KINSHASA, May 18 (Xinhua) -- The Democratic Republic of the Congo must quickly strengthen active surveillance, trace transmission chains and prevent the Ebola virus from spreading after the latest outbreak in the country, a leading Congolese virologist has warned.

Jean-Jacques Muyembe, director general of the National Institute of Biomedical Research, told Xinhua on Sunday that the immediate response should rely on core public health measures like isolating patients, carrying out active surveillance, tracing contacts, protecting health workers and disinfecting health facilities.

The outbreak in the eastern province of Ituri is caused by the Bundibugyo strain, a rare variant of the Ebola disease that has no approved therapeutics or vaccines.

RARE STRAIN

Congolese health authorities declared the new Ebola outbreak in Ituri on Friday, the country's 17th since 1976. According to data released Saturday by the Africa Centers for Disease Control and Prevention (Africa CDC), 336 cases and 87 deaths have been reported.

Muyembe said the current outbreak was not caused by the more familiar Ebola Zaire strain, but by the Bundibugyo strain, which was first identified in Uganda in 2007 and later caused an Ebola outbreak in 2012.

Of the 17 Ebola outbreaks recorded in the country, 15 were caused by the Zaire strain and two by the Bundibugyo strain, he said.

The main difference, Muyembe said, is pathogenicity. The Zaire strain is among the most virulent forms of Ebola and can have a fatality rate of around 80 percent or higher, while the Bundibugyo strain has a fatality rate below 50 percent.

HEIGHTENED RISKS

Muyembe said the current outbreak spread to multiple areas in Ituri. The risk of further transmission is especially high in eastern Congo because of population density, frequent movement and the challenges of managing an epidemic in a conflict zone, he said.

"The risk that the virus escapes these health zones and spreads to other health zones, or even to other provinces, is very great," he said.

A confirmed case has also been reported in Goma, the capital of North Kivu province. The city, currently under the control of the March 23 Movement rebel group, lies on the border with Rwanda and is a major urban and cross-border hub.

After the case was confirmed in Goma, Rwanda temporarily closed border posts with the city. Muyembe said that under the International Health Regulations, the response to Ebola should be strengthening cross-border health coordination, screening and contact tracing, instead of closing borders.

PUBLIC HEALTH RESPONSE MATTERS

The Africa CDC has said there is currently no specific vaccine or treatment for the Bundibugyo strain. Muyembe said research is continuing to assess possible vaccine candidates and medical options that could be used against it.

He noted that the 2012 Ebola outbreak, also caused by the strain, was controlled through public health measures.

"For those who are hospitalized and sick, we have standard care techniques. By applying them, we stop the outbreak," he said.

Depicting health as a matter of sovereignty, Muyembe said that while partners could provide support, it was ultimately up to the government to take charge and establish mechanisms to detect outbreaks as quickly as possible and mount an effective response.