Sawyer water filters use Hollow Fiber Membranes, a technology developed for kidney dialysis.
The pointONE Filter’s™ pores are so small (0.1 micron absolute) that no harmful bacteria including those which cause Cholera , Typhoid and E. Coli, protozoa, or cysts can get through.
The filter attains the highest level of filtration available today exceeding US EPA standards for drinking water

Water borne diseases liked typhoid, dysentery, cholera are common in Liberia especially in the rural and remote parts where people are still drinking from open wells, hand pumped, wells, streams and ponds.