An Ebola outbreak that has resulted in at least 131 fatalities in the Democratic Republic of Congo may be spreading faster than initially estimated, warned a representative from the World Health Organization (WHO).

Dr. Anne Ancia informed the BBC that ongoing investigations reveal a concerning increase in the spread of cases to various regions.

As reported on Tuesday, over 513 suspected cases of Ebola have emerged in DR Congo, alongside one casualty in neighboring Uganda.

Modelling conducted by the MRC Centre for Global Infectious Disease Analysis in London has indicated significant under-reporting, suggesting that the actual number of cases could surpass 1,000.

WHO director Tedros Adhanom Ghebreyesus expressed his deep concerns over the scale and rapid acceleration of the epidemic, which was declared an international emergency just last week.

It is feared that the outbreak occurred weeks before it was officially detected on April 24.

Currently, no effective vaccine exists for the strain of the Ebola virus responsible for this outbreak, though WHO is exploring potential treatments.

During an interview with BBC World Service Newsday, Ancia pointed out that DR Congo's Ituri province, the outbreak's epicenter, presents security challenges and a high population turnover, complicating containment efforts.

She elaborated, The more we investigate this outbreak, the more we understand that it has already disseminated to neighboring areas and other provinces.

The outbreak has also reached South Kivu province, an area grappling with an extended humanitarian crisis. Additionally, a case has been confirmed in Goma, DR Congo's largest city, known for having a population of around 850,000, which is governed by insurgents.

Insecurity in several provinces is contributing to population movement, raising the risk and transmission of the virus.

As a precaution, several African nations have heightened border screenings and prepared local health facilities. Neighbouring Rwanda has closed its borders with DR Congo as a protective measure.

An American national, reportedly a member of a missionary group, is in the process of being evacuated from DR Congo after showing symptoms indicative of Ebola.

Germany's health ministry confirmed that this individual is being transported for medical treatment.

The CDC is also coordinating the evacuation of at least six other Americans who may have been exposed to the virus.

Ebola is viral in origin and initially presents with flu-like symptoms, including fever, headache, and fatigue. The particular strain driving the recent surge in cases is rare and has previously caused only two outbreaks, with a lethality rate of about one-third for those infected.

From 2014 to 2016, the largest Ebola outbreak occurred in West Africa, infecting over 28,600 individuals and leading to 11,325 deaths across multiple countries.