Infection intensity in relation to duration and frequency of water contact. Infection intensity (arithmetic mean EPG, both pre-control and one year after treatment) in relation to duration and frequency of water contact, for six demographic groups based on three age categories and both sexes. The durations are the accumulation over season, hour of the day, and type of activity of the values for each demographic group in Figure 3. Similarly, the frequencies are the accumulation of values in Figure 4. Black dots = males, red triangles = females; 1 = 0-9 years, 2 = 10-19 years, 3 = 20 years and above.