WHO has published a new risk assessment on MERS. It's a PDF and well worth downloading. Among the key points:
• Most cases are now likely acquired through human-to-human contact.
• Two large nosocomial (in-hospital) outbreaks in the UAE and Saudi Arabia may reflect "inadequate infection prevention and control measures." Alternatively, the virus has greater transmissibility. Mild cases may be missed at current surveillance levels.
• The animal or environmental source of human infections is still unknown and more will likely be infected until the source is identified and the chain broken.
• More exported cases are likely; continuing transmission from those cases will depend on the receiving countries' ability to detect MERS and implement prevention and control measures.
• "Urgent investigations are required to better understand the transmission pattern of this virus. The most urgent include detailed outbreak investigations, case-control studies to understand risj factors for infection, enhacing community studies and surveillance of community-acquired pneumonia ... [N]o control will be possible until the transmission from the animal/environment source to humans is understood and interrupted."