high risk groups are displayed in red. In each node 0 stands for negative slide and 1 for positive slide. The following variables were selected by the tree as important risk factors: <i>Anopheles</i> density (Ano-density) with a cut off of 1.5 <i>Anopheles</i> per house; Survey number 1 to 11; Housing (1,2 = poorest housing condition and 3,4 highest housing condition); Age with a cut off of 38 years old.