It kills a child under 5 every minute on average.

Diarrheal disease, the second leading cause of death for children globally, could become even more difficult to control as poor urban areas with limited clean water access expand.

An international team of researchers led by a Stanford epidemiologist finds reason for hope in a low-cost water treatment device that reduces rates of diarrhea in children, provides good-tasting water and avoids the need for in-home treatment - improvements over other purification strategies that could significantly increase uptake.

Their results were published Aug. 8 in The Lancet Global Health.

Even if it is safe at the source, water in these systems is at risk of becoming contaminated while sitting in pipes.

"Group level water treatment among people who share a water supply removes the individual burden on households to treat their own water," said study senior author Stephen Luby, a professor of medicine in the Division of Infectious Diseases and Geographic Medicine at the Stanford School of Medicine.