SARS had killed 774 people and sickened 8,098, mainly in mainland China and Hong Kong. The response this time has been much quicker, and countries around the world are enforcing tougher measures to contain the disease. China has placed around 50 million people under quarantine, mainly in and around Wuhan, the hardest-hit central Chinese city where the virus was first detected in December among people who had visited a food market where live wild animals were sold.