From crisis to sustainable development: lessons from the Ebola outbreak

Dr Margaret Chan
Director-General of the World Health Organization

London School of Hygiene and Tropical Medicine. Women in Science Lecture Series
10 March 2015

My good friends at the London School of Tropical Medicine and Hygiene, colleagues in public health, ladies and gentlemen,

The outbreak of Ebola virus disease that ravaged parts of West Africa in 2014 is the largest, longest, most severe, and most complex in the nearly four-decade history of this disease.

To date, nearly 24,000 cases and nearly 10,000 deaths have been reported in Guinea, Liberia, and Sierra Leone. This sum is an order of magnitude higher than the 2,400 cases reported in all 24 previous Ebola outbreaks combined.

A look at the factors that made last year’s outbreak so difficult and so devastating is important. That experience yields a number of lessons that need to be acted on with the utmost urgency.

Constant mutation and adaptation are the survival mechanisms of the microbial world. Changes in the way humanity inhabits the planet have given viruses and bacteria multiple new opportunities to exploit. New diseases are now emerging at an unprecedented rate. No one expects this trend to end.

Moreover, in a world of radically increased interdependence, international travel, and trade, there is no such thing as a local outbreak anymore.

Recent large outbreaks, just since the start of this century, have shattered a number of assumptions about the world’s vulnerability to new and re-emerging diseases, like Ebola.

As the century began, most experts believed that the exotic pathogens that cause so much misery in the developing world would never threaten wealthy countries, with their high standards of living and well-developed health systems.

Then came the SARS outbreak of 2003, a disease that took its heaviest toll on wealthy urban areas. SARS spread most efficiently in sophisticated hospital settings.

Scientists also assumed that threats could be predicted. When the virus that caused the 2009 influenza pandemic emerged in the Americas, attention was almost exclusively focused on the H5N1 avian influenza virus circulating in Asia as the most likely cause of the next pandemic.

Scientists assumed that the most likely breeding ground for new diseases was in the forests of Africa and the teeming cities of Asia. Then came the Middle East Respiratory Syndrome, or MERS, which emerged in the Kingdom of Saudi Arabia in 2012. No one expected that an arid desert environment, and camels instead of chickens, would give rise to a new disease.

Like these other outbreaks, Ebola in West Africa delivered a number of surprises. Understanding these surprises brings lessons that can help the world prepare for similar events in the future. They are certain to come.

Ladies and gentlemen,

The first surprise was the appearance of Ebola in a new geographical area.

Ebola, which first emerged in 1976, has shown an historical pattern of surfacing at irregular intervals, usually in remote rural areas, then going into hiding in some unknown reservoir in the forests, but always in the same parts of equatorial Africa.

Nothing from past experience prepared the world for last year’s arrival of the virus in West Africa.

To understand that event, we need to look at the state of health care in the three countries, the assumptions that drove the early response, and the cultural traditions that fed rapid spread.

Prior to 2014, Ebola was considered a rare disease. The only control tools available date back to the Middle Ages: early detection, isolation, infection control, and quarantine.

The largest previous outbreak, which occurred in Uganda in 2000, infected 425 people. With cases currently in the tens of thousands, the failure to develop vaccines and treatments has far more glaring consequences.

Guinea, Liberia, and Sierra Leone are among the poorest countries in the world. At the start of the outbreak, all three had only recently emerged from years of civil war and unrest that left basic health infrastructures damaged or destroyed and created a cohort of young adults with little or no education.

Before the outbreak, the three countries had only one to two doctors available to treat nearly 100,000 people. For comparison, Spain has 370 and the US has 245. That meagre workforce was further diminished as more than 800 health care workers contracted the disease and nearly 500 died.

This is the first big lesson. Well-functioning health systems need to be in place before a health crisis strikes. The best way to keep an outbreak from becoming an international threat is to stop it quickly at source.

Doing so requires a surveillance system that can pick up early signals of unusual disease events, response teams that can track and investigate cases, and laboratory services to support the investigation.

Of the 194 countries that are Member States of WHO, only 64, that is, less than a third, have these core capacities for outbreak alert and response in place. That is a shocking indictment of the state of global preparedness.

The virus affected an additional six countries in two groups. The US, Spain, and the UK reported cases, but their well-developed health systems gave the virus no chance to establish a foothold.

Senegal, Nigeria, and Mali had weak health systems but a high level of alert and preparedness, and treated the first imported cases as a national emergency. With support from their partners, all three countries defeated Ebola with very little, if any, onward transmission.

Ladies and gentlemen,

We learn more about the world’s vulnerability to emerging and re-emerging diseases when we look at how the outbreak started and subsequently spread.

Retrospective studies identify 26 December 2013 as the start of the outbreak, when an 18-month old boy living in a small village in Guinea’s Forest Zone fell ill and died two days later.

Much of the surrounding forest has been destroyed by foreign mining and timber operations. Some evidence suggests that disruption of the ancient forest ecology brought potentially infected wild animals, and the bat species thought to harbour the virus, into closer contact with human settlements.

Prior to symptom onset, the child was seen playing in his backyard near a hollow tree heavily infested with bats. This tells us something about the perils of environmental degradation.

