This article originally appeared at BBC.
The World Health Organization has said the speed and extent of the Ebola outbreak in West Africa is “unprecedented”.
The WHO’s Dr Keiji Fukuda expressed concern over so-called “shadow zones”, areas which cannot be reached and where patients are not being detected.
The organisation confirmed 142 new cases of the disease had been reported since 19 August, as well as 77 deaths.
Already more people have died in this outbreak of Ebola than in any other.
At least 1,427 people have now died in the outbreak so far, with the number of cases now standing at 2,615.
Speaking at a news conference in the Liberian capital Monrovia, Dr Fukuda said combating the disease would take “several months of hard work”.
“We haven’t seen an Ebola outbreak covering towns, rural areas so quickly and over such a wide area,” he added.
Also on Friday, Nigerian authorities said that they had detected two new cases of the virus, both spouses of medical workers who had direct contact with a man who died from the virus in Nigeria after arriving from Liberia.
In Liberia on Friday, a boy of 16 shot during a protest about a quarantine died.
Shakie Kamara was one of three people seriously injured on Wednesday after security forces fired at protesters, angry after blockades were erected around the West Point slum.