RIYADH — Authorities closed an emergency ward in one of the Kingdom's largest hospitals after at least 46 people, including hospital staff, contracted the potentially fatal Middle East respiratory syndrome, also known as MERS, a health official said Wednesday. Dr. Hanan Balkhi of the Health Ministry's department for infectious diseases said that of the 46 people infected at King Abdulaziz Medical City in the capital, Riyadh, 15 were medical staff. Another 20 people showing symptoms are currently being tested to see if they have contracted the virus, she added. The patients from the ward, which is to remain closed for two weeks, are being transferred to other hospitals, she said. Before Balkhi's statement, the Health Ministry had said that 480 people have died of the coronavirus since it was first identified in 2012. The ministry said Tuesday that about 1,115 cases have been registered nationwide; 590 have recovered and the rest are being treated. According to Helen Branswell, one of the favorite infectious disease reporters, the Kingdom has not seen that many infections in a day since the height of the MERS outbreak last year. This is especially concerning as travelers begin to arrive for the Haj, the annual pilgrimage to Islam's holy sites that falls between Sept. 20 and 25 this year. Over the course of the pilgrimage, Saudia Arabia hosts more than 2 million people, who sleep in hot shared tents and travel barefoot toward their destinations. Those conditions make it extraordinarily easy for a virus like MERS to spread — especially devastating because MERS kills about 50 percent of the people it infects. Saudi Arabia has not yet posted its health regulations for 2015 Haj travelers. Most MERS cases have been diagnosed in the Middle East, primarily in Saudi Arabia. The MERS virus belongs to the family of viruses known as coronaviruses, which include both the common cold and SARS, or severe acute respiratory syndrome. SARS killed some 800 people in a global outbreak in 2003. The MERS virus can cause symptoms such as fever, breathing problems, pneumonia and kidney failure. — Agencies