KINSHASA - The government of the Democratic Republic of the Congo (DRC) on Thursday declared a new outbreak of Ebola in the central province of Kasai, the country's 16th since 1976, as the World Health Organization (WHO) warned that infections might rise further.

DRC Health Minister Roger Kamba announced at a press conference in the capital of Kinshasa that the Zaire strain of the Ebola virus has re-emerged in the Bulape health zone, with 28 suspected cases reported, including 15 deaths. Four health workers were among the victims.

"These figures remain provisional, as investigations are still ongoing," Kamba said, stressing that the announcement was guided by transparency and scientific rigor.

Samples tested on Sept 3 at the DRC's National Institute of Biomedical Research confirmed the cause of the outbreak as the Zaire strain, the WHO Regional Office for Africa said in a statement. "Case numbers are likely to increase as the transmission is ongoing," it warned.

"The country has a stockpile of treatments, as well as 2,000 doses of the Ervebo Ebola vaccine, effective to protect against this type of Ebola, already prepositioned in Kinshasa that will be quickly moved to Kasai to vaccinate contacts and frontline health workers," the WHO noted, adding that it is delivering two tonnes of supplies, including personal protective equipment, mobile laboratory equipment and medical supplies.

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Meanwhile, it acknowledged that the affected area is hard to reach, taking at least one day of driving from the provincial capital Tshikapa, with few air links. "This is the starting phase of the response. We are too early to make an assessment," said Patrick Otim, an officer at the WHO regional office, at an online briefing.

According to an early statement by the Ministry of Health, the index case was a 34-year-old pregnant woman admitted to Bulape General Reference Hospital on Aug 20 with symptoms of sudden fever, multiple hemorrhages, bloody vomiting, and severe fatigue. She died on Aug 25 from multiple organ failure.

The DRC last declared the end of an Ebola outbreak in September 2022, after one case was confirmed in the eastern province of North Kivu. Testing showed that the case was genetically linked to the 2018-2020 outbreak in North Kivu and Ituri provinces, which killed nearly 2,300 people.

Kasai previously reported Ebola outbreaks in 2007 and 2008, according to the WHO.

Ebola first occurred in 1976 in two simultaneous outbreaks: one was of Sudan virus disease in Nzara in what is now South Sudan, and the other was of Ebola virus disease in Yambuku, in what is now the DRC, then known as Zaire. The latter occurred in a village near the Ebola River, from which the disease takes its name, according to the WHO.

Ebola is a highly contagious hemorrhagic fever that causes a range of symptoms such as fever, vomiting, diarrhea, generalized pain, or malaise, and in many cases, internal and external bleeding.