Ebola - Liberia's chief medical officer, Dr Berenice Dahn, is in voluntary quarantine at home
Of the four west African nations affected by the ebola outbreak, it's Liberia that's been hit the hardest. There, some three and a half thousand people have been infected - and of those, over one thousand eight hundred have died, according to the World Health Organisation. Promises of aid have poured in, and some of it is beginning to arrive at last. But hospitals and doctors in Liberia are still struggling to cope - and at the moment, Liberia's chief medical officer, Dr Berenice Dahn, is in voluntary quarantine at home - after her assistant died of the disease. Caroline Wyatt asked her what had led to her decision to put herself into quarantine.