The Democratic Republic of Congo has confirmed 48 cases of Ebola and 31 deaths, the World Health Organization (WHO) said.

“It has been two weeks since the Government of the Congo declared an Ebola outbreak. So far, 48 confirmed and probable cases have been reported, and 31 people have died,” WHO Director-General Tedros Adhanom Ghebreyesus told reporters in Geneva.

He said the WHO had delivered more than 14 tons of essential medical supplies, deployed experts and set up an Ebola treatment center, where 16 patients are currently being treated.

More than 900 contacts have been identified and are being monitored, and the first two patients to recover were discharged on Tuesday.

The outbreak, the first in the country in three years, was declared in early September.

Congo’s dense tropical forests are a natural reservoir for the Ebola virus, which causes fever, body aches and diarrhea. The virus can remain in the bodies of survivors and re-emerge years later.

The WHO announced on Sunday that it had begun vaccinating frontline health workers and contacts of people infected with Ebola in the Kasai province of Congo.

The first 400 doses of the Ebola vaccine, out of a planned 2,000, have been delivered to the epicenter of the outbreak, in the town of Bulape.