One year after the first Ebola cases started to surface in Guinea, WHO is publishing this series of 14 papers that take an in-depth look at West Africa’s first epidemic of Ebola virus disease.
This assessment looks at how West Africa’s epidemic of Ebola virus disease has evolved over the past year, giving special attention to the situation in Guinea, Liberia, and Sierra Leone. The success stories in Senegal, Nigeria, and likely Mali are also described to show what has worked best to limit onward transmission of Ebola following an imported case and bring the outbreak to a rapid end. The fact that a densely populated city like Lagos was successful in containing Ebola offers encouragement that other developing countries can do the same.
An overview of how the outbreak in the Democratic Republic of Congo evolved and was brought under control underscores the many differences between the outbreaks in West Africa and in equatorial Africa, where all previous outbreaks since the first two in 1976 have occurred.
Key events in the WHO response are outlined to show how initial control efforts were eventually overwhelmed by the wide geographical dispersion of transmission, the unprecedented operational complexity of the outbreaks, and the many factors that undermined the power of traditional containment measures to disrupt transmission chains. These factors are also described.
In efforts coordinated by WHO, scientists and the pharmaceutical industry have geared up to develop, test, license, and introduce the first Ebola vaccines, therapies, and point-of-care diagnostic tests. As a strong expression of solidarity with the people of West Africa, these groups are attempting to compress work that normally takes two to four years into a matter of months.
Finally, the assessment takes a look at the potential future evolution of the Ebola epidemic. Based on what has been learned during this first year, what critical strategies and interventions will give countries and their partners the best chance of bringing the outbreaks under control?
Conclusion — Ebola response: What needs to happen in 2015
As 2014 progressed, the world learned a great deal from the largest and longest Ebola outbreak in history, and these lessons have shaped a more strategic approach going forward.
Much was learned during 2014. The epidemic in West Africa — the largest and longest in the nearly four-decade history of this disease — yielded greater clinical understanding of the pathology of Ebola virus disease and ways to improve survival rates jumped ahead. We have gained much greater understanding at the operational level: what specific packages of control interventions will have the greatest impact on getting transmission down?
Scientific research about the disease escalated dramatically, as has research and development to develop new medical products for prevention, treatment and possibly cure.
The four biggest lessons from 2014
The biggest and most obvious lessons are four-fold.
First, countries with weak health systems and few basic public health infrastructures in place cannot withstand sudden shocks, whether these come from a changing climate or a runaway virus. Under the weight of Ebola, health systems in Guinea, Liberia and Sierra Leone collapsed. People stopped receiving — or stopped seeking — health care for other disease, like malaria, that cause more deaths yearly than Ebola.
In turn, the severity of the disease, compounded by fear within and beyond the affected countries, caused schools, markets, businesses, airline and shipping routes, and borders to close. Tourism shut down, further deepening the blow to struggling economies. What began as a health crisis snowballed into a humanitarian, social, economic and security crisis. In a world of radically increased interdependence, the consequences were felt globally.
The evolution of the crisis underscored a point often made by WHO: fair and inclusive health systems are a bedrock of social stability, resilience and economic health. Failure to invest in these fundamental infrastructures leaves countries with no backbone to stand up under the weight of the shocks that this century is delivering with unprecedented frequency.
Second, preparedness, including a high level of vigilance for imported cases and a readiness to treat the first confirmed case as a national emergency, made a night-and-day difference. Countries like Nigeria, Senegal and Mali that had good surveillance and laboratory support in place and took swift action were able to defeat the virus before it gained a foothold.
Third, no single control intervention is, all by itself, sufficiently powerful to bring an Ebola epidemic of this size and complexity under control. All control measures must work together seamlessly and in unison. If one measure is weak, others will suffer.
Aggressive contact tracing will not stop transmission if contacts are left in the community for several days while test results are awaited. Good treatment may encourage more patients to seek medical care, but will not stop community-wide transmission in the absence of rapid case detection and safe burials. In turn, the powers of rapid case detection and rapid diagnostic confirmation are diminished in the absence of facilities for prompt isolation. As long as transmission occurs in the community, medical staff following strict protocols for infection prevention and control in clinics will be only partially protected.
