Updated September 2021. Provision of water and sanitation and good hygiene practices play an essential role in protecting human health during all disease outbreaks, including during Ebola Virus Disease (EVD) outbreaks. This question and answer document provides practical, evidence-based recommendations on minimum requirements and best practices for water, sanitation, hygiene (WASH). It was originally developed in 2014 during the West Africa Ebola Outbreak and has been updated in 2021 to reflect lessons learned and new operational research data. The key recommendations on WASH remain the same.