A case of Ebola has reached the city of Goma in the Democratic Republic of the Congo (DRC), and the World Health Organization (WHO) warned Monday that its arrival could drastically impact the virus’ ability to spread.

Goma borders Rwanda and has a population of 2 million people. It is also a transport hub for central Africa, which is what makes the newly reported case so alarming.

The patient, a pastor, arrived in Goma by bus Sunday. He visited a regional centre and was quickly moved to an Ebola treatment centre, according to the DRC health ministry.

He died while being transported from Goma to a clinic in Butembo on Monday, according to North Kivu province’s governor Carly Nzanzu.

There are checkpoints between Butembo and Goma, but if a person shows no symptoms, they are not effective.

“The case in Goma could potentially be a game changer in this epidemic,” WHO Director-General Tedros Adhanom Ghebreyesus said at a high-level meeting in Geneva. “It is a gateway to the region and the world.”

Health officials have identified 60 people who were in contact with the pastor since he became sick, and half of them have been vaccinated, the WHO reported.

“Because of the speed with which the patient was identified and isolated, and the identification of all the other bus passengers coming from Butembo, the risk of it spreading in the rest of the city of Goma is small,” the DRC health ministry said.

Still, keeping it contained is vital to preventing a large-scale outbreak.

“This Ebola epidemic has now reached close to Rwanda. There is a need to be more vigilant and to avoid unnecessary visits to Goma,” Diane Gashumba, Rwanda’s health minister, said.

This outbreak has seen more than 2,500 cases (2,407 confirmed, 94 probable) — 1,700 people have died (1,574 confirmed due to Ebola, 94 probable), according to the most recent data.

Ebola is a highly infectious virus, and while this outbreak has been kept contained due to health initiatives and an experimental vaccine, the fear of it spreading is all too real.

The current outbreak is particularly difficult to address, as health workers are struggling to access people in need of care and vaccines in conflict-ridden areas. There is also the issue of misinformation about the disease and public mistrust of authorities.