Finally, community engagement is the one factor that underlies the success of all other control measures. It is the linchpin for successful control. Contact tracing, early reporting of symptoms, adherence to recommended protective measures, and safe burials are critically dependent on a cooperative community. Having sufficient facilities and staff in place is not enough. In several areas, communities continued to hide patients in homes and bury bodies secretly even when sufficient treatment beds and burial teams were available. Experience also showed that quarantines will be violated or dissolve into violence if affected communities are given no incentives to comply.
An epidemic with two causes
The persistence of infections throughout 2014 had two causes. The first was a lethal, tenacious and unforgiving virus. The second was the fear and misunderstanding that fuelled high-risk behaviours. As long as these high-risk beliefs and behaviours continue, the virus will have an endless source of opportunities to exploit, blunting the power of control measures and deepening its grip. Like the populations in the three countries, the virus will remain constantly on the move.
Getting to zero means fencing the virus into a shrinking number of places where all transmission chains are known and aggressively attacked until they break. It also means working within the existing context of cultural beliefs and practices and not against them. As culture always wins, it needs to be embraced, not aggravated, as WHO aimed to do with its protocol on safe and dignified burials.
A more strategic emergency response
As the new year began, a revised response that builds on accumulated experiences was mapped out by WHO. This new response plan adopts what has been shown to work but also sets out new strategies designed to seize all opportunities for getting the number of cases down to zero.
Community resistance must be tackled by all outbreak responders with the greatest urgency. Concrete guidance on ways of doing this is likely to emerge from an analysis of Sierra Leone’s Western Area Surge, which included several strategies for engaging communities and responding to their concerns. As was learned during 2014, community leaders, including religious leaders as well as tribal chiefs, can play an especially persuasive role in reducing high-risk behaviours.
Apart from low levels of community understanding and cooperation, contact tracing is considered the weakest of all control measures. Its poor performance likewise needs to be addressed with the greatest urgency. For example, in Guinea, which has the most reliable data, only around 30% of newly identified cases appear on contact lists. In all three countries, the number of registered contacts for confirmed cases is too low. In Sierra Leone, some lists of contacts include family members only, and no one from the wider community.
As the year evolved, outbreak responders learned the importance of tailoring response strategies to match distinct needs at district and sub-district levels. An understanding of transmission dynamics at the local level usually reveals which control measures are working effectively and which ones need improvement. Doing so requires better district-level data and, above all, better coordination. The outbreaks will not be contained by a host of vertical programmes operating independently. Again, all control measures must work seamlessly and in unison.
At year end, as cases flared up in new areas or moved from urban to rural settings, a clear need emerged for rapid response teams and for agile and flexible strategies that can change direction — and location — quickly. In WHO’s assessment, all three countries now have sufficient numbers of treatment beds and burial teams, but these are not always located where they are most needed. As was also learned during 2014, transporting patients over long distances for treatment does not work, either for families and communities or in terms of its impact on transmission.
As long as logistical problems persist, community confidence in the response will remain low. People cannot be expected to do as they are told if the effort leaves them visibly worse off — quarantined without food, sleeping in the same room with a corpse for days — instead of better off. These problems are compounded by poor road systems and weak telecommunications in all three countries. In Liberia, for example, health officials in rural areas are lucky if they have an hour or two of internet connectivity per week. This weakness defeats rapid communication of suspected cases, test results and calls for help, thus ensuring that response efforts continue to run behind a virus that seizes every opportunity to infect more people.
A decentralized strategy — and an ethical imperative
As the response decentralizes to the sub-national level, fully functional emergency operations centers, with local government health teams integrated and playing a leadership role, must be established in each county, district and prefecture in the three countries. These centres will drive the step-change in field epidemiology capacity needed to achieve high-quality surveillance, rapid and complete case-finding, and comprehensive contact tracing — the fundamental requirements for getting to zero.
