A U.S. citizen who recently returned from China has been diagnosed with the new virus unleashed in the Asian country and has forced it to impose sanitary measures in various countries. The man returned to Seattle in the middle of last week after traveling to the Wuhan area, where the outbreak began. The individual is in 30 years old and in good condition at the hospital in Everett, outside Seattle, the United States is the fifth country to report cases of the disease after China, Thailand, Japan and South Korea.At the end of last week , U.S. health officials began checking passengers from central China at U.S. airports. Health workers around the world have implemented similar checks at airports in the hope of containing the virus during the busy Lunar New Year holiday season.Last month, doctors began recording a new type of viral pneumonia with symptoms such as fever, cough and shortness of breath, in people who spent time at a food market in Wuhan. More than 275 cases of the newly identified coronavirus have been confirmed in China, most of them in Wuhan, according to the World Health Organization.The authorities said it probably spread from animals to humans, but this week officials Chinese concluded that it can also spread among humans. Announcing the reviews at the airport last week, employees of the U.S. Centers for Disease Control and Prevention (CDC) said that the risk to Americans was low, but that the disease would likely appear in some time in the United States.