The Ebola virus spread in humans for 3 months before it was first identified in Guinea and evaded early detection in Liberia and Sierra Leone before exploding onto the scene in a worst-case-scenario that quickly outstripped response efforts, the World Health Organization (WHO) said today in a lengthy report on the epidemic's first 12 months.
An investigation by the WHO and Guinea's health ministry found that the index patient was probably an 18-month-old boy from the remote village of Meliandou in Guinea's Gueckedou district. Though in a forested region, many of the trees in the area where the boy lived had been destroyed due to foreign mining and timber operations, which might have brought potentially infected animals, including bats, in closer contact with people.
The boy—known to play near a hollow tree infested with bat—got sick with fever, black stools, and vomiting on Dec 26, 2013, and died 2 days later. By the second week of January, members of his immediate family got sick with similar symptoms and rapid death, and illnesses spread to community members and hospital staff.
Over the next few weeks, the outbreak smoldered, spreading to four other subdistricts, with a local report not reaching district health officials until Jan 24. Within the next few days, the first investigation, plus a second one that involved at team from Doctors without Borders (MSF), hinted at a possible cholera outbreak.
On Feb 1, a member of the boy's extended family brought the virus to Conakry, the country's capital, with illnesses spreading to four other districts and a host of other villages along the man's travel route.
Guinea's health ministry issued its first alert about an unidentified disease outbreak on Mar 13, which triggered emergency management operations at the WHO's African regional office for a possible Lassa fever event. An investigation by a team from the health ministry, WHO, and MSF fleshed out previously unknown links between the cases and pinpointed Gueckedou City as the outbreak's epicenter.
Tests at the Pasteur Institute identified the outbreak's cause as a filovirus on Mar 21, and lab tests the next day narrowed it to the Ebola Zaire species, one of the most deadly strains. The WHO's first outbreak report came on Mar 23, with 49 cases and 29 deaths reported at that time.
'A fire in a peat bog'
By the time the WHO's announcement came out, infections had already been exported to Liberia and Sierra Leone, where the virus wasn't detected until illnesses spilled into capital cities, where quickly multiplying chains of transmission overwhelmed responders.
With the Ebola outbreak being West Africa's first, health officials in the region were unfamiliar with the disease and saddled with weak health systems, leaving all three countries unprepared to manage the outbreak from the outset. Other unique factors that fueled the spread in West Africa are already well known: virus' transmission in urban settings, high levels of population movement across porous borders, and cultural practices that enhanced transmission and fostered denial of the disease and resistance to control efforts.
Health workers on the frontlines were among the hardest-hit groups. And as the outbreak progressed, the boundaries between high- and low-risk areas blurred, posing risks in treatment units as well as out in the community.
Infections in health staff were highest early in the outbreak, but they climbed again in the last part of the year, a phenomenon that experts are investigating. The WHO said reasons could include, for example, lapses in infection control measures in Liberia and exhaustion among staff in Sierra Leone.
The unprecedented spread of the virus across such a wide geographic region outpaced the international response at nearly every level, the WHO said, likening transmission to a "fire in a peat bog," flaring on the surface, but smoldering underground after responders stamp it out, popping up again in the same place or somewhere else.
"Unlike other humanitarian crises, like an earthquake or a flood, which are static, the Ebola virus was constantly—and often invisibly—on the move," the WHO said.
The response sparked an outpouring of help from nongovernmental agencies and other countries, pushing them into functions they were often unfamiliar with. For example, the WHO said one of its new roles was supervising and funding the construction of treatment centers.
Despite the response from many groups, the outbreak exceeded capacities for much of the year or wasn't there when the outbreak countries needed it most, with insufficient numbers of foreign health workers to staff treatment centers as the most acute shortage.
One virus, three outbreak patterns
West Africa's Ebola outbreak played out differently in each of the three countries, the WHO said.
Guinea's disease patterns have oscillated, with the country experiencing three cycles of intense transmission. Persistent barriers to curbing transmission have been strong community resistance in some areas, especially rural ones, and a highly mobile population.
In Liberia, a spurt of cases in early April, with some spread to Monrovia, was followed by what appeared to be a lull. New infections in the capital surged, however, with the first hospitalized patients sparking several chains of transmission, fueling an exponential spread of Ebola.
The outbreak prompted government actions, such as market closures, curfews, movement restrictions, quarantine of Monrovia slums, and a victim cremation order, which led to several problems in handing dead bodies and ran counter to cultural funeral practices. By Sep 8, Liberia had become the hardest-hit of the three countries, with treatment centers overflowing as soon as they were opened.
By the end of September, the rate of infections in the country started dropping, giving responders hope that control measures will have a similar effect in Guinea and Sierra Leone. However, health officials are still concerned about new disease activity in rural areas, which could again seed transmission chains in urban areas.