A decentralized response also demands urgent attention to well-known gaps and failures in collecting, collating, managing and rapidly sharing information on cases, laboratory results and contacts. Understanding and tackling the drivers of transmission in each area call for enhanced case investigation and analytical epidemiology. Tools for collecting and sharing this information need to be standardized and put into routine use by governments and their partners.
Another major problem is the unacceptably large difference in case fatality rates between people who receive care in affected countries (71%) and foreign medical staff (26%) who were evacuated for specialized treatment in well-resourced countries. Getting case fatality down in affected countries is an ethical imperative.
Innovation needs to be encouraged, publicized, tested and funnelled into control strategies whenever appropriate. Mali used medical students with training in epidemiology to rapidly increase the number of contact tracers. Guinea drew on its corps of young and talented doctors to strengthen its outbreak response, with training provided by WHO epidemiologists. These staff know the country and its culture best. They will still be there long after foreign medical teams leave.
In Sierra Leone, the government-run Hastings Ebola Treatment Center, a 123-bed facility entirely operated by local staff, has defied statistics elsewhere in the country with its survival rates. Six out of every 10 patients treated there make a full recovery. As noted by an infection control specialist working on the wards, the only patients that cannot be saved are those who wait too long to seek care. After noting that Ebola virus disease has some similarities with cholera, staff at the facility made intravenous administration of replacement fluids a mainstay of the routine treatment protocol.
The pattern of transmission seen throughout 2014 makes a final conclusion obvious: cross-border coordination is essential. Given West Africa’s exceptionally mobile populations, no country can get cases down to zero as long as transmission is ongoing in its neighbors.
Prevent outbreaks in unaffected countries
With the increasing number of cases and infected prefectures in Guinea, the risk of new importations to neighboring countries is also growing. In terms of preparedness, the most urgent need is for active surveillance in the areas bordering Mali, Senegal, Guinea-Bissau and Cote d’Ivoire, through the deployment of additional human and material resources, and the introduction of standard performance monitoring and reporting on a weekly basis.
Improvements in contact tracing and monitoring in the second phase of the response provide an opportunity to substantially enhance the efficacy of exit screening. Doing so further reduces the risk of new Ebola exportations from affected areas. As contact tracing improves, lists of active contacts could be systematically shared with border and airport authorities to link this information with exit screening.
Get health systems functioning again — on a more resilient footing
Much debate has focused on the importance of strengthening health systems, which were weak before the outbreaks started and then collapsed under their weight. In large parts of all three countries, health services have disintegrated to the point that essential care is either unavailable or not sought because of fear of Ebola contagion.
As some have argued, cases will decrease fastest when a well-functioning health system is in place. That argument also points to the need to restore public confidence — which was never high — in the public health system. Targeted drug-delivery campaigns that aimed to treat and prevent malaria were well-received by the public and are a step in the right direction, but much more needs to be done.
Although virtually no good systems for civil registration and vital statistics are still functioning in the three countries, indirect evidence suggests that childhood deaths from malaria have eclipsed Ebola deaths. Liberia, for example, had around 3500 malaria cases each month prior to the outbreak, with around half of these cases, mainly young children, dying. An immediate strengthening of health systems could reduce these and many other deaths, while also restoring confidence that health facilities can protect health and heal disease.
Others argue that efforts must stay sharply focused on outbreak containment. As this argument goes, response capacity is limited and must not be distracted. This argument favours a step-wise approach that initially concentrates on strengthening those health system capacities, like surveillance and laboratory services, that can have a direct impact on outbreak containment.
For its part, WHO sees a need to change past thinking about the way health systems are structured. As the Ebola epidemic has shown, capacities to detect emerging and epidemic-prone diseases early and mount an adequate response need to be an integral part of a well-functioning health system. Outbreak-related capacities should not be regarded as a luxury or added as an afterthought. Otherwise, the security of all health services is placed in jeopardy.
