(CNN) A second person has died after contracting Ebola in Goma, a major transit hub in the Democratic Republic of Congo on the Rwandan border, according to Médecins Sans Frontières (MSF).

The patient died Wednesday, around 26 hours after being admitted to an MSF-supported Ebola treatment center, the organization said on Twitter

World Health Organization (WHO) officials have feared Ebola's arrival in the city for months. Goma is home to a highly mobile population of more than 1 million, which makes the risk of the disease spreading high.

"This is an event we have anticipated. This is why we have been doing intensive preparedness work in Goma so that any new case is identified and responded to immediately," Tedros Adhanom Ghebreyesus, the WHO's director general, said on Twitter.

More than 5,000 health workers have been vaccinated against Ebola in the city and health centers have been provided with training and equipment to improve infection prevention and control, he said.

Screenings at border crossings have been reinforced and 24-hour monitoring has been implemented at the airport, Ghebreyesus added.

WHO declared the latest Ebola outbreak a Health Emergency of International Concern on June 17, a day after the first person diagnosed in Goma died. That patient was a pastor who had left South Kivu to evangelize in Butembo, a center of the current Ebola outbreak.

Ghebreyesus said there was no indication that the second victim was linked to the first case.

The latest victim was described by WHO officials as a 46-year-old miner who had been working in the Ituri province, north of Goma. He developed Ebola symptoms after returning home earlier this month, Margaret Harris, a WHO spokeswoman in Goma, told CNN Wednesday by telephone.

Health investigators were not able to interview the man before he died because he was so ill when he was admitted, Harris said. Investigators are now trying to track the man's movements to identify where he contracted the disease and who may have been exposed.

"We are assuming on his way to Goma he passed through an area of transmission," Harris said.

The man's family members have been vaccinated against Ebola, and they are being monitored by medical personnel who are conducting daily checks, she said

"He was in the community symptomatic for a good period of time, for much longer than we want to see people out there," Harris said.

Jean-Jacques Muyembe Tamfum, head of the national research institute and head of the national Ebola response teams, said during a Tuesday press conference that workers had been deployed to disinfect the victim's home and the health center he passed through.

"We have already established a list of high-risk contacts and as early as [Wednesday] we will start to compile a list of contacts, and ... these contacts will be vaccinated," he said.

The rare but deadly Ebola virus disease can cause fever, headache, muscle pain, vomiting, diarrhea and unexplained bleeding, among other symptoms. The virus was first identified in 1976 when outbreaks occurred near the Ebola River in the DRC.

Scientists think the virus initially infected humans through close contact with an infected animal , such as a bat, and then the virus spread from person to person.

The virus spreads between humans through direct contact with an infected person's bodily fluids, including infected blood, feces or vomit, or direct contact with contaminated objects, such as needles and syringes.

The current Ebola outbreak in the DRC is the second-deadliest in history, topped only by one in West Africa in 2014, when the disease killed more than 11,000 people, according to the WHO.

To mark Thursday's first anniversary of the current outbreak being declared, UN agencies issued a joint statement on Wednesday, saying there have been more than 2,600 confirmed cases, including more than 1,800 deaths, in parts of DRC's Ituri and North Kivu provinces.

"Almost one in three 'cases' is a child," the agencies said in the statement.

Correction: This article has been revised to reflect that Tamfum leads the national Ebola response team, not WHO's Ebola response team.