"The outbreak… ended today with no new cases reported over the past 42 days after the last patient was discharged from treatment," the UN World Health Organization (WHO) said.

The highly infectious disease is similar to Ebola, but there are no vaccines or anti-viral treatments approved to treat the virus. It has a fatality rate of up to 88%, according to the WHO.

It is transmitted to people from fruit bats and spreads among humans through direct contact with the bodily fluids of infected people, surfaces and materials.

The true death toll from the outbreak is likely to have been higher than the 12 officially recorded, because 23 people who came into contact with victims died without being tested - and it is too dangerous to do post-mortems.

The four patients who recovered from the disease have been enrolled in a survivors- programme. They are receiving psychosocial and other post-recovery support measures.

It was Equatorial Guinea's first-ever outbreak of the disease, affecting four of its eight provinces