Step up research
Research aimed at introducing new medical products needs to continue at its current accelerated pace. Executives in the R&D-based pharmaceutical industry have expressed their view that all candidate vaccines must be pursued “until they fail”. They have further agreed that the world must never again be taken by surprise, left to confront a lethal disease with no modern control tools in hand.
New tools will likely be needed to get to zero. For example, vaccines to protect health care workers may make it easier to increase the numbers of foreign and national medical staff. Better therapies — and improved prospects of survival — may encourage more patients to promptly seek medical care, greatly increasing their prospects of survival.
As cases decline, robust and reliable point-of-care diagnostic tests will boost efforts to break transmission chains. Rapid diagnostic tests can support efficient patient triage and reduce the time that contacts or suspected cases are held in facilities alongside confirmed cases, where they are at risk of infection. Such tests could also facilitate the screening of patients at regular health care facilities, thus reducing the risk of transmission from undiagnosed cases to unprotected medical staff.
However, all new control tools must be introduced carefully and in ways that guard against both unrealistic public expectations and unfounded fears. For example, vaccines may not confer full protection; the duration of protection could be brief; a booster shot may be needed. Not all experimental therapies can be easily and safely administered in resource-constrained settings.
Such tools may also be needed for the future. Researchers have identified at least 22 African countries that have the ecological conditions and social behaviors that put them at risk of future outbreaks of Ebola virus disease.
Mine every success story
Operational research is needed to understand why some areas have stopped or dramatically reduced transmission while others, including some in the same vicinity and with similar population profiles, remain hotspots of intense transmission.
Did the striking and robust declines in Lofa County, Liberia, and Kailahun and Kenema districts in Sierra Leone occur because devastated populations learned first-hand which behaviours carried a high risk and changed them? Or can the declines be attributed to simultaneous and seamless implementation of the full package of control measures, as happened in Lofa country? Answers to these questions will help refine control strategies.
Research is also needed to determine how areas that have achieved zero transmission can be protected from re-reinfection. Some success stories look real and robust, but these are only pockets of low or zero transmission in a broad cloak of contamination.
At every opportunity, strategies devised for the emergency response should be made to work to build basic health capacities as well. Some success stories can serve as models.
Liberia demonstrated how quickly the quality of data and reporting can improve, thus strongly supporting the strategic targeting of control measures at district and sub-district levels.
Sierra Leone showed how laboratory services can be strengthened and expanded, reducing waiting times for test results close to what is seen in countries with advanced health systems while also supporting the better clinical management of cases.
Each and every survivor is also a success story. In an effort to fight the stigma that so often haunts these people, many treatment centres hold celebratory ceremonies when survivors are released from treatment. Each is given a certificate as proof that they pose no risk to families or communities.
Get the incentives — and support — right
Both foreign and domestic medical staff have worked in the shadows of death, placing their lives at risk to save the lives of others. In many places, these staff also risked losing their standing in communities, given the fear and stigma attached to anything or anyone associated with Ebola.
These people deserve to be honoured and respected. They also deserve to be paid on time and given safe places to work. Timely and appropriate payment to national staff remains problematic. More studies are currently under way to identify the circumstances under which health care workers continue to get infected.
Special efforts are also needed to improve safety at private health facilities, in pharmacies, and among traditional healers, as evidence suggests the risk of transmission is highest in these settings. The number of hospitals that remain closed or virtually empty supports the conclusion that doctors and nurses are most likely getting infected while treating patients in community settings.
Incentives also need to be in place to ensure that foreign medical teams stay in countries long enough to understand conditions, including political and social as well as operational issues, and pass on this knowledge to replacement staff. Towards the end of the year, WHO ensured that its field coordinators stayed in countries for several months.
The “post-Ebola syndrome”
Given the fear and stigma associated with Ebola, people who survive the disease, especially women and orphaned children, need psychosocial support and counseling services as well as material support. They may need medical support as well. A number of symptoms have been documented in what is increasingly recognized as a “post-Ebola syndrome”.
