The biggest risk that Middle East Respiratory Syndrome will become a global epidemic, ironically, may lie with globe-trotting healthcare workers. From Houston to Manila, doctors and nurses are recruited for lucrative postings in Saudi Arabia, where MERS was first identified in 2012. Because the kingdom has stepped up hiring of foreign healthcare professionals in the last few years, disease experts said, there is a good chance the MERS virus will hitch a ride on workers as they return home. “This is how MERS might spread around the world,” said infectious disease expert Dr Amesh Adalja of the University of Pittsburgh Medical Center. It can take five to 14 days for someone infected with MERS to show symptoms, more than enough time for a contagious person to fly to the other side of the world without being detectable. Healthcare workers “are at extremely high risk of contracting MERS compared to the general public,” Adalja said. The threat has attracted new attention with the confirmation of the first two MERS cases in the United States. Both are healthcare workers who fell ill shortly after leaving their work in Saudi hospitals and boarding planes bound west. About one-third of the MERS cases treated in hospitals in the Saudi Red Sea city of Jeddah were healthcare workers, according to the World Health Organization. Despite the risk, few of the healthcare workers now in, or planning to go to, Saudi Arabia are having second thoughts about working there, according to nurses, doctors and recruiters interviewed by Reuters. More