The World Health Organization on Sunday declared an Ebola outbreak in Congo and Uganda a ¡°public health emergency of international concern.¡±

The WHO said ?the ?outbreak, caused by the Bundibugyo virus, does not meet the ?criteria of a pandemic emergency but said countries sharing land borders with Congo are at high risk for further spread.

The U.N. health agency said in a statement ?that 80 suspected deaths, eight laboratory-confirmed cases and 246 suspected cases had been reported as of ?Saturday in Congo¡¯s Ituri province across at least three health zones, including Bunia, Rwampara and Mongbwalu.

Congo¡¯s health ?ministry had said on Friday ?that 80 people had died in the new outbreak in the eastern province.

The outbreak ¡ª the 17th in ?the country since Ebola was first identified ?there in 1976 ¡ª could be much larger, given the high positivity rate of the initial samples and increasing number of suspected cases being ?reported, the WHO said.

The ?outbreak is ¡°extraordinary¡± as there are no approved Bundibugyo virus-specific therapeutics or ?vaccines, unlike for Ebola-zaire strains, it said. All but one of the country¡¯s previous ?outbreaks were ?caused by the Zaire strain.

The Congo-Uganda outbreak poses a public health risk to other countries, with some such cases of an ?international spread already documented, the agency said, advising countries to activate their national disaster and emergency-management mechanisms and undertake cross-border screening and screening at main internal roads.

In Uganda¡¯s capital, Kampala, two apparently unrelated laboratory-confirmed cases, including one death, were reported on Friday and Saturday, from ?people ?traveling from Congo, the WHO said.

A laboratory-confirmed case was also ?reported in Congo¡¯s capital, Kinshasa, from a person returning from Ituri, the ?WHO said.

Bundibugyo virus-disease contacts or cases should not travel internationally, unless as part of a medical evacuation, the WHO said.

The agency advised immediately isolating confirmed cases and monitoring contacts daily, with restricted national travel and no international travel until ?21 days after exposure.

At the same time, the WHO urged countries not to close their borders or restrict travel and trade out of fear, as this could lead to people and goods making informal border crossings that are not monitored.

Congo¡¯s dense ?tropical forests are a natural reservoir for the Ebola virus.

The often-fatal virus, which causes fever, body aches, vomiting and diarrhea, spreads through direct contact with the bodily fluids of infected persons, contaminated materials or persons who have died from the disease, according to the Africa Centres for Disease Control and Prevention.