Efforts are now under way to understand why these symptoms persist, how they can best be managed, whether they are caused by the disease, and whether they might be linked to treatment or the heavy use of disinfectants. WHO staff have developed an assessment tool that is being used to investigate these issues further.
Maintain unwavering commitment at national and international levels
Media coverage of the Ebola crisis peaked in August, when two American missionaries and a British nurse became infected in West Africa and were medically evacuated for treatment in their home countries. Coverage increased dramatically in October, when the USA and Spain confirmed their first locally transmitted cases.
Ominous forecasts from various agencies — including 1.4 million cases by mid-January 2015 — contributed to the deepening of concern. The most accurate forecast, of 20 000 cases, was made in the WHO Ebola response roadmap, issued in late August. WHO later also made dramatic forecasts based on the assumption that control measures were not being scaled up fast enough.
Although the situation in Liberia at year end, especially in Monrovia, looked promising, optimism must remain cautious. As experiences in Guinea made clear, this is a virus that can go into hiding for some weeks, only to return again with a vengeance. In Liberia, as caseloads declined, evidence of complacency and “Ebola fatigue” rapidly appeared in some populations even though transmission continued.
The three countries will continue to need international support for some time to come, whether in the form of direct support for response measures or assistance in rebuilding their health services. Countries and the international community must brace themselves for the long-haul.
One overarching question hangs in the air. The virus has demonstrated its tenacity time and time again. Will national and international control efforts show an equally tenacious staying power?
A formal assessment of the response to the 2009 H1N1 influenza pandemic concluded that the world was lucky on that occasion, as the virus was so mild, but ill-prepared to cope with any severe and sustained emergencies in the future, as borne out by the Ebola epidemic.
In 2010, a review committee was convened under the provisions of the Internal Health Regulations to evaluate the response to the 2009 H1N1 influenza pandemic and assess the level of global preparedness for similar events in the future. As the committee concluded, “The world is ill-prepared to respond to a severe influenza pandemic or to any similarly global and threatening public-health emergency.”
Beyond implementation of core public-health capacities called for in the IHR, the committee expressed the view that global preparedness can be advanced through research, reliance on a multisectoral approach, strengthened health-care delivery systems, economic development in low and middle-income countries, and improved health status.
The committee noted that the WHO response to public health emergencies was framed by the Organization’s “dual role as a moral voice for health in the world and as a servant of its Member States.” It observed the limitation of WHO systems that were designed to respond to a geographically focal, short-term emergency, rather than a global, sustained, long-term event. The Ebola epidemic has been just such an event.
Needs: an army of reinforcements, a war chest, and modern weapons
The committee’s recommendations for strengthened preparedness included calls for the establishment of a more extensive global public health reserve workforce that could be mobilized as part of a sustained emergency response, the creation of a contingency fund for public health emergencies to support surge capacity, and pursuit of a comprehensive research and evaluation programme. The committee noted that these needs could not be met by WHO acting alone and required collaboration with the international community.
“As soon as the outbreak was confirmed on March 21, we started to work with the Ministry of Health and other partners to implement necessary measures. It is the first time the country is facing an Ebola outbreak, so WHO expertise in the area is valuable.”
Dr Zitsamele-Coddy, WHO Representative, Guinea
As the Ebola outbreak has revealed, the world did not respond to these recommendations, with none of these measures fully in place to support a response that could last for many more months to come. Furthermore, in November 2014, an IHR review committee found that only 64 of WHO’s 194 Member States had the essential surveillance, laboratory, data management, and other capacities in place to fulfil their obligations under the IHR.
As a result, WHO went into battle against this virus with no army of reinforcements to support a sustained response, no war chest to fund a surge, and weapons that date back to the Middle Ages.
Thanks to the generosity of the international community, the dedication of scientists, and the ingenuity of the pharmaceutical industry, solutions to two of these problems have a good chance of being found. Reinforcements are badly needed. Finding more experienced field epidemiologists and foreign medical teams to manage the newly built and planned treatment centres, and getting those centres and staff closer to where they are needed most, remain major challenges.
