Figure 2.

The prevalence of infection (with any Onchocerca volvulus larval stage) in Simulium ochraceum s.l. parous flies in localities I and II: A, before the arrival (April and October), B, during the stay (May through July and November through February), C, after departure (August and February) of temporary migrant workers in the coffee seasons of 1997–1998 and 1998–1999 in the Southern Chiapas onchocerciasis focus, Mexico. D compares localities I and II for all three periods combined; E and F compare, respectively within localities I and II, fly infection levels between the before, during, and after periods, and G compares the periods for both localities combined. Error bars denote 95% confidence intervals; ovals indicate statistical differences with associated p-values.