Fewer than half of Saudi Arabian patients in a study passed the Middle East Respiratory Syndrome virus to household members, and many of those who developed secondary infections contracted mild cases of MERS, global researchers reported on Wednesday. The study, published in the New England Journal of Medicine, confirmed observations that the virus can cause mild disease, but overall transmission rates are low. "If less than half of infected patients transmit the virus to contacts, such as in this study, we can be pretty sure that this virus will not be able to start an epidemic in humans," said co-author Christian Drosten of the Institute of Virology at the University of Bonn Medical Center.
MERS, thought to originate in camels, causes coughing, fever and pneumonia, and kills about a third of its victims. Understanding how MERS is transmitted has been a quest for doctors trying to quell the outbreak that emerged in the Middle East in 2012 and has infected more than 850 people and killed 333 worldwide.