What needs to change
On 25 January 2015, the WHO Executive Board will hold a special session to discuss the Ebola epidemic and what needs to be done to bring it under control. To guide these discussions, WHO staff prepared six background papers, including proposals for changing the systems and structures used by WHO when it responds to emergencies.
In connection with a reform process currently under way at WHO, Executive Board members will consider the extent to which WHO is expected to be operational in the field during extended emergencies, with its staff directly coordinating or supervising the response, or whether the WHO role should be confined to technical guidance and advice. Both functions — providing technical assistance and direct aid are constitutionally mandated. The Board will also consider administrative and managerial arrangements between WHO headquarters and its six regional offices.
Chapter 11 — The importance of preparedness — everywhere
Although all cities with an international airport are theoretically at risk of an imported case, the need for preparedness is greatest in countries that share borders or have extensive travel and trade relations with the three hardest-hit countries.
The successful experiences in Senegal, Nigeria, and Mali demonstrated the importance of preparedness and having the capacities in place to mount a rapid and comprehensive emergency response. Given the devastation caused by Ebola virus disease in Guinea, Liberia, and Sierra Leone, countries worldwide are on high alert for imported cases and many have elaborate preparedness plans in place.
In addition, experiences in the US and Spain showed that conventional control measures, including isolation and exhaustive tracing and monitoring of contacts, can halt further spread quickly following locally-acquired infections.
Intelligence from rumour-tracking teams: worldwide vigilance is high
Throughout the year, small teams at WHO headquarters systematically gathered intelligence, using a dedicated internet search engine, about possible Ebola cases in non-affected countries. Staff in WHO country offices and partners, including nongovernmental agencies, working in the field provided another source of alerts to possible cases.
The system has a translation facility that lets it pick up rumours and hints suggesting an Ebola case in any language. Staff in WHO country offices and partners, including nongovernmental agencies, working in the field provided another source of alerts to possible cases.
From mid-October to year end, the system picked up more than 183,000 alert signals. These were rapidly screened by epidemiologists, who selected a subset for further examination, risk assessment, or investigation and verification. More than 150 signals required further investigation, with the peak seen in August.
Based on the number of rumours tracked, worldwide vigilance for imported cases was judged high.
While any country with an international airport was theoretically at risk of an imported case, the need for preparedness was considered greatest in countries with weak public health infrastructures and little or no diagnostic capacity to detect cases early. When investigating possible cases, WHO paid especially close attention to rumours in countries that share borders or have extensive travel and trade relations with the three hardest-hit countries.
A checklist helps assess preparedness and gaps
In early October, WHO convened a consultation in Brazzaville, Republic of Congo, to assess preparedness needs and identify ways to quickly improve operational readiness to respond to imported cases. The consultation had two main outcomes. The first was a compact preparedness checklist that set out core principles, standards, capacities, and practices that can be used by countries to assess their level of preparedness.
In its second outcome, the consultation identified 14 priority countries in Africa considered to be especially vulnerable and in greatest need of international support to improve preparedness: Benin, Burkina Faso, Cameroon, Central African Republic, Cote d’Ivoire, Ethiopia, Gambia, Ghana, Guinea Bissau, Mali, Mauritania, Niger, Senegal, and Togo.
In Senegal and Mali, preparedness measures were already being put in place when those two countries confirmed their first Ebola cases on 29 August and 23 October.
By the second week of December, assessment missions to all 14 priority countries had been completed. Assessments focused on the capacity of each country to detect, investigate, and report possible Ebola cases. An assessment was also made of each country’s capacity to mount a response that could hold onward transmission to a small number of cases.
The resulting national preparedness action plans gave international development partners guidance on specific areas where support was likely to have the greatest impact on preparedness. At the end of each preparedness mission, at least one technical expert remained on site to oversee the continuity and coordination of preparedness measures.
Work on preparedness has taken place in all WHO regions. Training courses, workshops, and simulation exercises have been undertaken for groups of countries, while visits have been made to more than 70 countries in all regions to review capacities first-hand, develop action plans, and provide direct support.
