Ebola outbreak
A woman walks past garbage near shops on a street in Conakry, where about 20 people were confirmed infected. Reuters

The World Health Organization has called the ongoing Ebola outbreak in West Africa as "one of the most challenging" health workers have ever encountered.

The disease has claimed 111 lives in the region, even as about 178 people are confirmed infected in Guinea and Liberia, according to The Star.

WHO raised concerns over the inefficient medical infrastructure to deal with the epidemic, which is new to western Africa.

"We have not had an Ebola outbreak in this part of Africa before," Keiji Fukuda, assistant director-general at WHO, told AFP.

The most virulent strains of the virus have a fatality rate of 90%, while this outbreak has claimed over two-thirds of the infected patients.

So far, 101 people have died of the disease in Guinea while 10 people succumbed to the lethal virus in Liberia.

About 20 of the cases in Guinea were reported from the capital city of Conakry with a population of over 1.5 million.

There is no known cure or vaccine for the virus but treatment involves supportive care through rehydration, nutrition and pain relief to improve the chances of survival.

The Ebola vector is highly contagious and passes through body fluids of the infected people or animals, which makes it vital to quarantine the patients and to put in place a reliable monitoring mechanism to screen for the remotest signs of the disease.

Other countries in Africa are on guard to spot and quarantine suspected cases without delay.

Senegal shuts border with Guinea

Two suspected cases were reported in Sierra Leone, one of whom died in an isolation ward. Senegal has closed its border with Guinea and has not recorded any Ebola case so far.

"We have everything in place to take measures against Ebola. We have a well-oiled system, which we are perfecting daily," Eva Marie Coll Seck, Senegal's health minister, was quoted as saying by AFP.

"Obviously there is a risk that other countries might be affected, therefore we absolutely need to remain vigilant," said Stephane Hugonnet, a WHO medical officer.

"Clearly in Guinea Forestiere the outbreak is not over. This is the epicentre of the outbreak, and as long as this is not controlled there, there may be cases being exported from Guinea Forestiere in the rest of the country and likely in other countries."

Mali has confirmed the Ebola virus in seven out of nine suspected patients, but one suspected case in Ghana was ruled negative.

Meanwhile, at least seven infected patients in Guinea were reported to have recovered from the virus.

"When the first patient came out from the treatment centre, I was so happy and the whole team was cheering," Dr Marie-Claire Lamah from Medecins Sans Frontieres in Conakry told the BBC.

MSF spokesperson Sam Taylor expressed his delight at seeing patients hale and hearty again and out of the clutches of the deadly disease.

"... you can hold their hand and see that they are totally fine, it improves everyone's morale and it's great news for the families and the communities these people are going back to," he said.

Uganda witnessed the largest-known Ebola epidemic in 2000, when about 224 people died out of a total of 425 confirmed infected patients.

The disease originated in the Democratic Republic of Congo in 1976, and the last recorded Ebola outbreak prior to Guinea was reported from the same country in 2012 when about 29 people died of the virus.