NBC freelance cameraman, Ashoka Mukpo, aged 33 years, became the fourth American to test positive for Ebola. He was in Liberia when diagnosed and has been flown back to the United States to be treated for the disease. He felt tired and achy and had other symptoms on Wednesday after it was found that he had a slight fever following a routine temperature check. He quarantined himself and sought medical advice. The Medicins Sans Frontieres (MSF) treatment center ran tests where he was found positive for the virus.

“The good news is this young man, our colleague, was admitted very, very early,” said NBC News Chief Medical Editor and Corresondent Dr. Nancy Snyderman, adding that neither she nor the other three NBC employees had shown any symptoms or warning signs of Ebola infection.

“We observe the custom now, which is to not shake hands, to not embrace people, to wash our hands with diluted bleach water before we enter the hotel,” said Dr. Snyderman. “We dip our feet in bleach solution.”

The Ebola outbreak has already claimed the lives of 3,330 people in four West  African countries and has become the world’s worst outbreak. U.S. President Barack Obama has pledged federal support to contain the spread in the United States following the case of a Liberian man that was diagnosed in Texas on Tuesday.