From that initial case, the virus spread quickly, with fatal results, to other family members and the midwives, faith healers, and hospital staff who treated them, and then on to new villages as people travelled to attend funerals and then returned home.

The virus crept into the capital, Conakry, on 1 February and then fanned out further from the hospital where the patient was treated and died. No one knew this was Ebola. No one took any precautions.

A disease that killed so many so quickly did not go unnoticed. However, lack of capacity meant that the disease was first misdiagnosed as cholera and then later as Lassa fever, two of the many common infectious diseases that mimic the early symptoms of Ebola.

When the causative agent was finally identified on 21 March, the Ebola virus had been circulating, undetected and uncontained, in Guinea for nearly three months.

By then, the virus was firmly entrenched. A few scattered cases had already been imported into Liberia and Sierra Leone, but this spread, too, was silent and not detected until too late.

WHO had an investigative team on the ground in Guinea within days after the diagnosis was confirmed. But countries and their international partners, including WHO, underestimated the situation. We thought we knew Ebola. Knew how it behaved. Knew the course the disease would take. Knew how to control it.

This is another important lesson. Expect the unexpected. Never trust a virus to behave as it has in the past, especially when introduced into a new setting, with new opportunities to exploit.

The newness of Ebola added to the problems created by weak health systems. The three countries were poorly prepared for this unexpected and unfamiliar disease at every level.

Clinicians had never managed cases. No laboratory had ever diagnosed a patient specimen. No government had ever witnessed the social and economic upheaval that can accompany an outbreak of this disease. Populations could not understand what hit them or why.

The virus exploited exceptionally high population mobility across exceptionally porous borders, with the three countries persistently re-infecting each other. Populations readily cross borders, but response teams do not.

Throughout its history, Ebola had been largely a disease affecting remote rural areas where sparse populations created a natural barrier against explosive spread. In West Africa, the virus exploited urban environments and conditions in crowded slums.

But above all, the virus exploited West Africa’s deep-seated cultural traditions. Funeral and burial rites involving close contact with highly infectious corpses were the most dangerous of these traditions, and they proved highly resistant to change.

In Liberia and Sierra Leone, where burial rites are reinforced by a number of secret societies, some mourners bathe in or anoint others with rinse water from the washing of corpses.

In the face of early and persistent denial that Ebola was real, health messages issued to the public repeatedly emphasized that the disease was deadly, and had no vaccine, treatment, or cure. While intended to promote protective behaviours, these messages backfired.

If Western medicine had nothing to offer, families preferred to rely on traditional healers or care for loved ones in homes, thus giving the virus more opportunities to exploit.

Ebola preyed on another deep-seated cultural trait: compassion. In West Africa, the virus spread through the networks that bind societies together in a culture that stresses compassionate care for the ill and ceremonial care for their bodies if they die.

Apart from the need to invest in health systems, this is the second biggest lesson. The outbreak will never be brought to an end in the absence of full community engagement and cooperation. To this day, communities in Guinea and Sierra Leone continue to hide patients in homes, conduct secret unsafe burials at night, and refuse to cooperate with contact tracing teams.

Yet another lesson concerns the importance of creating incentives for the development of medical products for diseases that primarily affect the poor and thus have little market appeal.

Ebola has been known for nearly 40 years. Yet clinicians were left empty-handed, with no vaccines, treatments, or cures. I believe this lesson is already shaping events.

WHO has worked hard with industry to correct the R&D failure. New rapid diagnostic tests are coming on the market. Several promising drugs, including ZMapp, are currently undergoing clinical trials. The first phase III clinical trial of a vaccine began in Guinea over the weekend.

Ladies and gentlemen,

A review committee convened under the International Health Regulations to assess the response to the 2009 influenza pandemic concluded that the world was ill-prepared to cope with a severe and sustained disease event. Ebola was both.

When the outbreak peaked in the last quarter of 2014, everyone was overwhelmed. We had too little of everything.

Not enough treatment beds, laboratories, isolation wards, and ambulances. Not enough doctors and nurses, epidemiologists, logisticians, and burial teams. Not enough personal protective equipment, body bags, and space in cemeteries.

The world must never again find itself in such a position. Ebola has been a wake-up call, not just for Africa, but for the world. In my view, three changes will do the most to improve the world’s collective defence against the infectious disease threat.

First, invest in building resilient communities and well-performing health systems that integrate public health and primary health care. Ideally, health systems should aim for universal health coverage, so the poor are not left behind. This requires new thinking and a new approach to health development.

Second, develop the systems, capacities, and financing mechanisms needed to build surge capacity for responding to outbreaks and humanitarian emergencies.

Third, create incentives for R&D for new medical products for diseases that primarily affect the poor. A fair and just world should not let people die for what boils down to market failure and poverty.

These three things also fit well with the coming agenda for sustainable development that seeks to distribute the benefits of economic growth more evenly and respects our planet’s fragile resources.

From the health perspective, the greatest need is to have health systems in place that can withstand future shocks, whether these come from climate change or a runaway virus.

Doing so is not a luxury. It is the best insurance policy for the future and the best way to cement the tremendous gains in health made since the start of this century.

Thank you.