Epidemics That Didn't Happen

Case Study:

in West Africa

How improved systems and skills following deadly epidemics contained two Ebola outbreaks  
Resolve To Save Lives
Microscopic image of the Ebola virus
Virus Image: Microscopic image of the Ebola virus. Courtesy: Frederick A. Murphy

About Ebola

Rare but deadly, Ebola Virus Disease is caused by a virus thought to have originated in bats. In recent years, humans have also become reservoirs of the virus,1 spreading it through bodily fluids.2 Although there have been relatively few Ebola outbreaks since the virus was discovered in 1976, they have been devastating, with death rates ranging from 20% to 90%.

Initial symptoms are often flu-like, but can progress to liver and kidney dysfunction and internal and external bleeding.3 Treatments, such as oral or intravenous fluids and monoclonal antibodies, can greatly improve chances of survival.4 Effective vaccines against the Zaire strain of the virus have been available since 2019, but supply remains limited.5 Nonetheless, the World Health Organization (WHO) has been able to coordinate swift vaccine delivery during recent outbreaks.

In 2014-2016 and 2018-2020, gaps in detection and response led to delays that allowed two Ebola outbreaks to become epidemics. The first, in West Africa, began in Guinea and spread to Liberia and Sierra Leone, as well as seven other countries including the United States and Italy, between 2014 and 2016. Subsequent analysis pointed to failures that hampered response efforts.6

In the past decade, two Ebola epidemics claimed nearly 14,000 lives.

In 2014, Guinea lacked a formal emergency response system, a public health agency and trained field epidemiologists.7  Communication about how to limit risk of Ebola spread was poorly handled, leading to resistance, mistrust and the viral spread of misinformation; one rumor held that the virus wasn’t even real.8 That entire parts of the country were simultaneously cordoned off to prevent the spread of disease only added to a culture of fear.9 Border controls to limit spread to neighboring countries were not established until five months after the outbreak had been declared.10 Vaccines were not available at the outset of the outbreak; as the epidemic progressed, only those enrolled in clinical trials could access them. Vaccination rollout was further hampered by misinformation, including that the vaccine made women infertile or men impotent.11

By the time the West Africa Ebola epidemic ended in 2016, approximately 28,600 people had been infected, and 11,325 people had died. The cost to the global economy was estimated to be $53 billion.12

Despite success containing several earlier Ebola outbreaks, the Democratic Republic of the Congo (DRC) was hampered from the start in its response in 2018, resulting in an epidemic that lasted until 2020. Due to ongoing regional conflict, the disease surveillance system had broken down. Health care workers were on strike because of a salary payment dispute in May of 2018—the time when investigations later determined the first case of Ebola had emerged.13 As a result, no suspected cases were identified, and no alerts were issued for two months. The outbreak became so large that, at its peak, 16,000 local responders were required, in addition to 1,500 staff sent by WHO and more deployed by other international partners.14 A total of 171 health care workers were infected,15 and in total the epidemic caused about 2,280 deaths among 3,470 diagnosed cases.

In 2021, Ebola outbreaks of the Zaire strain emerged again in both Guinea and DRC under strained circumstances, with each country dealing with multiple infectious disease outbreaks simultaneously—including COVID-19. But the outcomes were drastically different. Guinea’s outbreak was declared over after six months and 12 deaths. And the outbreak in DRC ended after three months and 11 deaths. Vaccines were administered successfully, health care worker infections were limited and neither outbreak spread beyond the region in which it emerged.

What changed?

Guinean Red Cross workers carrying the corpse of a victim of Ebola during the 2014-2016 epidemic
Guinean Red Cross workers carrying the corpse of a victim of Ebola during the 2014-2016 epidemic. Courtesy: KENZO TRIBOUILLARD/AFP via Getty Images


On January 18, 2021, a nurse from the N’zérékoré Region of Guinea arrived at a clinic in Gouécké with a headache, vomiting and fever, among other symptoms. She was diagnosed with typhoid and released. Days later, her condition had become so severe that she was admitted to a hospital, where she was diagnosed with malaria and salmonella. Following discharge, however, her condition only worsened. She sought care at a private clinic and subsequently from a traditional healer, to no avail. She died several days later.16

In the week following her February 1 funeral, the woman’s husband and other family members became ill.17 Some family members’ symptoms were recognized as consistent with viral hemorrhagic fever and reported to the national epidemic alert system on February 11. Blood specimens were taken from two hospitalized patients on February 12, and the nearby regional lab confirmed the infections to be Ebola the next day.18 Meanwhile, the woman’s husband had traveled across the country to the capital city of Conakry for treatment, creating potential new exposures. He too was confirmed to have Ebola, and on February 14, the government announced the outbreak.

Amid simultaneous outbreaks of yellow fever, measles, polio and COVID-19, the new Ebola outbreak—undetected for nearly a month—threatened to hit the same region of the country where the massive 2014-2016 Ebola epidemic emerged.


Within 24 hours of the first alert confirming Ebola’s reemergence, Guinea activated national and district emergency operations centers (EOCs) to coordinate containment.19 Since the 2014-2016 Ebola epidemic, Guinea had established the National Agency for Health Security (ANSS) to aid in detecting and stopping outbreaks, and with the support of the U.S. Centers for Disease Control and Prevention and other partners, had established a national EOC as well as 38 EOCs at the district level.20 Furthermore, the country had invested in hiring and training a range of public health officials—from epidemiologist disease detectives to risk communication and community engagement specialists, who could help build trust and combat misinformation—to quickly respond to the outbreak. ANSS provided a centralized coordination hub from which officials could activate an effective response. The day after the lab tests confirmed Ebola, ANSS deployed teams of staff and partners from key stakeholder organizations to begin thorough case investigation and contact tracing.21,22 The Africa Centres for Disease Control and Prevention (Africa CDC), which was established in 2017 by the African Union, partly in response to the 2014-2016 Ebola outbreak, began holding coordination meetings the day following the outbreak declaration and deployed a support team to Guinea two days later, on February 17.23 Teams of public health workers, all coordinated by ANSS, sprang into action to monitor the outbreak’s spread. More than 10,000 additional alerts of potential cases were triggered, 96% of which were investigated. More than 1,100 contacts were identified from 23 initial cases, and nearly all of them were monitored daily. Because the outbreak’s epicenter was located near the borders of Liberia and Côte d’Ivoire, officials held coordination meetings among the three countries and conducted over 2.5 million screenings at their points of entry.24 In local areas where Ebola was known to be present, officials established screening checkpoints.25
A health worker preparing a dose of Ebola vaccine
A health worker preparing a dose of Ebola vaccine. Courtesy: ISSOUF SANOGO/AFP via Getty Images