Mixed effects models for PCR-detected infection.

Model 1: Allowing for random variation between villages and between households; no covariates.Model 2a: Model 1 plus adjusting for individual effects (age and sex).Model 2b: Model 1 plus adjusting for village effects (elevation above sea level, mean wet season NDVI and mean dry season NDVI).Model 3: Model 2 plus adjusting for all covariates.Estimates of variation between villages and between households (��2?variance of log odds of infection between units, OR75-25?odds ratio between units at the 75th and 25th percentiles of distribution) and odds ratios associated with sex, age, elevation above sea level, mean dry NDVI and mean wet NDVI (with 95% confidence intervals) under alternative models. P values less than 0.05 are in bold.