All regions have also developed their own Ebola task forces and have regional response plans in place. Emergency operation centres and rapid response teams are likewise in place.
Most experts warn countries to expect additional imported cases as 2015 progresses. Given the high level of worldwide vigilance, chances are good, especially in countries with well-developed health systems, that these cases will be detected early — before they have a chance to spark multiple new chains of transmission.
Chapter 10 — Successful Ebola responses in Nigeria, Senegal and Mali
At-risk countries had a distinct advantage by the summer of 2014: they had witnessed the devastation caused by Ebola and were on high alert to respond to an imported case as a national emergency.
Though no clinicians, laboratories, populations, or governments in West Africa had any experience with Ebola virus disease when the outbreaks started, at-risk countries had a distinct advantage by the summer of 2014. They had witnessed the tenacity of the virus, and the social and economic devastation it caused, and were on high alert to respond to an imported case as a national emergency. This high-level of alert characterized the responses in Nigeria, Senegal, and Mali and contributed to their success.
In an unprecedented event, the virus entered Lagos, Nigeria on 20 July in a symptomatic air traveller whose sister had just died from Ebola in Liberia. He vomited during the flight, on arrival and, yet again, in the car that drove him to a private hospital, where he told staff he had malaria. The protocol officer who escorted him later died of Ebola. As malaria is not transmitted from person to person, no staff at the hospital took protective precautions. Over the coming days, 9 doctors and nurses became infected and 4 of them died. No one who shared a flight with the index case developed the disease.
“The Ebola outbreaks and response in Nigeria and Senegal showed the world that the disease can be stopped if a country is adequately prepared from the outset. WHO is now working with all countries at-risk to help them meet the same standards for preparedness.”
Isabelle Nuttall, Director, Global Capacities, Alert and Response, WHO
When confirmation of Ebola virus as the causative agent was announced on 23 July, the news rocked public health communities all around the world. No one believed that effective contact tracing could be undertaken in a chaotic and densely populated city like Lagos, with many poor people living in crowded slums and a population that swelled and ebbed every day as people came to the city looking for work or returned home when unsuccessful. Many envisioned an urban apocalypse, with Nigeria seeding outbreaks in several other countries, as had happened in the past with the poliovirus.
The second shock came when a close contact of the index case entered the country’s oil hub, Port Harcourt, on 1 August. A doctor who treated him developed symptoms on 10 August and died of Ebola on 23 August. An investigation undertaken by Nigerian and WHO epidemiologists revealed an alarming number of high-risk and very high-risk exposures for hundreds of people.
In both cities, all the ingredients for an explosion of new cases were in place. That explosion never happened, thanks to the country’s strong leadership and effective coordination of an immediate and aggressive response. As in Senegal, an emergency operations centre was established, supported by the WHO country office. Also like Senegal, Nigeria had a first-rate virology laboratory, affiliated with the Lagos University Teaching Hospital, that was staffed and equipped to promptly diagnose a case of Ebola virus disease.
The government generously allocated funds and dispersed them quickly. Isolation facilities were built in both cities, as were designated Ebola treatment facilities. House-to-house information campaigns and messages on local radio stations, in local dialects, were used to ease public fears. Infrastructures and cutting-edge technologies in place for polio eradication, were repurposed to support the Ebola response, putting GPS systems to work for real-time contact tracing and daily mapping of transmission chains. Contact tracing reached 100% in Lagos and 99.8% in Port Harcourt.
In what WHO described as a “spectacular success story”, the country held the number of cases to 19, with 7 deaths. World-class epidemiological detective work eventually linked all cases back to either direct or indirect contact with the air traveller from Liberia. WHO declared Liberia free of Ebola virus transmission on 20 October.
The first case in Senegal was confirmed on 29 August in a young man who travelled to Dakar, by road, from his home in Guinea, where he had been in direct contact with an Ebola patient. Both the government and WHO treated that news as an emergency and responded accordingly. WHO despatched three senior epidemiologists with extensive frontline experience in containing some of history’s largest Ebola outbreaks. These epidemiologists worked shoulder-to-shoulder with staff from the Ministry of Health, MSF, and CDC to undertake urgent and thorough contact tracing.
