Before 2014, it seemed unimaginable to many experts that Ebola would rip through dense urban areas, ultimately sickening nearly 30,000 people and killing more than 13,000.1 Four years later, Ebola is again spreading in urban areas, this time in the Democratic Republic of Congo (DRC). Though there are clear signs that global preparedness for epidemics has been strengthened, efforts to contain the DRC outbreak have not been sufficient. Additional human and financial resources are needed to prevent this outbreak from becoming a major epidemic.

There are several strengths and capabilities in the DRC that were not available to the Ebola response in West Africa in 2014: the DRC has experience in containing Ebola outbreaks; a new investigational Ebola vaccine has been administered to more than 24,000 people2; and the World Health Organization (WHO) is playing a strong leadership and operational role in confronting the outbreak.

Yet efforts to stop the spread of disease haven’t succeeded. Since September, the incidence of Ebola has more than doubled, according to WHO situation reports. The majority of people with recently identified Ebola were not on existing lists of contacts of people with previously identified cases — which indicates a high degree of unrecognized transmission in the community. The virus has spread to 11 DRC health zones, and the WHO has deemed the risk of further regional spread to be very high. There has been some breakdown in disease-control efforts because of security conflicts. In one of the epicenters of the outbreak, Beni, response was interrupted after armed civil conflict and a community-wide strike that followed it. As in previous Ebola outbreaks, some containment efforts have also encountered community resistance.

The WHO recently convened an emergency committee to determine whether the outbreak should be declared a Public Health Emergency of International Concern (PHEIC) — a designation applied to only four past outbreaks. The committee decided that the outbreak did not yet constitute a PHEIC but said that it “remains deeply concerned by the outbreak and emphasized that the response activities need to be intensified” and that otherwise the situation is likely to “deteriorate significantly.”3 Given the rapidly growing case numbers, limited ability in the field to conduct contact investigations, and high potential for cross-border spread, we believe that declaration of a PHEIC seems warranted now. It would increase both political attention and the financial resources flowing to the control effort. But leaders need not wait for such a declaration before they deepen their commitments: in recognizing the urgency of the concern expressed by the emergency committee, they can act now.

Containment is not possible without bolstering efforts to detect all cases, conduct thorough case investigations, monitor case contacts, and rapidly isolate anyone with symptoms. Tracking down case contacts is also essential for supporting ongoing ring-vaccination efforts. Another urgent need is for enhanced infection-control protections at health facilities, which have become an important locus of transmission. More than 10% of Ebola cases have occurred in health workers. Vaccinating health workers, strengthening infection-control practices, and increasing workers’ capacity to recognize and report potential cases of Ebola are all essential.

At this point, “intensified” efforts, as requested by the emergency committee, will require additional seasoned responders with cultural competency, including local language skills, technical expertise, and experience in managing complex outbreaks. Given the highly dynamic nature of this outbreak, additional experienced personnel are needed in the field to lead response operations and develop and implement strategies as dictated by changing information. Though some case-investigation activities are ongoing, the high proportion of Ebola cases being discovered among people not on existing contact lists or in people with previously undiagnosed illness dying in the community indicates that additional leaders with deep experience are needed to oversee field teams to improve the capability and reach of existing efforts.

Since 1976, the Centers for Disease Control and Prevention (CDC) has responded to more than 20 filovirus outbreaks, including Ebola in West Africa, and has requisite experience in working in outbreak settings where there is community opposition to disease-control measures. As a result, CDC personnel understand what it takes to control dangerous infectious diseases in complex environments. CDC staff were recently pulled from the field in the DRC owing to U.S. government concerns about security. Given the worsening of the outbreak, we believe it’s essential that these security concerns be addressed and that CDC staff return to the field.

With the reports of violence in the DRC, it may seem impossible to increase Ebola response efforts. But hundreds of responders are already in the field and have generally been able to operate safely in the area. The WHO has more than 250 staff deployed. Many other organizations have sent staff, including some who are American citizens.

Though there are risks in sending additional personnel to the DRC, high risks would also be posed by an outbreak spiraling out of control. The World Bank estimates that the West Africa epidemic cost the three affected countries $2.2 billion in lost gross domestic product in 2015. The U.S. government sent thousands of personnel to the region and spent more than $5 billion responding to that epidemic.4 Though the current outbreak doesn’t yet match the scale of the West Africa epidemic, its trajectory thus far and the underlying conditions in the DRC are cause for worry. North Kivu is home to more than 6 million people, including more than 1 million internally displaced people. If the outbreak goes unchecked, it could threaten the health and stability of neighboring countries: Uganda, Rwanda, and South Sudan. Such spread would lead to travel, trade, economic, and security implications reaching far beyond the region, which would exacerbate the toll of the outbreak and increase the cost of response. It is hard to imagine that the U.S. government would not, in such a case, have to deploy substantial numbers of health and security personnel, as it did in 2014.

We therefore believe that the U.S. government should allow CDC staff to return to the field for as long as the WHO and others deem necessary. Security arrangements should be made to ensure that any deployed teams could operate safely in affected areas. Options for the safe deployment of CDC personnel may include using existing security forces, such as the United Nations Organization Stabilization Mission in the DR Congo (MONUSCO), which is currently protecting WHO staff. Ideally, epidemic response agencies and organizations from other countries with Ebola experience that are not already engaged in the current response would similarly offer assistance to the WHO and the DRC.

The WHO has transformed its ability to respond to emergencies, but it remains dependent on international support, both technical and financial. It has requested that member states create a Contingency Fund for Emergencies (CFE) to support its work in responding to disease and other crises. To date, however, the CFE has received less than a third of its $100 million annual target. More support is clearly needed; it’s estimated that the response to the DRC Ebola outbreak alone will cost $44 million.5

If we do not act now, the outbreak may become far harder and more expensive to stop. After the West Africa epidemic, the United States and other countries made investments to help reform the WHO to enable it to play a more operational and coordinating role during epidemics. But the WHO, the DRC, and local partners won’t be able to succeed without sufficient human and financial resources.