According to the WHO, the recent Ebola outbreak in the Democratic Republic of Congo and Uganda is now considered a public health emergency of international concern.
Officials say there have been several suspected deaths with the exact scope of the outbreak not yet fully known.
WHO Director General Tedros Adhanom Ghebreyesus made the declaration on Sunday, saying that there were increasing numbers of cases and cross border transmission, as well as major surveillance gaps.
Ghebreyesus added that this did not mean a pandemic level state of emergency and that neighboring nations should not close their borders and limit commerce because of it.
This epidemic is caused by a rare virus known as Bundibugyo, which had caused a reported outbreak only two times before.
There is currently no vaccine and no specific treatment for the disease; furthermore, rapid tests normally used to detect it may miss it.
Fatality rates of Bundibugyo have been in the area of about 25% to 40%, significantly below the average rate of 50% for all forms of Ebola.
The outbreak was first reported by health authorities late last week in Ituri province in eastern DRC, near the borders with Uganda and South Sudan.
By Saturday, the Africa Centres for Disease Control and Prevention had recorded more than 330 suspected cases and at least 87 deaths, including four health care workers.
A woman who travelled to the major eastern city of Goma, held by the Rwanda backed M23 militia, from Bunia after her husband died of the virus has since been confirmed by a laboratory.
In another case, a 59 year old man from Congo died on arrival in Uganda’s capital of Kampala, alarming authorities there.
Contact tracers are still trying to trace everybody he came into contact with before he died.
“Given the magnitude of cases and deaths seen within such a short time period, as well as the extent of spread in different health zones and also across the border to Uganda, it is very alarming”.
The WHO noted that the true scale of the epidemic was likely to be much greater than the numbers currently reported, noting that many cases were positive based on earlier samples and that there have been clusters of mysterious deaths in affected regions.
The WHO has asked both the DRC and Uganda to implement their respective disaster plans, step up contact tracing efforts and improve hygiene controls at hospitals, especially with respect to the lack of personal protective equipment.
More than 30 staff from the United States CDC have arrived in the DRC, while others will join them in the next few days.
A handful of Americans known to have been exposed to suspected cases will soon leave the country.
One experimental vaccine candidate developed at the US National Institute of Allergy and Infectious Diseases has shown efficacy of about 50% in primate trials, but has not been tested in humans.
