Following the outbreak of severe acute respiratory syndrome (SARS) in China in 2003, the Government enhanced infectious disease surveillance, building the web-based Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS) in 2004. It enabled all the healthcare institutes across the country to report, in real time, individual case information of notifiable infectious diseases through the Internet.
According to the Law of Prevention and Control of Infectious Disease in China, 39 infectious diseases are regulated as notifiable diseases, classified as A, B or C according to their epidemic levels and potential population threats. Groups A and B (a total of 28 diseases) represent categories of diseases with high risk of outbreaks or that are likely to result in rapid spread once an outbreak occurs.
Mortality and morbidity related to group A and B diseases are reported and published by the Ministry of Health on a monthly basis. Group C diseases are less infectious and, when outbreaks occur, are epidemiologically less severe. They are required to be reported only when outbreaks occur. Conditions for timely reporting impose that group A diseases are to be reported within 2 hours while group B and C diseases can be done within 24 hours.