front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |review

WATER TURBIDITY AND DISEASE LEVELS.
LEGEND:
Water turbidity (black line) is measured in Nephelometric turbidity units.
Disease levels are presented as number of cases per day: Lab. Survey =blue line; Telephonic survey = pink line).
The Southern water plant was closed on april 8, 1993.
Data derived from MacKenzie et al., 1994. New Engl. J. Med., 331: 161-167

DRAWN YOUR CONCLUSIONS
There is an apparent delay between increase in water turbidity and the apparition of infected people.
If water transit time is considered negligible, we can estimate a five days’ incubation time for the disease