The death toll from Zambia's cholera outbreak has risen to almost 700, says the medical charity Médecins Sans Frontières (MSF).

It is the largest ever recorded in the country. It began in the capital, Lusaka, in October and has since spread to all of Zambia's provinces infecting more than 19,000 people.

MSF says cholera is easily treated - with rehydration, but without the proper care, a person can die in a few hours.

The disease is caused by contaminated water, so access to clean drinking water is vital to stop it spreading further.