Ebola Outbreaks in West Africa, with Focus on the 2014–2016 Epidemic (1976–2016)

1. Ebola virus first identified in Zaire outbreak

   Sep 1, 1976Labels: Ebola virus, Yambuku, WHO investigation

   In 1976, a severe outbreak of hemorrhagic fever centered near Yambuku in northern Zaire (now the Democratic Republic of the Congo) led scientists to identify a previously unknown virus, later named Ebola. A WHO-led investigation documented widespread transmission linked to healthcare settings and unsafe injections. This discovery created the basic scientific and public-health framework used in later outbreaks, including in West Africa.

   • Bull WHO
   • Britannica

2. Guinea confirms Ebola as cause of epidemic

   Mar 23, 2014Labels: Guinea, Gueckedou, Ebola confirmation

   After unexplained illnesses and deaths in Guinea’s forest region, national authorities confirmed Ebola virus disease as the cause in March 2014. Early cases were concentrated in the southeast near Gueckedou and spread to other areas, including the capital, Conakry. This confirmation marked the start of the 2014–2016 West Africa epidemic as a recognized Ebola outbreak.

   • Al Jazeera
   • WHO DON

3. WHO reports rapid spread and health-worker infections

   Apr 25, 2014Labels: WHO situation, Guinea health, prefectures

   By late April 2014, WHO situation updates showed hundreds of clinical cases and many deaths in Guinea, with confirmed infections among healthcare workers. Reports described multiple affected prefectures and ongoing transmission, indicating that control measures were not yet stopping the outbreak. These early patterns—health facility spread, delayed detection, and wide geographic movement—shaped the escalating regional response.

   • WHO DON

4. Sierra Leone records its first Ebola case

   May 24, 2014Labels: Sierra Leone, cross-border transmission, rural districts

   Sierra Leone confirmed its first Ebola case in late May 2014, showing that the outbreak had crossed national borders through land travel and community links. The epidemic intensified as transmission expanded in both rural districts and major cities. This shift turned the event from a national emergency into a multi-country crisis requiring coordinated cross-border action.

   • WHO AFRO
   • Britannica

5. Ebola introduced into Nigeria via air travel

   Jul 20, 2014Labels: Nigeria, Lagos, imported case

   An infected traveler from Liberia arrived in Lagos in July 2014, leading to a small but dangerous chain of transmission in Nigeria’s largest city. Nigerian public-health teams used intensive contact tracing and isolation to limit spread. The episode demonstrated how quickly Ebola could travel internationally—and how rapid surveillance and response could contain it.

   • PAHO WHO
   • WHO AFRO

6. WHO declares Ebola a global health emergency (PHEIC)

   Aug 8, 2014Labels: WHO, PHEIC, International Health

   In August 2014, WHO declared the West Africa Ebola outbreak a Public Health Emergency of International Concern (PHEIC) under the International Health Regulations. This designation signaled an extraordinary event that required coordinated international action, including guidance on screening, surveillance, and response capacity. The declaration helped mobilize greater global support as cases continued to climb.

   • WHO IHR

7. UN Security Council calls Ebola a security threat

   Sep 18, 2014Labels: UN Security, Resolution 2177, international security

   In September 2014, the UN Security Council adopted Resolution 2177, identifying the Ebola outbreak as a threat to international peace and security. This was unusual for a disease event and reflected concern about state stability, economic disruption, and regional spillover. The resolution supported stronger international coordination and resources for the affected countries.

   • UN Library
   • IFRC

8. WHO declares Senegal and Nigeria Ebola-free

   Oct 20, 2014Labels: WHO declarations, Senegal, Nigeria

   By October 2014, WHO declared transmission ended in Senegal and Nigeria after the required period with no new cases. These outcomes showed that targeted measures—like rapid case isolation, contact tracing, and safe burials—could stop Ebola even in places with major travel links. At the same time, Guinea, Liberia, and Sierra Leone continued to face intense transmission.

   • PAHO WHO
   • Britannica

9. WHO declares Liberia free of Ebola (first time)

   May 9, 2015Labels: Liberia, WHO declaration, transmission interrupted

   In May 2015, WHO announced that Liberia had interrupted Ebola transmission after 42 days with no new laboratory-confirmed cases. The declaration marked a major turning point for the country that had experienced extreme pressure on hospitals and essential services during peak transmission. It also showed that sustained community measures and treatment capacity could reverse an expanding epidemic.

   • WHO

10. Liberia declared Ebola-free again after re-emergence

    Sep 3, 2015Labels: Liberia, re-emergence, heightened surveillance

    After Ebola re-emerged in Liberia in mid-2015, WHO declared transmission ended again in September 2015 following another 42-day period without cases. The reappearance highlighted that “zero cases” did not remove risk, especially with cross-border exposure and the possibility of lingering infection in survivors. Liberia entered heightened surveillance to detect new cases early.

    • WHO

11. WHO declares Sierra Leone stops Ebola transmission

    Nov 7, 2015Labels: Sierra Leone, WHO declaration, enhanced surveillance

    In November 2015, WHO declared that Sierra Leone had stopped Ebola virus transmission after 42 days since the last case tested negative twice. The country moved into a period of enhanced surveillance to detect any flare-ups quickly. This milestone narrowed the main epidemic focus to remaining transmission in Guinea and later flare-ups in Liberia.

    • WHO
    • CDC Archive

12. WHO declares end of Ebola transmission in Guinea

    Dec 29, 2015Labels: Guinea, WHO declaration, epidemic origin

    In December 2015, WHO declared the end of Ebola transmission in Guinea after 42 days with no new cases following the last patient’s second negative test. Because Guinea was where the epidemic began, this announcement was a symbolic and operational milestone. However, WHO and partners emphasized continued vigilance because small flare-ups had occurred before and could happen again.

    • WHO
    • BMJ

13. WHO terminates Ebola PHEIC for West Africa

    Mar 29, 2016Labels: WHO, PHEIC termination, IHR Emergency

    In March 2016, WHO ended the PHEIC status for the West Africa Ebola outbreak based on advice from its International Health Regulations Emergency Committee. Ending the emergency designation reflected improved control and stronger response capacity across the region. WHO still warned that flare-ups could occur and that surveillance and rapid response remained essential.

    • WHO IHR

14. WHO declares West Africa epidemic’s final Liberia flare-up over

    Jun 9, 2016Labels: Liberia, final flare-up, heightened surveillance

    In June 2016, WHO declared the end of Liberia’s most recent Ebola outbreak, 42 days after the last confirmed patient tested negative for the second time. This was the last known active chain from the 2014–2016 crisis, and it marked a clear endpoint to the region’s emergency phase. Liberia entered a 90-day period of heightened surveillance to ensure any new cases would be found and contained quickly.

    • WHO