Bill and Melinda Gates to divorce after 27 years

Bill and Melinda Gates have announced their separation in a tweet saying "we no longer believe we can grow together as a couple".

The billionaire couple have three children and jointly run the Bill & Melinda Gates Foundation.

The organisation has spent billions fighting causes such as infectious diseases and encouraging vaccinations in children. So what will this mean for their philanthropic work?

David Callahan is the founder of the Inside Philanthropy News website and author of The Givers.

"This is not a small family foundation that is going to fall apart... This is the biggest private foundation in the world but they built this from the ground up over the last 20 years. They share a deep commitment to it. It's unlikely that either one of them would be happy to see it not continue to do the work that it does."

(Photo: Bill and Melinda Gates. Credit: EPA)