Gaps remain in China's ability to detect emerging infectious diseases despite advances since the onset of SARS and avian flu.

Early detection of emerging infections in China is critical to the health of the 1.3 billion Chinese people and to the world. China's surveillance system for endemic infectious diseases has improved greatly since 2003, but the country's ability to conduct surveillance for laboratory-confirmed infections remains underdeveloped. This is dangerous for China, the world's most populous country, which has been the focus of global attention since outbreaks of severe acute respiratory syndrome (SARS) and avian influenza. We describe China's public health advances since the 2003 SARS outbreak and conclude that China must now invest far more in pathogen-based surveillance. An enhanced disease-detection system in China will help prevent and contain outbreaks before they cause substantial illness and death in China and other countries.