Key dates in the latest Ebola epidemic, the worst ever outbreak of the haemorrhagic fever which first surfaced in 1976 in what is now the Democratic Republic of Congo.

According to the latest toll given by the World Health Organization (WHO), the epidemic has left 11,300 dead, mainly in the west African states of Guinea, Liberia and Sierra Leone, out of almost 29,000 cases.

- Epidemic starts in Guinea -

- December 6, 2013: A two-year-old child dies in southern Guinea and is later identified as "patient zero". The virus remains localised until February 2014, when a careworker in a neighbouring province dies.

- Ebola begins to spread -

- On March 31, 2014 two cases are confirmed by the WHO in Liberia, while on May 26 Sierra Leone confirms its first case, to be followed in late July by Nigeria, in August by Senegal and in October by Mali. Senegal and Nigeria are declared free of Ebola in October 2014 while Mali is declared Ebola-free in January 2015.

- May 30, 2014: Ebola is "out of control", according to the aid group Doctors Without Borders (MSF). The three worst-hit countries, Guinea, Sierra Leone and Liberia, declare measures including states of emergency and quarantines. Many neighbouring nations close their borders with the affected countries.

- A 'public health emergency' -

- August 8, 2014: The WHO declares Ebola a "public health emergency of international concern". Four days later it authorises the use of experimental drugs to fight Ebola after an ethical debate. That day, a Spanish missionary infected in Liberia dies in Madrid, the first European fatality.

- Death in the US -

- September 30, 2014: A Liberian man is hospitalised in the US state of Texas, the first Ebola infection diagnosed outside Africa. He dies on October 8.

October 6, 2014: A Spanish nurse in a Madrid hospital becomes the first person to be infected outside Africa. She is treated and given the all-clear on October 19.

- Ebola begins a halting retreat -

- February 22, 2015: Liberia says it is lifting nationwide curfews and re-opening borders, as the epidemic begins to retreat.

- February 26, 2015: The US ends its military mission in west Africa where it had deployed 2,800 soldiers to help in the fight against Ebola, mainly in Liberia.

- May 9, 2015: Liberia is declared Ebola-free by the WHO after no new cases were recorded for 42 days.

- Surge in Guinea and Sierra Leone -

- May 20, 2015: The WHO reports a spike in new cases in Guinea and in Sierra Leone. Guinea extends its health emergency on June 6.

- June 12, 2015: Sierra Leone reimposes a three-week curfew. The capital Freetown suffers a fresh outbreak in mid-June.

- June 30, 2015: Liberia says Ebola has returned there too.

- Closing in on a vaccine -

- July 10, 2015: International donors pledge $3.4 billion to help stamp out Ebola.

- July 31, 2015: The WHO says that an Ebola vaccine provided 100-percent protection in a field trial in Guinea, suggesting the world is "on the verge of an effective Ebola vaccine".

- Hardest-hit countries emerge from the epidemic -

- November 7, 2015: Sierra Leone is declared free of the outbreak by the WHO.

- November 17, 2015: The last known Ebola case in Guinea, a three-week-old girl, is declared recovered from the virus.

- December 4, 2015: Liberia releases from hospital its last two known Ebola cases.