Ebola health care workers carry the body of a woman suspected of dying from Ebola, from a building used as a mortuary by the Bomi County Ebola Clinic on the outskirts of Monrovia, Liberia, Friday, Nov. 7, 2014. (Abbas Dulleh/AP)

Ban Ki-moon is secretary-general of the United Nations.

The Ebola outbreak is moving into a new phase that, in many ways, requires even greater attention and action than it has to this point. In addition to fears about the reach of the unforgiving virus and the spread of unfounded global panic, another concern has been added to the list: declaring “mission accomplished” too soon.

The rate of new Ebola cases shows encouraging signs of slowing in some of the hardest-hit parts of Liberia, Guinea and Sierra Leone — and that’s good news. The full-scale international strategy to attack Ebola through safe burials, treatment facilities and community mobilization is paying dividends.

But as caseloads go down in some areas, they are rising in others. Some of the worst-affected areas are now almost free of Ebola while neighboring districts are seeing numbers climb sharply. Beds may be empty in one facility while treatment centers are overflowing elsewhere.

The outbreak remains active. People are dying every day. New infections continue. And no one can say with certainty what the coming weeks might bring.

Recent history has proved that caseloads have risen and declined only to shoot up again. That is a familiar pattern of outbreaks. Meanwhile, we know that even one case can ignite an epidemic. A gap anywhere in the response leaves space for the virus to spread disease, kill people, destroy families and threaten the world.

The most effective way to neutralize the threat of Ebola is to end the outbreak at its source. The U.N. system is coming together with many partners in support of the affected countries. The U.N. Mission for Ebola Emergency Response — the first such emergency health mission — is galvanizing work on the front lines.

The short-term goal is clear: Rapidly isolate and treat 70 percent of new cases and ensure that at least 70 percent of burials are safe. This 70-70 strategy is the only way to break the exponential curve of infection.

The long-term goal is equally clear: zero cases in all countries. Getting there will require sustained hard work, resources and a commitment to address the underlying causes of the epidemic, most notably by strengthening health systems.

We are on the right track. Governments and communities in the region are combating the virus. Dozens of countries have stepped up with life-saving contributions. The United Nations is also partnering closely with regional organizations such as the European Union and the African Union, which is mobilizing medical professionals and health-care volunteers from throughout the continent. But huge gaps remain in funding, equipment and, most urgently, medical personnel.

There is no time to lose. What began as a public health emergency is now a complex crisis with profound social, economic, humanitarian, political and security dimensions.

Ebola is drawing oxygen away from businesses and basic services, driving up food prices, stigmatizing growing numbers of people, keeping children out of school and preventing pregnant women and those suffering from malaria and other diseases from accessing medical care. Household incomes across entire nations have declined by as much as one-third in six months.

Each day’s delay in intensifying the response adds greatly to the toll in lives, the cost of ending the outbreak, the social and economic impact, and the risk of the disease spreading to other countries.

Ebola will be beaten through a resolute and coordinated effort. We have initial evidence to prove that this can happen. But we must speed up efforts to first get the crisis under control and then bring it to an end.

Now is no time to let down our guard. We must keep fighting the fire until the last ember is out.