Three people have died from an Ebola outbreak in a remote northern region of the Democratic Republic of Congo, as health officials travel to the central African country in response to a rising number of suspected cases, the World Health Organization says.

Last week, WHO reported one Ebola-related death and the possibility of two others. On Saturday, the organization confirmed the other two deaths were also Ebola-related.

The first case, which came April 22, involved a 45-year-old man. The taxi driver who took the man to the hospital and a person who cared for the man both became sick and later died, WHO said.

All three deaths came in the Likati health district of Bas-Uele province, which borders the Central African Republic.

Bas-Uele province, with a population of 900,000 in 2007, is mostly inhabited by the Boa tribe, which subsists through farming and hunting and conducts some trade by way of the Uele River.

Health officials are investigating 17 other suspected cases, Dr. Ernest Dabire, WHO’s health cluster coordinator, said Sunday in Kinshasa. He further estimated that 125 people had been linked to the confirmed Ebola cases and urged the public to be vigilant and visit their doctor if they experience fever or other symptoms.

Symptoms such as fever, headache, muscle pain, fatigue, diarrhea, vomiting, abdominal pain and hemorrhaging can begin two to 21 days after exposure.

Though the scope of the outbreak is not yet known, WHO is not recommending any restrictions on trade with or travel to DRC.

Ebola is a highly infectious virus spread through contact with bodily fluids, and testing shows the latest outbreak involves the Zaire strain, the most dangerous of the viruses known to cause the disease.

Background on the virus

A 2007 outbreak of this strain in Congo had a fatality rate of 74%, claiming 200 lives.

On Saturday, Dr. Matshidiso Moeti, WHO’s regional director for Africa, met with national authorities in Kinshasa to discuss ways to mount a response to the outbreak.

“WHO has already mobilized technical experts to be deployed on the ground and is ready to provide the leadership and technical expertise required to mount a coordinated and effective response,” Moeti said.

Three days prior, a team led by the DRC’s Health Ministry began the trek to the Likati health zone to begin an investigation. The 1,400-kilometer (870-mile) route from Kinshasa to Likati is remote and isolated with limited transportation networks, requiring two to three days of travel.

The team included epidemiologists, biologists and specialists in the areas of social mobilization, risk communication, community engagement and water, hygiene and sanitation, said Dr. Allarangar Yokouidé, a WHO representative.

There is no approved vaccine to prevent the virus, and there is no approved treatment or cure. Clinical trials of an experimental vaccine are ongoing in West Africa.

The US Centers for Disease Control and Prevention has been briefed on the outbreak and stands ready to provide epidemiological or laboratory support, if necessary, said spokeswoman Amy Rowland. The CDC has a team in the country working on a monkeypox vaccine trial, she said.

Médecins Sans Frontières, the United Nations Children’s Fund and other international organizations are standing by as well, WHO said last week.

Rowland pointed out that DRC has extensive experience with Ebola, this being the country’s eighth outbreak since the virus was discovered near the Ebola River in 1976.

The last outbreak in 2014 in DRC’s Boende region — an event unrelated to the 2014 West Africa outbreak that killed thousands — was short-lived, as a team of field epidemiologists quickly stopped the spread of the disease, limiting it to 66 cases, 49 of them fatal.

These “disease detectives” are in a good position to help with the current outbreak, Rowland said.

Aside from the 1976 outbreak in DRC, which killed 280 people in Yambuku, the deadliest outbreak came in 1995, when Ebola killed 250 people in Kikwit.

Are concerns of a global pandemic founded?

In 2014, more than 11,300 people were killed in the worst-ever outbreak of the virus in West Africa, most of them in Guinea, Sierra Leone and Liberia. During that outbreak, which WHO declared a “public health emergency of international concern,” the Western Hemisphere also saw its first Ebola patients.

Seven Americans who had been working in Africa became infected and were transported to the United States for treatment. In addition, two American nurses were infected after caring for a Liberian man who died from the virus in the hospital where they worked in Texas.

-CNN