The World Health Organization is asking health workers around the world to be on alert for symptoms of the deadly Middle East Respiratory Syndrome (MERS) coronavirus.
Monday's warning came as WHO officials ended a six-day investigation in Saudi Arabia, where 40 of the 55 cases of the respiratory disease have occurred. Sixty percent of those people with known infections died.
The United Nations agency is concerned that the MERS virus might spread among pilgrims expected to visit holy sites in Saudi Arabia next month during Ramadan, or the millions more expected in October for the annual Hajj to Mecca.
Officials are also worried that guest workers in the kingdom could carry the virus home to other countries, possibly causing a global pandemic.
Travelers have carried the virus to Britain, France, Germany and Italy. Infected people have also been found in Jordan, Qatar, Tunisia and the United Arab Emirates.