Human SARS-CoV infection originated from the direct contact between humans and civets in market or restaurants. Closing wet markets and cleaning civets cut off  the spread chain  of SARS-CoV  and effectively  ended the SARS epidemic. In contrast, MERS-CoV is believed to have existed  in camels for a very long time and camels are widely distributed in Middle East and African countries, serving as important transport vectors  and sources of meat and milk for the local population.