A severe household water shortage facing two out of five people in the world is undermining efforts to contain the coronavirus pandemic.

Frequent and thorough hand washing is among the most effective measures in restricting the spread of the virus because the primary routes of transmission are droplets and direct contact, according to the World Health Organization. Yet, some 3 billion people don’t have access to running water and soap at home, and 4 billion suffer from severe water scarcity for at least one month a year, the United Nations group UN-Water said.

"It is a disastrous situation for people living without access to safe water and safely managed sanitation,” UN-Water Chair Gilbert F. Houngbo said in an interview. "The chronic underinvestment has left billions vulnerable and we are now seeing the consequences.”