NEW YORK – Defying efforts at containment, the Ebola outbreak that began in Guinea and has caused 90 dead in Guinea and Liberia has now spread further across West Africa into Mali in what Doctors without Borders is calling an “unprecedented” outbreak.

The U.N.’s World Health Organization, or WHO, has identified the active virus as the Zaire strain of Ebola. The virus has a death rate approaching 90 percent, suggesting that unless contained, the outbreak in West Africa could become one of deadliest epidemics of Ebola, for which there is no known cure.

Doctors without Borders has 52 international staff working alongside its Guinea staff in cooperation with Guinea’s Ministry of Health.

The group is caring for 19 patents held in isolation units set up in various locations across Guinea.

The teams include doctors, nurses, epidemiologists, water and sanitation experts, health promoters and psychologists.

“Our efforts are aimed at containing the outbreak, which is accomplished by detection of the sick and isolating them from the rest of the population,” explained Anja Wolz, MSF’s emergency coordinator in Conakry, Guinea.

“Although there is no cure for this disease, we can reduce its very high mortality by addressing the symptoms. This includes administering a drip to patients who have become dehydrated from diarrhea and by confirming that they do not have a different disease, such as malaria or a bacterial infection like typhoid.”

Meanwhile, tensions in the region are growing as health-care authorities fight to combat panic in the areas affected by the Ebola outbreak.

In Mali, three people have been placed in quarantine, with samples sent off to the Centers for Disease Control and Prevention in Atlanta for testing.

The Associated Press reported Friday that residents in Bamako, the capital of Mali, have conducted public demonstrations that resulted in several people wounded when police tried to disperse protesters.

The crowds in Bamako were evidently angry that several people suspected of having the deadly disease were being held in isolation in their neighborhood.

Also on Friday, an angry mob attacked an Ebola treatment center in Guinea, accusing the staff of bring the disease to the town, according to Reuters.

“We have evacuated all our staff and closed the treatment center,” Doctors without Borders medical worker Sam Taylor told Reuters, declining to give details of the attack. “We have the full support of the local leaders and we’re working with the authorities to try and resolve this problem as quickly as possible so we can start treating people again.”

Government health officials in Guinea have banned the consumption of bat and bush meat, local delicacies in West African nations that are considered carriers of the Ebola virus.

Last week, Senegal closed its border with Guinea in an attempt to stop the spread of the virus.

WHO reports Ebola first appeared in 1976 in two simultaneous outbreaks, in Nzara, Sudan, and in a village in Yambuku, Democratic Republic of Congo, situated near the Ebola River, from which the disease takes its name.

“Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals,” the WHO website says.

“In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found dead or ill in the rainforest.”

Ebola spreads from close contact with the blood, secretions, organs or other bodily fluids of infected people.

WHO warns burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in the transmission of Ebola. The transmission of the disease via infected semen can occur up to seven weeks after clinical recovery.

Dr. Peter Piot, co-discoverer of the Ebola virus

The Centers for Disease Control and Prevention warn the symptoms of Ebola include fever, headache, joint and muscle aches, weakness, diarrhea, vomiting, stomach pain and lack of appetite, while some patients also experience a rash, red eyes, hiccups, cough, sore throat, chest pain, difficulty breathing and swallowing, as well as bleeding inside and outside of the body.

After an incubation period of between two and 21 days, the Ebola virus can cause death a few days later in particularly virulent cases in which the body organs shut down and internal bleeding becomes unstoppable.

People who fall sick with the disease tend to vomit, have diarrhea and suffer both internal and external bleeding, with their bodies often “covered in virus,” explained Dr. Peter Piot, the founding executive director of UNAIDS and under secretary-general of the United Nations from 1995 until 2008.

He’s the microbiologist and physician who co-discovered Ebola and now directs the London School of Hygiene and Tropical Medicine.

The Ebola virus has alarmed international health officials because the frequency of international air travel has increased the possibility the outbreak of the virus in one nation might quickly be transmitted to other countries by patients in the incubation phase of the infection.

The virus is also a serious threat to health-care workers administering health treatments for the illness.

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