Sierra Leone's disease activity was marked by a silent and slow buildup of undetected cases, linked to the index case in Guinea. The country experienced a burst of cases in late May and early June, with numbers growing exponentially and seeing the most dramatic jump in November, according to the WHO.
The disease struck several of the country's health providers, including its leading expert on filoviruses.
Listening to community members is a lesson learned in Sierra Leone, the WHO noted. For example, in the face of scarce treatment beds and the need to isolate sick patients, local people asked for tools such as tents and cooking utensils to self-isolate near their homes, an approach that was tried in a small area and saw success.
Rampant and sustained Ebola activity in Freetown and other western parts of the country in early December made Sierra Leone the country with the most infections, prompting a response surge that lasted until the end of the year.
Key global response moments
The WHO included a timeline of its response actions, which began with its first disease notification on Mar 23. By Apr 8, a team of investigators from the WHO and its partners warned that the outbreak was one of the most challenging Ebola events the world has ever faced.
It highlighted pivotal moments, including a Jun 23 session at a high-level meeting in Conakry, attended by representatives from MSF and other groups, that led to a call for the WHO to take a stronger leadership role in responding to the outbreak, and the identification of an exported case in Nigeria, which alarmed the global community over the risk of international spread. That event led to the appointment of an emergency committee that on Aug 8 recommended that the WHO declare a public health emergency of international concern.
The agency has been widely criticized—including by MSF—for not declaring the emergency sooner and not taking enough concrete steps earlier.
In late August the WHO issued a response roadmap, and its top leaders briefed world leaders on the unprecedented scale of the outbreak, actions that led to the formation of the United Nations' first-ever health mission, the UN Mission for Emergency Ebola Response (UNMEER) in September.
Other sections of today's WHO report reprise its technical guidance, global efforts to speed the development of drugs and of vaccines to help battle the outbreak, and preparedness and response actions that helped limit the spread of the disease in Nigeria, as well as in Senegal and Mali, which also saw limited cases.
A world unprepared
In a section on warnings the world didn't heed with the Ebola outbreak, the WHO said a review of the global response to the 2009 H1N1 pandemic pointed out that the WHO systems were geared toward short-term emergencies and recommended strengthened preparedness steps, including a bigger global health reserve workforce, a contingency fund, and stepped-up research programs.
The WHO said the Ebola outbreak showed that the world didn't respond to the recommendations and that a review shows that only about a third of nations have essential capacities required by International Health Regulations.
"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," it said.
On Jan 25 the WHO executive board will consider a set of proposals that would change the way the WHO responds to emergencies, based on its experience with West Africa's Ebola outbreak.
In the last chapter of the report, the WHO reviewed lessons learned in the outbreak and spelled out the issues that need to be addressed in 2015. They include a new, more strategic response plan to get cases down to zero in the affected countries, enabling unaffected countries to prevent outbreaks, strengthening health systems, and beefing up research on diagnostics, treatments, and vaccines.
The group also highlighted other issues to tackle, such as making sure health workers in outbreak areas are properly compensated, stigma in survivors, and building and maintaining support for the ongoing response among other nations.
- The International Federation of Red Cross and Red Crescent Societies (IFRC) today is investigating a fatal Ebola infection in one of its staff nurses who was working in an IFRC treatment center in Kenema, Sierra Leone. The man died on Jan 13, and his infection was confirmed later that day. The group said it's not clear if the nurse was infected at home or at the treatment center and added that it is monitoring 29 of the man's close contacts. The death is the first from Ebola in an IFRC volunteer or staff member in Sierra Leone. Moulaye Camara, who heads the IFRC delegation in Sierra Leone, said in a statement that although the group has seen encouraging signs in the country, "Ebola is still very real and it is still here. It is critical we remain vigilant . . . until we are down to zero cases."
- A 3-day meeting began yesterday at WHO headquarters in Geneva involving leaders from high-risk African nations to help them boost their preparedness against Ebola. In a statement yesterday, the WHO said attendees will review the outcome of missions to the countries, review a revised preparedness checklist and a dashboard to help nations monitor their progress in implementing their national plans, and decide on a multipartner action plan.
- In a brief update today the WHO said the number of Ebola infections in the three hardest-hit countries has grown to 21,329 cases, which include 8,444 deaths. The totals, which include cases reported as of Jan 12, reflect a gain of 68 illnesses and 30 deaths since the WHO's update yesterday.
Jan 15 WHO press release
Jan 15 WHO report on 12 months of Ebola in West Africa
Jan 15 IFRC press release
Jan 14 WHO statement on meeting
Jan 15 WHO situation report