Breaking News: Another American male doctor contracts deadly virus while working in Liberia

An American male doctor has contracted the Ebola virus while working at a hospital in Liberia it was confirmed today as the CDC warned that the deadly disease was spiraling out of control.

The unnamed doctor had been treating women in the obstetrics ward of a hospital in the Liberian capital, his charity Serving In Mission said on Tuesday. 

The group doesn't know how the doctor contracted Ebola since the ward is separate from the zone where Ebola patients are being treated.

The doctor did not work in an Ebola ward. The group did not specify how he contracted Ebola, but it can be spread through vaginal fluids.

Dr Thomas Frieden, director of the Centers for Disease Control and Prevention, who just returned from West Africa, said today that the world's worst Ebola outbreak is threatening the stability of affected and neighboring countries and a 'massive' response is needed to bring it under control.

Dr Frieden said: 'We're likely to see significant increases in cases. Already we have widespread transmission Liberia. In Sierra Leone, we're seeing strong signs that that will happen in the near future.'

The group, Doctor Without Borders (Medecins Sans Frontieres - MSF), also warned on Tuesday that the world is losing the battle against the disease and said treatment centers have been 'reduced to places where people go to die alone' as authorities race to contain the disease.

Doctors Without Borders President Joanne Liu said her organization is completely overwhelmed by Ebola outbreak in four West African countries - Guinea, Liberia, Sierra Leone and Nigeria.

She called on other countries to contribute civilian and military medical personnel familiar with biological disasters. 

More than 1,500 people have died across West Africa from Ebola.

A statement from SIM today read: 'Upon onset of the symptoms, the doctor immediately isolated himself and has since been transferred to the ELWA Ebola isolation unit.

'The doctor is doing well and is in good spirits.' 

Bruce Johnson, president of SIM USA, said today: 'My heart was deeply saddened, but my faith was not shaken, when I learned another of our missionary doctors contracted Ebola. 

Picture of Nancy Writebol who works in Liberia and has also been diagnosed with the disease.

Earlier on Tuesday, the U.N. Food and Agriculture Organization warned that food in countries hit by Ebola is becoming more expensive and will become scarcer as farmers can't reach their fields.

Authorities have cordoned off entire towns in an effort to halt the virus' spread. Surrounding countries have closed land borders, airlines have suspended flights to and from the affected countries and seaports are losing traffic, restricting food imports to the hardest-hit countries. 

Those countries - Guinea, Liberia and Sierra Leone - all rely on grain from abroad to feed their people, according to the U.N. FAO.

For instance, the price of cassava root, a staple in many West African diets, has gone up 150 percent in one market in Liberia's capital, Monrovia.

'Even prior to the Ebola outbreak, households in some of the affected areas were spending up to 80 percent of their incomes on food,' said Vincent Martin, who is coordinating the food agency's response to the crisis. 'Now these latest price spikes are effectively putting food completely out of their reach.'

An estimated 1.3 million people in Guinea, Liberia and Sierra Leone will soon need help feeding themselves, said the U.N.

Chan and other officials at the U.N. forum criticized the border closures because they are preventing supplies from reaching people in desperate need.

'The three worst-hit countries are isolated,' Chan said. 'We cannot fly in our experts for help.'

The situation will likely worsen because restrictions on movement are preventing laborers from getting to farms and the harvest of rice and corn is set to begin in just a few weeks, the FAO said.

Ivory Coast decided Monday night to keep its borders with Guinea and Liberia closed but said it would open a humanitarian corridor to allow supplies in.

A separate Ebola outbreak has hit a remote part of Congo, in Central Africa, the traditional home of the disease. So far, 53 cases consistent with Ebola have been identified there, of whom 31 have died, WHO said today. 

 Obstetrics Unit of Elwa hospital in Monrovia (pictured above), where the American male doctor contacted the deadly Ebola virus.