Boots hang out to dry in a camp set up by health workers in Tana, Guinea, to fight against the last cases of Ebola there. Credit: Samuel Aranda/Panos

Update, 15 January: After this article was published, a death from Ebola was announced in Sierra Leone – underlining, as health officials have emphasized, the potential for new cases of the virus to emerge.

After the deaths of more than 11,000 people, public-health officials declared on 14 January that the spread of Ebola in West Africa has been stopped — at least for now.

Officials with the World Health Organization (WHO) said that no new cases have been detected in Liberia since December. Since Sierra Leone and Guinea have already been declared Ebola-free, this officially ends the chain of human transmission in the region that began more than two years ago.

“Detecting and breaking every chain of transmission has been a monumental achievement,” said WHO director-general Margaret Chan. But the epidemic may not be over for good. The WHO cautioned that the virus could re-emerge, as happened twice in flare-ups in Liberia after the country was first declared Ebola-free last May.

The epidemic has been one of the worst international health disasters in history: unprecedented in its duration as well as the number of people it infected and killed. Here are seven lessons that health officials and the world at large have learned from the harrowing event.

1. The world isn’t equipped to deal with international public-health crises, especially in poor countries.

The epidemic emerged in Guinea in December 2013, then grew out of control as local and foreign governments and the WHO failed to contain it or devote adequate resources to stopping it. Although numerous global panels of experts have called for reform, there has been little movement towards fixing the broken international health systems whose failure led to the problem.

2. The balance of power in global health has shifted.

The WHO acknowledges its own failings on Ebola, which demonstrated how the organization was unable to respond quickly to fast-moving epidemics in developing countries. In fighting the West Africa epidemic, non-governmental organizations — including local groups, religious charities and the international health-aid organization Médecins Sans Frontières (also known as Doctors Without Borders) — shouldered much of the burden.

3. West Africa's medical infrastructure is extremely shaky.

A few dedicated local health workers fought valiantly against Ebola when it first emerged, but they had too few resources to do the job. Many who fought the disease lost their lives, compounding the problem. And the epidemic is likely to have long-lasting impacts on health in West Africa — for instance, by diverting resources away from fragile gains in maternal and child health, orphaning children and causing lingering medical problems in survivors. Ebola and other viral threats are likely to re-emerge, underscoring the importance of shoring up resources in the region.

4. Stigma and fear can fuel an already deadly epidemic.

Early misconceptions that Ebola was always fatal and impossible to treat kept people from seeking treatment, allowing the disease to spread in communities. And a dearth of clear communication about how to contain the virus and safely care for the sick drove its spread among those brave and loyal enough to care for loved ones. Survivors are among the most valuable workers against Ebola, because they are thought to have some immunity to the virus, but in many places they have been ostracized from their communities.

Countries outside Africa compounded irrational fear by clamping down on international travel and quarantining returning health-workers; the state of Louisiana even banned scientists who had worked to combat the virus from attending a meeting.

5. Beating Ebola required officials to understand the local culture and let the region’s leaders lead.

Efforts by foreign countries often collided with realities on the ground, contributing to the spread of the disease. The lack of a word for ‘virus’ in some local languages, for instance, caused confusion; people chafed at travel bans and quarantines; and many families balked at sending their loves ones to distant treatment centres.

Informed local leaders, such as chiefs and religious leaders, educated communities more effectively than well-intentioned foreign experts.

6. Clinical trials need to happen even faster in the next epidemic.

Scientific leaders and health officials organized faster than ever before to test candidate Ebola drugs and vaccines during the epidemic, and were able to prove that one vaccine is effective. But bureaucratic delays and infighting stalled many trials until the epidemic had largely passed its peak, so there are still no definitive results on whether experimental treatments such as the drug ZMapp actually work.

7. It isn't over yet.

Before this epidemic, few thought that an Ebola outbreak could grow to this scale. But increasing urbanization and connectivity have changed the dynamic of this and other emerging infectious diseases. Officials hope to beef up disease surveillance in West Africa, but they still don’t even know for certain which animals harbour Ebola in the wild, so it is difficult to predict where or when the next outbreak will occur.

And there are other lethal viruses that could cause as much suffering as Ebola has in West Africa, or even more. This outbreak has demonstrated that the world is much more vulnerable to global epidemics than anyone realized two years ago.