Dakar was in a fortunately position as it is home to a world-class Senegalese foundation, the Pasteur Institute and its laboratory, which is fully approved by WHO to test quickly and reliably for viral haemorrhagic fevers, including Ebola. In an important innovation, Senegal set up a separate centre devoted to emergency Ebola measures, thus freeing the health system to continue to deliver routine services. That measure, backed by massive public information campaigns, helped relieved public anxieties and encourage cooperation with control measures.
All contacts were monitored daily and those with symptoms were immediately tested. All test results were negative. No onward transmission occurred. The single case fully recovered. WHO declared Senegal free of virus transmission on 17 October, 42 days after the second test on that single patient came back negative.
When Mali confirmed its first case on 23 October, in a two-year-old child from Guinea who later died, the country had been on high alert for months. Mali experienced a dress-rehearsal for imported Ebola cases in early April, when six suspected cases were detected and placed under observation. An isolation facility in Bamako, designed for the management of Lassa fever patients, was repurposed to safely receive the suspected cases for close monitoring. Patient samples were tested at the CDC in Atlanta and the Pasteur Institute in Dakar. All test results were negative.
As in Senegal and Nigeria, the country moved quickly in what the government and WHO regarded as an emergency situation. The child, who was symptomatic upon her arrival, and her family members had travelled extensively throughout the country using public transportation, also spending some hours with relatives in Bamako. Staff from WHO and other partners, already in the country to strengthen preparedness, shifted their work to support outbreak containment. Aggressive contact tracing was undertaken, with several close contacts monitored in a hospital setting. As in Senegal and Nigeria, the country could use is own high-quality laboratory facilities, in Bamako, that had been built, with support from the US National Institutes of Health, to safely handle hazardous samples from tuberculosis and HIV patients.
Days then weeks passed with no contacts showing symptoms. The country looked like it would pass through the event with a single case. Then, on 25 October, a Grand Imam from Siguiri prefecture in Guinea was admitted to Bamako’s Pasteur Clinic with a diagnosis of acute kidney failure. He died on 27 October. That single hospital admission ignited a chain of transmission that eventually led to seven additional cases and five deaths, including a doctor and a nurse who had treated the Imam.
The country was well-rehearsed in the emergency measures that needed to be taken swiftly. Hundreds of contacts were identified and placed under daily surveillance. Isolation facilities and an Ebola-designated treatment centre were constructed. In response to public fears and misperceptions, an innovative telephone hotline was established and began receiving around 6,000 calls per day. All calls were meticulously recorded and analysed each day, with information on the caller’s precise area of work or residence, occupation, and main concerns. Calls were then mined to uncover where public messages about the disease needed to be adjusted. Some callers reported suspected cases. All such reports were investigated. No further cases were identified.
Altogether, 433 contacts were identified and followed up for the 21-day incubation period. The last patient hospitalized in the Ebola treatment centre fully recovered and was released, following two negative tests, on 6 December. The last 13 contacts ended their monitoring period at midnight on 15 December. Vigilance remains high. If no further cases are detected, WHO will declare Mali free from active Ebola transmission on 18 January 2015.
Shared features of a successful response
The three countries shared a high level of vigilance that led to the rapid detection of an imported case and the rapid introduction of classical control measures. They also benefitted from government support at the highest level that treated the first case as a national emergency. Support from WHO epidemiologists at the start of the investigation was warmly welcomed.
All three countries had their own high-quality laboratories, facilitating the rapid detection or discarding of cases. Contact tracing was rigorous and most identified contacts were monitored in isolation. Local staff and existing infrastructures were used in innovative ways. For example, Mali used medical students with training in epidemiology to increase staff numbers for contact tracing. All three countries established emergency operations centres and recognized the critical importance of public information campaigns that encouraged community cooperation.