KINSHASA, Aug. 10 (Xinhua) -- The Ebola outbreak in the Democratic Republic of the Congo (DRC) may have begun as early as February, months before it was officially declared in May, according to genetic sequencing studies, a senior World Health Organization (WHO) official said Monday.
Speaking at a press conference in Bunia, capital of the eastern Ituri Province and the epicenter of the outbreak, WHO Regional Director for Africa Mohamed Yakub Janabi said genetic sequencing indicated that the virus had likely been circulating for months before the outbreak was detected.
The DRC officially declared outbreaks of Ebola disease caused by the Bundibugyo virus on May 15.
According to the latest figures released by local authorities, the DRC had recorded 4,209 confirmed cases, including 1,916 deaths, as of Aug. 7. Cases have been reported in Ituri, North Kivu, South Kivu, Haut-Uele, and Tshopo provinces in the country's east.
"We are chasing the virus. The virus is ahead of us," Janabi said, pointing to the prolonged period during which transmission may have gone undetected.
Some infections during the early phase of the outbreak may have initially been attributed to other illnesses, including malaria and typhoid, contributing to delays in recognizing the extent of Ebola transmission, Janabi said, warning of prolonged undetected circulation.
He also noted that the virus is spreading faster than initially anticipated, while the current outbreak differs from previous outbreaks caused by the Bundibugyo virus in Uganda in 2007 and the DRC in 2012.
Meanwhile, the response teams are still detecting only a fraction of infections early enough, Janabi said, adding that around 60 to 70 percent of deaths were reported outside the treatment centers.
On Aug. 7, a WHO technical advisory group recommended that the Ervebo vaccine be prioritized for inclusion in a randomized clinical trial in the context of the ongoing outbreak.
Marie Roseline Belizaire, a WHO expert, said that research suggested the possibility of cross-protection, and discussions are underway on clinical studies to assess whether the vaccine could provide protection against the Bundibugyo virus in humans.
WHO Representative in the DRC Anne Ancia said that a large population in North Kivu got vaccinated with Ervebo during the country's 2018-2020 Ebola outbreak.
Information showed that previously vaccinated health workers infected with the Bundibugyo virus during the current outbreak survived and appeared to develop milder illness, she said, suggesting a possible cross-protective effect that still needs to be confirmed through further studies.
Janabi said stronger community participation, earlier case detection, and decentralized treatment would be critical to changing the trajectory of the outbreak over the coming eight to 12 weeks.
The current outbreak is the 17th Ebola outbreak in the DRC. It is now the country's largest on record and the second-largest Ebola outbreak globally, only behind the 2014-2016 West Africa epidemic. ■