BOTTOM LINE: Best treatment in lab is a water filter. On the trail in “real life” -- most everyone gets sick sooner or later. ;-) Want the facts? Here:
Hiker water
treatment studies:
IN THE LAB (Ongerth, J. E. et. al "Backcountry Water Treatment to Prevent Giardiasis" American Journal of public health, Dec. 1989)
Iodine, 8 hours 99.9% effective
Iodine, 30 minutes 90% effective
Best filters(new) 100% effective
Filters after 88 liters 75% effective
Chlorine 85-90% effective
Heating 60 degrees C 10 min 96%
Heating 70 degrees C 10 min. 100%
IN REAL LIFE (AT thru hikers; 1994 Roland Mueser Long Distance Hiking, (
Purification method -- % illness in 5-6 months -- % Giardia only
Iodine --26% became ill, 6% Giardia
Filtering--30% became ill, 9% Giardia
Boiling--34% became ill, 3% Giardia
Chlorine--75% became ill, 0% Giardia
No treatment --27% became ill, 3% Giardia