At least 680 people have been infected with the Ebola virus in the Democratic Republic of Congo. It’s the second-largest Ebola outbreak in history, with 414 deaths so far, and the first Ebola outbreak in an active war zone. But it could get worse: Health officials this week are concerned that Ebola appears to be spreading in the direction of Goma, a major population center in DRC.

So far, the outbreak has not affected DRC’s biggest cities. But Ebola in Kayina “raises the alarm” for Ebola reaching Goma, Peter Salama, the head of the new Health Emergencies Program at the World Health Organization, told Vox.

Goma is a major transportation hub, with roads and highways that lead to Rwanda. “These are crossroad cities and market towns,” Salama added. People there are constantly on the move doing business, and also because of the insecurity in North Kivu. Ebola in Goma is a nightmare scenario WHO and DRC’s health ministry are scrambling to prevent.

Together, they’ve deployed a rapid response team, including a vaccination team, to Kayina. And if the virus moves on to Goma, Salama says Ebola responders are ready. They’ve already mobilized teams there, set up a lab, and prepared health centers where sick people can be cared for in isolation.

An Ebola vaccine has been no match for DRC’s social and political chaos

When Ebola strikes, it’s like the worst and most humiliating flu you could imagine. People get the sweats, along with body aches and pains. Then they start vomiting and having uncontrollable diarrhea. They experience dehydration. These symptoms can appear anywhere between two and 21 days after exposure to the virus. Sometimes patients go into shock. In rare cases, they bleed.

They also employ a strategy called “contact tracing”: finding all the contacts of people who are sick, and following up with them for 21 days — the period during which Ebola incubates.“The brutality of the conflict is shocking,” Jan Egeland, head of the Norwegian Refugee Council, told the Thomson Reuters Foundation, “the national and international neglect outrageous.”

 “Many people would have been extremely skeptical that the outbreak in Beni could be controlled as quickly given force of infection we were seeing in November and December, and the fact that we’ve had nothing but volatility and insecurity since then,” Salama said. “But the fact that Beni has had only one confirmed case in two weeks is giving us a lot of hope and optimism.”